Roofing

Roofs play a key role in protecting building occupants and interiors from outside weather conditions, primarily moisture. The roof, insulation and ventilation must all work together 

to keep the building free of moisture. Roofs also provide protection from the sun. In fact, if designed correctly, roof overhangs can protect the building's exterior walls from moisture and sun. The concerns regarding moisture, standing water, durability and appearance are different, reflected in the choices of roofing materials.

Maintaining Your Roof

  

Homeowner maintenance includes cleaning the leaves and debris from the roof’s valleys and gutters. Debris in the valleys can cause water to wick under the shingles and cause damage to the interior of the roof. Clogged rain gutters can cause water to flow back under the shingles on the eaves and cause damage, regardless of the roofing material. including composition shingle, wood shake, tile or metal. The best way to preserve your roof is to stay off it. Also, seasonal changes in the weather are usually the most destructive forces.

A leaky roof can damage ceilings, walls and furnishings. To protect buildings and their contents from water damage, roofers repair and install roofs made of tar or asphalt and gravel; rubber or thermoplastic; metal; or shingles made of asphalt, slate, fiberglass, wood, tile, or other material. Roofers also may waterproof foundation walls and floors.

There are two types of roofs:  flat and pitched (sloped). Most commercial, industrial and apartment buildings have flat or slightly sloping roofs. Most houses have pitched roofs. Some roofers work on both types; others specialize. Most flat roofs are covered with several layers of materials. Roofers first put a layer of insulation on the roof deck. Over the insulation, they then spread a coat of molten bitumen, a tar-like substance. Next, they install partially overlapping layers of roofing felt, a fabric saturated in bitumen, over the surface. Roofers use a mop to spread hot bitumen over the surface and under the next layer. This seals the seams and makes the surface watertight. Roofers repeat these steps to build up the desired number of layers, called plies. The top layer either is glazed to make a smooth finish or has gravel embedded in the hot bitumen to create a rough surface. An increasing number of flat roofs are covered with a single-ply membrane of waterproof rubber or thermoplastic compounds. Roofers roll these sheets over the roof’s insulation and seal the seams. Adhesive mechanical fasteners, or stone ballast hold the sheets in place. The building must be of sufficient strength to hold the ballast.

Most residential roofs are covered with shingles. To apply shingles, roofers first lay, cut, and tack 3-foot strips of roofing felt lengthwise over the entire roof. Then, starting from the bottom edge, they staple or nail overlapping rows of shingles to the roof. Workers measure and cut the felt and shingles to fit intersecting roof surfaces and to fit around vent pipes and chimneys. Wherever two roof surfaces intersect, or where shingles reach a vent pipe or chimney, roofers cement or nail flashing strips of metal or shingle over the joints to make them watertight. Finally, roofers cover exposed nailheads with roofing cement or caulking to prevent water leakage. Roofers who use tile, metal shingles or shakes follow a similar process. Some roofers also water-proof and damp-proof masonry and concrete walls and floors. To prepare surfaces for waterproofing, they hammer and chisel away rough spots, or remove them with a rubbing brick, before applying a coat of liquid waterproofing compound. They also may paint or spray surfaces with a waterproofing material, or attach a waterproofing membrane to surfaces. When damp-proofing, they usually spray a bitumen-based coating on interior or exterior surfaces.

A number of roofing materials are available...  

Asphalt

Asphalt is the most commonly used roofing material. Asphalt products include shingles, roll-roofing, built-up roofing, and modified bitumen membranes. Asphalt shingles are typically the most common and economical choice for residential roofing. They come in a variety of colors, shapes and textures. There are four different types: strip, laminated, interlocking, and large individual shingles. Laminated shingles consist of more than one layer of tabs to provide extra thickness. Interlocking shingles are used to provide greater wind resistance. And large individual shingles generally come in rectangular and hexagonal shapes. Roll-roofing products are generally used in residential applications, mostly for underlayments and flashings. They come in four different types of material: smooth-surfaced, saturated felt, specialty-eaves flashings, and mineral-surfaced. Only mineral-surfaced is used alone as a primary roof covering for small buildings, such as sheds. Smooth-surfaced products are used primarily as flashing to seal the roof at intersections and protrusions, and for providing extra deck protection at the roof's eaves and valleys. Saturated felt is used as an underlayment between the roof deck and the roofing material. Specialty-eaves flashings are typically used in climates where ice dams and water backups are common. Built-up roofing (or BUR) is the most popular choice of roofing used on commercial, industrial and institutional buildings. BUR is used on flat and low-sloped roofs and consists of multiple layers of bitumen and ply sheets. Components of a BUR system include the roof deck, a vapor retarder, insulation, membrane, and surfacing material. A modified bitumen-membrane assembly consists of continuous plies of saturated felts, coated felts, fabrics or mats between which alternate layers of bitumen are applied, either surfaced or unsurfaced. Factory surfacing, if applied, includes mineral granules, slag, aluminum or copper. The bitumen determines the membrane's physical characteristics and provides primary waterproofing protection, while the reinforcement adds strength, puncture-resistance and overall system integrity.

Metal

Most metal roofing products consist of steel or aluminum, although some consist of copper and other metals. Steel is invariably galvanized by the application of a zinc or a zinc-aluminum coating, which greatly reduces the rate of corrosion. Metal roofing is available as traditional seam and batten, tiles, shingles and shakes. Products also come in a variety of styles and colors. Metal roofs with solid sheathing control noise from rain, hail and bad weather just as well as any other roofing material. Metal roofing can also help eliminate ice damming at the eaves. And in wildfire-prone areas, metal roofing helps protect buildings from fire, should burning embers land on the roof. Metal roofing costs more than asphalt, but it typically lasts two to three times longer than asphalt and wood shingles.

Wood

Wood shakes offer a natural look with a lot of character. Because of variations in color, width, thickness, and cut of the wood, no two shake roofs will ever look the same. Wood offers some energy benefits, too. It helps to insulate the attic, and it allows the house to breathe, circulating air through the small openings under the felt rows on which wooden shingles are laid. A wood shake roof, however, demands proper maintenance and repair, or it will not last as long as other products. Mold, rot and insects can become a problem. The life-cycle cost of a shake roof may be high, and old shakes can't be recycled. Most wood shakes are unrated by fire safety codes. Many use wipe or spray-on fire retardants, which offer less protection and are only effective for a few years. Some pressure-treated shakes are impregnated with fire retardant and meet national fire safety standards. Installing wood shakes is more complicated than roofing with composite shingles, and the quality of the finished roof depends on the experience of the contractor, as well as the caliber of the shakes used. The best shakes come from the heartwood of large, old cedar trees, which are difficult to find. Some contractors maintain that shakes made from the outer wood of smaller cedars, the usual source today, are less uniform, more subject to twisting and warping, and don't last as long.

Concrete and Tile

Concrete tiles are made of extruded concrete that is colored. Traditional roofing tiles are made from clay. Concrete and clay tile roofing systems are durable, aesthetically appealing, and low in maintenance. They also provide energy savings and are environmentally friendly. Although material and installation costs are higher for concrete and clay tile roofs, when evaluated on a price-versus-performance basis, they may out-perform other roofing materials. Tile adorns the roofs of many historic buildings, as well as modern structures. In fact, because of its extreme durability, longevity and safety, roof tile is the most prevalent roofing material in the world. Tested over centuries, roof tile can successfully withstand the most extreme weather conditions including hail, high wind, earthquakes, scorching heat, and harsh freeze-thaw cycles. Concrete and clay roof tiles also have unconditional Class A fire ratings, which means that, when installed according to building code, roof tile is non-combustible and maintains that quality throughout its lifetime. In recent years, manufacturers have developed new water-shedding techniques and, for high-wind situations, new adhesives and mechanical fasteners. Because the ultimate longevity of a tile roof also depends on the quality of the sub-roof, roof tile manufacturers are also working to improve flashings and other aspects of the underlayment system. Under normal circumstances, properly installed tile roofs are virtually maintenance-free. Unlike other roofing materials, roof tiles actually become stronger over time. Because of roof tile's superior quality and minimal maintenance requirements, most roof tile manufacturers offer warranties that range from 50 years to the lifetime of the structure.

Concrete and clay tile roofing systems are also energy-efficient, helping to maintain livable interior temperatures (in both cold and warm climates) at a lower cost than other roofing systems. Because of the thermal capacity of roof tiles and the ventilated air space that their placement on the roof surface creates, a tile roof can lower air-conditioning costs in hotter climates, and produce more constant temperatures in colder regions, which reduces potential ice accumulation. Tile roofing systems are made from naturally occurring materials and can be easily recycled into new tiles or other useful products. They are produced without the use of chemical preservatives, and do not deplete limited natural resources.

Single-Ply

Single-ply membranes are flexible sheets of compounded synthetic materials that are manufactured in a factory. There are three types of membranes: thermosets, thermoplastics, and modified bitumens. These materials provide strength, flexibility, and long-lasting durability. The advantages of pre-fabricated sheets are the consistency of the product quality, the versatility in their attachment methods, and, therefore, their broader applicability. They are inherently flexible, used in a variety of attachment systems, and compounded for long-lasting durability and watertight integrity for years of roof life. Thermoset membranes are compounded from rubber polymers. The most commonly used polymer is EPDM (often referred to as "rubber roofing"). Thermoset membranes make successful roofing materials because they can withstand the potentially damaging effects of sunlight and most common chemicals generally found on roofs. The easiest way to identify a thermoset membrane is by its seams, which require the use of adhesive, either liquid or tape, to form a watertight seal at the overlaps. Thermoplastic membranes are based on plastic polymers. The most common thermoplastic is PVC (polyvinyl chloride) which has been made flexible through the inclusion of certain ingredients called plasticizers. Thermoplastic membranes are identified by seams that are formed using either heat or chemical welding. These seams are as strong or stronger than the membrane itself. Most thermoplastic membranes are manufactured to include a reinforcement layer, usually polyester or fiberglass, which provides increased strength and dimensional stability. Modified bitumen membranes are hybrids that incorporate the high-tech formulation and pre-fabrication advantages of single-ply with some of the traditional installation techniques used in built-up roofing. These materials are factory-fabricated layers of asphalt, "modified" using a rubber or plastic ingredient for increased flexibility, and combined with reinforcement for added strength and stability. There are two primary modifiers used today: APP (atactic polypropylene) and SBS (styrene butadiene styrene). The type of modifier used may determine the method of sheet installation. Some are mopped down using hot asphalt, and some use torches to melt the asphalt so that it flows onto the substrate. The seams are sealed by the same technique.

Are You at Risk?

If you aren't sure whether your house is at risk from natural disasters, check with your local fire marshal, building official, city engineer, or planning and zoning administrator. They can tell you whether you are in a hazard area. Also, they usually can tell you how to protect yourself and your house and property from damage. It is never a bad idea to ask an InterNACHI inspector whether your roof is in need of repair during your next scheduled inspection. Protection can involve a variety of changes to your house and property which that can vary in complexity and cost. You may be able to make some types of changes yourself. But complicated or large-scale changes and those that affect the structure of your house or its electrical wiring and plumbing should be carried out only by a professional contractor licensed to work in your state, county or city. One example is fire protection, accomplished by replacing flammable roofing materials with fire-resistant materials. This is something that most homeowners would probably hire a contractor to do.

  

Replacing Your Roof

  

The age of your roof is usually the major factor in determining when to replace it. Most roofs last many years, if properly installed, and often can be repaired rather than replaced. An isolated leak usually can be repaired. The average life expectancy of a typical residential roof is 15 to 20 years. Water damage to a home’s interior or overhangs is commonly caused by leaks from a single weathered portion of the roof, poorly installed flashing, or from around chimneys and skylights. These problems do not necessarily mean you need a new roof.

Fire-Resistant Materials

Some roofing materials, including asphalt shingles, and especially wood shakes, are less resistant to fire than others. When wildfires and brush fires spread to houses, it is often because burning branches, leaves, and other debris buoyed by the heated air and carried by the wind fall onto roofs. If the roof of your house is covered with wood or asphalt shingles, you should consider replacing them with fire-resistant materials. You can replace your existing roofing materials with slate, terra cotta or other types of tile, or standing-seam metal roofing. Replacing roofing materials is difficult and dangerous work. Unless you are skilled in roofing and have all the necessary tools and equipment, you will probably want to hire a roofing contractor to do the work. Also, a roofing contractor can advise you on the relative advantages and disadvantages of various fire-resistant roofing materials.

  

Hiring a Licensed Contractor

One of the best ways to select a roofing contractor is to ask friends and relatives for recommendations. You may also contact a professional roofers association for referrals. Professional associations have stringent guidelines for their members to follow. The roofers association in your area will provide you with a list of available contractors. Follow these guidlines when selecting a contractor:

• get three references and review their past work;
• get at least three bids; 
• get a written contract, and don’t sign anything until you completely understand the terms; 
• pay 10% down or $1,000 whichever is less; 
• don’t let payments get ahead of the work; 
• don’t pay cash; 
• don’t make final payment until you’re satisfied with the job; and 
• don’t rush into repairs or be pressured into making an immediate decision.

You’ve Chosen the Contractor... What About the Contract?

Make sure everything is in writing. The contract is one of the best ways to prevent problems before you begin. The contract protects you and the contractor by including everything you have both agreed upon. Get all promises in writing and spell out exactly what the contractor will and will not do.

...and Permits?

Your contract should call for all work to be performed in accordance with all applicable building codes. The building codes set minimum safety standards for construction. Generally, a building permit is required whenever structural work is involved. The contractor should obtain all necessary building permits. If this is not specified in the contract, you may be held legally responsible for failure to obtain the required permits. The building department will inspect your roof when the project has reached a certain stage, and again when the roof is completed.

...and Insurance?

Make sure the contractor carries workers' compensation insurance and general liability insurance in case of accidents on the job. Ask to have copies of these policies for your job file. You should protect yourself from mechanics’ liens against your home in the event the contractor does not pay subcontractors or material suppliers. You may be able to protect yourself by having a "release of lien" clause in your contract. A release of lien clause requires the contractor, subcontractors and suppliers to furnish a "certificate of waiver of lien." If you are financing your project, the bank or lending institution may require that the contractor, subcontractors and suppliers verify that they have been paid before releasing funds for subsequent phases of the project.

Keep these points in mind if you plan to have your existing roofing materials replaced:

• Tile, metal, and slate are more expensive roofing materials, but if you need to replace your roofing anyway, it may be worthwhile to pay a little more for the added protection these materials provide. 
• Slate and tile can be much heavier than asphalt shingles or wood shingles. If you are considering switching to one of these heavier coverings, your roofing contractor should determine whether the framing of your roof is strong enough to support them. 
• If you live in an area where snow loads are a problem, consider switching to a modern standing-seam metal roof, which will usually shed snow efficiently.

For the best home inspection in the San Antonio, TX area, including the roof, contact Veteran Home Inspections.

Radon

Home Buyer's and Seller's Guide to Radon 

The EPA recommends:

• If you are buying a home or selling your home, have it tested for radon. 
   
• For a new home, ask if radon-resistant construction features were used and if the home has been tested. 
   
• Fix the home if the radon level is 4 picoCuries per liter (pCi/L) or higher. 
   
• Radon levels less than 4 pCi/L still pose a risk, and in many cases, may be reduced. 
   
• Take steps to prevent device interference when conducting a radon test.

The EPA estimates that radon causes thousands of cancer deaths in the U.S. each year.

 * Radon is estimated to cause about 21,000 lung cancer deaths per year.

The numbers of deaths from other causes are taken from the Centers for Disease Control and Prevention's 1999-2001 National Center for Injury Prevention and Control Report and 2002 National Safety Council Reports.

Radon is a cancer-causing, radioactive gas.

You cannot see, smell or taste radon. But it still may be a problem in your home.  When you breathe air containing radon, you increase your risk of getting lung cancer.  In fact, the Surgeon General of the United States has warned that radon is the second leading cause of lung cancer in the United States today.  If you smoke and your home has high radon levels, your risk of lung cancer is especially high.

You should test for radon.

Testing is the only way to find out your home's radon levels. The EPA and the Surgeon General recommend testing all homes below the third floor for radon.

You can fix a radon problem.

If you find that you have high radon levels, there are ways to fix a radon problem. Even very high levels can be reduced to acceptable levels.

If You Are Selling a Home...

The EPA recommends that you test your home before putting it on the market and, if necessary, lower your radon levels. Save the test results and all information you have about steps that were taken to fix any problems. This could be a positive selling point. 

If You Are Buying a Home...

The EPA recommends that you know what the indoor radon level is in any home you are considering buying.  Ask the seller for their radon test results.  If the home has a radon-reduction system, ask the seller for information they have about the system.

If the home has not yet been tested, you should have the house tested.

If you are having a new home built, there are features that can be incorporated into your home during construction to reduce radon levels.

These radon testing guidelines have been developed specifically to deal with the time-sensitive nature of home purchases and sales, and the potential for radon device interference.  These guidelines are slightly different from the guidelines in other EPA publications which provide radon testing and reduction information for non-real estate situations.

This guide recommends three short-term testing options for real estate transactions.  The EPA also recommends testing a home in the lowest level which is currently suitable for occupancy, since a buyer may choose to live in a lower area of the home than that used by the seller.

1. Why do you need to test for radon?

a. Radon has been found in homes all over the U.S.

Radon is a radioactive gas that has been found in homes all over the United States. It comes from the natural breakdown of uranium in soil, rock and water, and gets into the air you breathe. Radon typically moves up through the ground to the air above, and into your home through cracks and other holes in the foundation. Radon can also enter your home through well water. Your home can trap radon inside.

Any home can have a radon problem, including new and old homes, well-sealed and drafty homes, and homes with or without basements. In fact, you and your family are most likely to get your greatest radiation exposure at home. That is where you spend most of your time.

Nearly one out of every 15 homes in the United States is estimated to have an elevated radon level (4 pCi/L or more).  Elevated levels of radon gas have been found in homes in your state. 

b. The EPA and the Surgeon General recommend that you test your home.

Testing is the only way to know if you and your family are at risk from radon. The EPA and the Surgeon General recommend testing all homes below the third floor for radon.

You cannot predict radon levels based on state, local, or neighborhood radon measurements.  Do not rely on radon test results taken in other homes in the neighborhood to estimate the radon level in your home.  Homes which are next to each other can have different radon levels.  Testing is the only way to find out what your home's radon level is.

In some areas, companies may offer different types of radon service agreements.  Some agreements let you pay a one-time fee that covers both testing and radon mitigation, if needed.  

U.S. Surgeon General's
Health Advisory

"Indoor radon gas is the second-leading cause of lung cancer in the United States, and breathing it over prolonged periods can present a significant health risk to families all over the country.  It's important to know that this threat is completely preventable.  Radon can be detected with a simple test, and fixed through well-established venting techniques." 

 January 2005 

2. I'm selling a home.  What should I do? 

a. If your home has already been tested for radon...

If you are thinking of selling your home and you have already tested your home for radon, review the Radon Testing Checklist to make sure that the test was done correctly.  If so, provide your test results to the buyer.

No matter what kind of test you took, a potential buyer may ask for a new test, especially if:

the Radon Testing Checklist items were not met;

the last test is not recent, (e.g., within two years);

you have renovated or altered your home since you tested; or

the buyer plans to live in a lower level of the house than was tested, such as a basement suitable for occupancy but not currently lived in.

A buyer may also ask for a new test if your state or local government requires disclosure of radon information to buyers.

b. If your home has not yet been tested for radon...

Have a test taken as soon as possible. If you can, test your home before putting it on the market.  You should test in the lowest level of the home which is suitable for occupancy. This means testing in the lowest level that you currently live in or a lower level not currently used, but which a buyer could use for living space without renovations. 

The radon test result is important information about your home's radon level.  Some states require radon measurement testers to follow a specific testing protocol.  If you do the test yourself, you should carefully follow the testing protocol for your area or the EPA's Radon Testing Checklist.  If you hire a contractor to test your residence, protect yourself by hiring a qualified individual or company.

You can determine a service provider's qualifications to perform radon measurements or to mitigate your home in several ways.  Many states require radon professionals to be licensed, certified or registered.  Most states can provide you with a list of knowledgeable radon service providers doing business in your state.  In states that don't regulate radon services, ask the contractor if they hold a professional proficiency or certification credential. Such programs usually provide members with a photo-ID card which indicates their qualification(s) and its expiration date.  If in doubt, you should check with their credentialing organization.  Alternatively, ask the contractor if they've successfully completed formal training appropriate for testing or mitigation, e.g., a course in radon measurement or radon mitigation. 

3. I'm buying a home.  What should I do?

a. If the home has already been tested for radon...

If you are thinking of buying a home, you may decide to accept an earlier test result from the seller, or ask the seller for a new test to be conducted by a qualified radon tester.  Before you accept the seller's test, you should determine the results of previous testing by finding out:

who conducted the previous test (the homeowner, a radon professional, or some other person);

where in the home the previous test was taken, especially if you may plan to live in a lower level of the home.  For example, the test may have been taken on the first floor.  However, if you want to use the basement as living space, test there, too;

what, if any, structural changes, alterations, or changes in the heating, ventilation, and air conditioning (HVAC) system have been made to the house since the test was done.  Such changes may affect radon levels.

If you accept the seller's test, make sure that the test followed the Radon Testing Checklist.  

If you decide that a new test is needed, discuss it with the seller as soon as possible. 

b. If the home has not yet been tested for radon...

Make sure that a radon test is done as soon as possible. Consider including provisions in the contract specifying:

where the test will be located;

who should conduct the test;

what type of test to do;

when to do the test;

how the seller and the buyer will share the test results and test costs (if necessary); and

when radon mitigation measures will be taken, and who will pay for them.

Make sure that the test is done in the lowest level of the home suitable for occupancy. This means the lowest level that you are going to use as living space which is finished or does not require renovations prior to use. A state or local radon official or qualified radon tester can help you make some of these decisions. If you decide to finish or renovate an unfinished area of the home in the future, a radon test should be taken before starting the project, and after the project is finished. Generally, it is less expensive to install a radon-reduction system before (or during) renovations rather than afterward.

4. I'm buying or building a new home.  How can I protect my family?

a. Why should I buy a radon-resistant home?

Radon-resistant techniques work.  When installed properly and completely, these simple and inexpensive passive techniques can help to reduce radon levels.  In addition, installing them at the time of construction makes it easier to reduce radon levels further if the passive techniques don't reduce radon levels below 4 pCi/L.  Radon-resistant techniques may also help to lower moisture levels and those of other soil-gases.  Radon-resistant techniques:

	make upgrading easy:  Even if built to be radon-resistant, every new home should be tested for radon after occupancy.  If you have a test result of 4 pCi/L or more, a vent fan can easily be added to the passive system to make it an active system, and further reduce radon levels.
	are cost-effective:  Building radon-resistant features into the house during construction is easier and cheaper than fixing a radon problem from scratch later.  Let your builder know that radon-resistant features are easy to install using common building materials.
	save money:  When installed properly and completely, radon-resistant techniques can also make your home more energy-efficient and help you save on your energy costs.

In a new home, the cost to install passive radon-resistant features during construction is usually between $350 to $500.  In some areas, the cost may be as low as $100.  A qualified mitigator will charge about $300 to add a vent fan to a passive system, making it an active system and further reducing radon levels.  In an existing home, it usually costs between $800 to $2,500 to install a radon mitigation system.

b. What are radon-resistant features?

Radon-resistant features may vary for different foundations and site requirements.  If you're having a house built, you can learn about the EPA's Model Standards (and architectural drawings) and explain the techniques to your builder.  If your new house was built (or will be built) to be radon-resistant, it will include these basic elements:

gas-permeable layer:  This layer is placed beneath the slab or flooring system to allow the soil gas to move freely underneath the house.  In many cases, the material used is a 4-inch layer of clean gravel.  This gas-permeable layer is used only in homes with basement and slab-on-grade foundations; it is not used in homes with crawlspace foundations.    plastic sheeting:  Plastic sheeting is placed on top of the gas-permeable layer and under the slab to help prevent the soil gas from entering the home.  In crawlspaces, the sheeting (with seams sealed) is placed directly over the crawlspace floor.    sealing and caulking:  All below-grade openings in the foundation and walls are sealed to reduce soil-gas entry into the home.    vent pipe:  A 3- or 4-inch PVC pipe (or other gas-tight pipe) runs from the gas-permeable layer through the house to the roof to safely vent radon and other soil gases to the outside.    junction boxes:  An electrical junction box is included in the attic to make the wiring and installation of a vent fan easier, if, for example, you decide to activate the passive system if your test results show an elevated radon level (4 pCi/L or more).  A separate junction box is placed in the living space to power the vent-fan alarm.  An alarm is installed along with the vent fan to indicate when the vent fan is not operating properly.

5. How can I get reliable radon test results?

Radon testing is easy and the only way to find out if you have a radon problem in your home.

a. Types of Radon Devices

Since you cannot see or smell radon, special equipment is needed to detect it.  When you're ready to test your home, you can order a radon test kit by mail from a qualified radon measurement service provider or laboratory.  You can also hire a qualified radon tester, very often a home inspector, who will use the radon device(s) suitable to your situation. If you hire a home inspector, make sure you hire a qualified InterNACHI member -- specifically, an IAC2 certified air-quality professional.  In Maryland, contact Veteran Home Inspections for radon testing.  The most common types of radon testing devices are listed below.  

Passive Devices

Passive radon-testing devices do not need power to function.  These include charcoal canisters, alpha-track detectors, charcoal liquid scintillation devices, and electret ion chamber detectors, which are available in hardware, drugstores, and other stores; they can also be ordered by mail or phone.  These devices are exposed to the air in the home for a specified period of time, and then sent to a laboratory for analysis.  Both short-term and long-term passive devices are generally inexpensive. Some of these devices may have features that offer more resistance to test interference or disturbance than other passive devices. Qualified radon testers may use any of these devices to measure the home's radon level.

Active Devices

Active radon-testing devices require power to function. These include continuous radon monitors and continuous working-level monitors.  They continuously measure and record the amount of radon and its decay products in the air.  Many of these devices provide a report of this information, which can reveal any unusual or abnormal swings in the radon level during the test period. A qualified tester can explain this report to you.  In addition, some of these devices are specifically designed to deter and detect test interference. Some technically advanced active devices offer anti-interference features.  Although these tests may cost more, they may ensure a more reliable result.

b. General Information for All Devices

A state or local radon official can explain the differences between devices, and recommend the ones which are most appropriate for your needs and expected testing conditions.

Make sure to use a radon measurement device from a qualified laboratory.  Certain precautions should be followed to avoid interference during the test period.  See the Radon Testing Checklist for more information on how to get a reliable test result.

Radon Test Device Placement

The EPA recommends that testing device(s) be placed in the lowest level of the home suitable for occupancy. This means testing in the lowest level (such as a basement) which a buyer could use for living space without renovations. The test should be conducted in a room to be used regularly (such as a family room, living room, play room, den or bedroom); do not test in a kitchen, bathroom, laundry room or hallway.  Usually, the buyer decides where to locate the radon test, based on their expected use of the home.  A buyer and seller should explicitly discuss and agree on the test location to avoid any misunderstanding.  Their decision should be clearly communicated to the person performing the test.

c. Preventing or Detecting Test Interference

There is a potential for test interference in real estate transactions. There are several ways to prevent or detect test interference:

Use a test device that frequently records radon or decay-product levels to detect unusual swings.

Employ a motion detector to determine whether the test device has been moved or if testing conditions have changed.

Use a proximity detector to reveal the presence of people in the room, which may correlate to possible changes in radon levels during the test.

Record the barometric pressure to identify weather conditions which may have affected the test.

Record the temperature to help assess whether doors and windows have been opened during the test. 

Apply tamper-proof seals to windows to ensure closed-house conditions.

Have the seller/occupant sign a non-interference agreement.

Home buyers and sellers should consult a qualified radon test provider about the use of these precautions.

d. Length of Time to Test

There are two general ways to test your home for radon:

Because radon levels vary from day to day and from season to season, a short-term test is less likely than a long-term test to tell you your year-round average radon level.  However, if you need results quickly, a short-term test may be used to decide whether to fix the home.

	Short-Term Testing:

The quickest way to test is with short-term tests. Short-term tests remain in your home from two days to 90 days, depending on the device. There are two groups of devices which are more commonly used for short-term testing. The passive-device group includes alpha-track detectors, charcoal canisters, charcoal liquid scintillation detectors, and electret ion chambers. The active device group consists of different types of continuous monitors.

Whether you test for radon yourself, or hire a state-certified tester or a privately certified tester, all radon tests should be taken for a minimum of 48 hours. A longer period of testing is required for some devices.

Long-Term Testing

Long-term tests remain in your home for more than 90 days. Alpha-track andelectret ion chamber detectors are commonly used for this type of testing. A long-term test will give you a reading that is more likely to tell you your home's year-round average radon level than a short-term test. If time permits, long-term tests (more than 90 days) can be used to confirm initial short-term results. When long-term test results are 4 pCi/L or higher, the EPA recommends mitigating the home.

e. Doing a Short-Term Test...

If you are testing in a real estate transaction and you need results quickly, any of the following three options for short-term tests are acceptable in determining whether the home should be fixed. Any real estate test for radon should include steps to prevent or detect interference with the testing device.

When Choosing a Short-Term Testing Option... There are trade-offs among the short-term testing options.  Two tests taken at the same time (simultaneous) would improve the precision of this radon test.  One test followed by another test (sequential) would most likely give a better representation of the seasonal average.  Both active and passive devices may have features which help to prevent test interference.  Your state radon office can help you decide which option is best.

Short-Term Testing Options	What to Do Next
Passive: Take two short-term tests at the same time in the same location for at least 48 hours.   or  Take an initial short-term test for at least 48 hours.  Immediately upon completing the first test, do a second test using an identical device in the same location as the first test.	Fix the home if the average of two tests is 4 pCi/L or more. Fix the home if the average of the two tests is 4 pCi/L or more.
Active: Test the home with a continuous monitor for at least 48 hours.	Fix the home if the average radon level is 4 pCi/L or more.

f.  Using testing devices properly for reliable results.

If you do the test yourself:

When you are taking a short-term test, close windows and doors and keep them closed, except for normal entry and exit.  If you are taking a short-term test lasting less than four days, be sure to:

Close your windows and outside doors at least 12 hours before beginning the test.

Do not conduct short-term tests lasting less than four days during severe storms or periods of high winds.

Follow the testing instructions and record the start time and date.

Place the test device at least 20 inches above the floor in a location where it will not be disturbed and where it will be away from drafts, high heat, high humidity, and exterior walls.

Leave the test kit in place for as long as the test instructions say.

Once you have finished the test, record the stop time and date, re-seal the package, and return it immediately to the lab specified on the package for analysis.

You should receive your test results within a few weeks. If you need results quickly, you should find out how long results will take and, if necessary, request expedited service.

If you hire a qualified radon tester:

In many cases, home buyers and sellers may decide to have the radon test done by a qualified radon tester who knows the proper conditions, test devices, and guidelines for obtaining a reliable radon test result.  They can also:

• evaluate the home and recommend a testing approach designed to make sure you get reliable results;
• explain how proper conditions can be maintained during the radon test;
• emphasize to occupants of a home that a reliable test result depends on their cooperation.  Interference with, or disturbance of, the test or closed-house conditions will invalidate the test result;
• analyze the data and report measurement results; and
• provide an independent test.

g. Interpreting Radon Test Results

The average indoor radon level is estimated to be about 1.3 pCi/L; roughly 0.4 pCi/L of radon is normally found in the outside air. The U.S. Congress has set a long-term goal that indoor radon levels be no more than outdoor levels. While this goal is not yet technologically achievable for all homes, radon levels in many homes can be reduced to 2 pCi/L or below.

Radon Test Results Reported in Two Ways

Your radon test results may be reported in either picoCuries per liter of air (pCi/L) or working levels (WL). If your test result is in pCi/L, the EPA recommends you fix your home if your radon level is 4 pCi/L or higher. If the test result is in WL, the EPA recommends you fix the home if the working level is 0.02 WL or higher.  Some states require WL results to be converted to pCi/L to minimize confusion.

Sometimes, short-term tests are less definitive about whether the home is at or above 4 pCi/L, particularly when the results are close to 4 pCi/L. For example, if the average of two short-term tests is 4.1 pCi/L, there is about a 50% chance that the year-round average is somewhat below 4 pCi/L. 

However, the EPA believes that any radon exposure carries some risk; no level of radon is safe. Even radon levels below 4 pCi/L pose some risk.  You can reduce your risk of lung cancer by lowering your radon level.

As with  other environmental pollutants, there is some uncertainty about the magnitude of radon health risks. However, we know more about radon risks than risks from most other cancer-causing substances. This is because estimates of radon risks are based on data from human studies on underground miners. Additional studies on more typical populations are underway.

Your radon measurement will give you an idea of your risk of getting lung cancer from radon. Your chances of getting lung cancer from radon depend mostly on:

• your home's radon level; 
• the amount of time you spend in your home; and
• whether you are a smoker or have ever smoked.

Smoking combined with radon is an especially serious health risk. If you smoke or are a former smoker, the presence of radon greatly increases your risk of lung cancer. If you stop smoking now and lower the radon level in your house, you will reduce your lung cancer risk.

Based on information contained in the National Academy of Sciences' 1998 report, The Health Effects of Exposure to Indoor Radon, your radon risk may be somewhat higher than shown, especially if you have never smoked.  It's never too late to reduce your risk to lung cancer.  Don't wait to test and fix a radon problem.  If you are a smoker, stop smoking.

Go to the Radon Risk Comparison Charts

Radon Testing Checklist

For reliable test results, follow this Radon Testing Checklist carefully.  Testing for radon is not complicated.  Improper testing may yield inaccurate results and require another test.  Disturbing or interfering with the test device or with closed-house conditions may invalidate the test results, and is actually illegal in some states.  If the seller or qualified tester cannot confirm that all items have been completed, take another test.

Before conducting a radon test:

Notify the occupants of the importance of proper testing conditions. Give the occupants written instructions or a copy of this Guide and explain the directions carefully.

Conduct the radon test for a minimum of 48 hours; some test devices have a minimum exposure time greater than 48 hours.

When doing a short-term test ranging from two to four days, it is important to maintain closed-house conditions for at least 12 hours before the beginning of the test and during the entire test period.

When doing a short-term test ranging from four to seven days, the EPA recommends that closed-house conditions be maintained.

If you conduct the test yourself, use a qualified radon measurement device and follow the laboratory's instructions.  Your state may be able to provide you with a list of do-it-yourself test devices available from qualified laboratories.

If you hire someone to do the test, hire only a qualified individual.  Some states issue photo identification (ID) cards; ask to see it.  The tester's ID number, if available, should be included or noted in the test report.

The test should include method(s) to prevent or detect interference with testing conditions, or with the testing device itself.

If the house has an active radon-reduction system, make sure the vent fan is operating properly.  If the fan is not operating properly, have it (or ask to have it) repaired and then test it.

"Closed-house conditions" mean keeping all windows closed, keeping doors closed except for normal entry and exit, and not operating fans or other machines which bring in air from outside.  Fans that are part of a radon-reduction system or small exhaust fans operating for only short periods of time may run during the test.

During a radon test:

Maintain closed-house conditions during the entire time of a short-term test, especially for tests shorter than one week.

Operate the home's heating and cooling systems normally during the test. For tests lasting less than one week, operate only air-conditioning units which re-circulate interior air.

Do not disturb the test device at any time during the test.

If a radon-reduction system is in place, make sure the system is working properly and will be in operation during the entire radon test.

After a radon test:

If you conduct the test yourself, be sure to promptly return the test device to the laboratory.  Be sure to complete the required information, including start and stop times, test location, etc.

If an elevated level is found, fix the home. Contact a qualified radon-reduction contractor about lowering the radon level.  The EPA recommends that you fix the home when the radon level is 4 pCi/L or more.

Be sure that you or the radon tester can demonstrate or provide information to ensure that the testing conditions were not violated during the testing period.

6. What should I do if the radon level is high?

a. High radon levels can be reduced.

The EPA recommends that you take action to reduce your home's indoor radon levels if your radon test result is 4 pCi/L or higher. It is better to correct a radon problem before placing your home on the market because then you will have more time to address a radon problem. 

If elevated levels are found during the real estate transaction, the buyer and seller should discuss the timing and costs of the radon reduction.  The cost of making repairs to reduce radon levels depends on how your home was built and other factors. Most homes can be fixed for about the same cost as other common home repairs, such as painting or having a new hot water heater installed. The average cost for a contractor to lower radon levels in a home can range from $800 to about $2,500.

b. How to Lower The Radon Level in Your Home

A variety of methods can be used to reduce radon in homes. Sealing cracks and other openings in the foundation is a basic part of most approaches to radon reduction. The EPA does not recommend the use of sealing alone to limit radon entry.  Sealing alone has not been shown to lower radon levels significantly or consistently. 

 In most cases, a system with a vent pipe and fan is used to reduce radon.  These "sub-slab depressurization" systems do not require major changes to your home. Similar systems can also be installed in homes with crawlspaces.  These systems prevent radon gas from entering the home from below the concrete floor and from outside the foundation.  Radon mitigation contractors may use other methods that may also work in your home. The right system depends on the design of your home and other factors. 

Radon and Home Renovations

 If you are planning any major renovations, such as converting an unfinished basement area into living space, it is especially important to test the area for radon before you begin.

If your test results indicate an elevated radon level, radon-resistant techniques can be inexpensively included as part of the renovation. Major renovations can change the level of radon in any home.  Test again after the work is completed.

You should also test your home again after it is fixed to be sure that radon levels have been reduced. If your living patterns change and you begin occupying a lower level of your home (such as a basement) you should re-test your home on that level. In addition, it is a good idea to re-test your home sometime in the future to be sure radon levels remain low.

c. Selecting a Radon-Reduction (Mitigation) Contractor

Select a qualified radon-reduction contractor to reduce the radon levels in your home.  Any mitigation measures taken or system installed in your home must conform to your state's regulations.  

The EPA recommends that the mitigation contractor review the radon measurement results before beginning any radon-reduction work.  Test again after the radon mitigation work has been completed to confirm that previous elevated levels have been reduced.  

d. What can a qualified radon-reduction contractor do for you?

A qualified radon-reduction (mitigation) contractor should be able to:

• review testing guidelines and measurement results, and determine if additional measurements are needed; 
• evaluate the radon problem, and provide you with a detailed, written proposal on how radon levels will be lowered; 
• design a radon-reduction system; 
• install the system according to EPA standards, or state or local codes; and
• make sure the finished system effectively reduces radon levels to acceptable levels.

Choose a radon-mitigation contractor to fix your radon problem just as you would for any other home repair.  You may want to get more than one estimate.  Ask for and check their references.  Make sure the person you hire is qualified to install a mitigation system.  Some states regulate or certify radon-mitigation services providers.

Be aware that a potential conflict of interest exists if the same person or firm performs the testing and installs the mitigation system.  Some states may require the homeowner to sign a waiver, in such cases. Contact your state radon office for more information.

e. Radon in Water

The radon in your home's indoor air can come from two sources:  the soil and your water supply.  Compared to radon entering your home through water, radon entering your home through soil is a much larger risk.  If you've tested for radon in air and have elevated radon levels, and your water comes from a private well, have your water tested.  The devices and procedures for testing your home's water supply are different from those used for measuring radon in air.

The radon in your water supply poses an inhalation risk and an ingestion risk.  Research has shown that your risk of lung cancer from breathing radon in the air is much larger than your risk of stomach cancer from swallowing water with radon in it.  Most of your risk from radon in water comes from radon released into the air when water is used for showering and other household purposes.

Radon in your home's water is not usually a problem when its source is surface water.  Radon in water is more likely when its source is ground water, e.g., a private well or a public water supply system that uses ground water.  Some public water systems treat their water to reduce radon levels before it is delivered to your home.  If you are concerned that radon may be entering your home through the water, and your water comes from a public water supply, contact your water supplier.

If you've tested your private well and have radon in your water supply, it can be treated in one of two ways.  Point-of-entry treatment can effectively remove radon from the water before it enters your home.  Point-of-entry treatment usually employs either granular activated-carbon (GAC) filters, or aeration devices.  While GAC filters usually cost less than aeration devices, filters can collect radioactivity and may require a special method of disposal.  Point-of-use treatment devices remove radon from your water at the tap, but only treat a small portion of the water you use, e.g., the water you drink.  Point-of-use devices are not effective in reducing the risk of breathing radon released into the air from all water used in the home.

To have your San Antonio, TX home tested for radon, contact Veteran Home Inspections