The Radon Debacle

The Radon Debacle


The Radon Debacle


On a recent home inspection the radon test came back high at 7.3 pCi/L (picocuries of radon per liter of air.) The EPA has set a national action level of 4 pCi/L (picocuries of radon per liter of air) for indoor air. The average indoor radon level is estimated to be about 1.3 pCi/L, and about 0.4 pCi/L of radon is normally found in the outside air. The property seller had the home tested for radon when she bought the house three years ago. The level at that time was 1.6pCi/L, well within the acceptable range for radon in the air. So what happened? The home-owner had an indoor foundation drain system installed. The system consisted of a series of floor drains around the perimeter of the inside of the basement. Radon that was trapped below the floor was now released into the environment. Additionally, new windows, insulation and a ridge vent were installed along with bathroom exhaust fans as per the recommendation on her last home inspection. This increased the energy efficiency of the home but created a high negative air pressure area in the living space. The exhaust fans and ventilation system were actually “drawing” air out of the basement and subsequently radon was being pulled out of the ground and into the living space. Before the radon test came back I noted a secondary and potentially even more dangerous issue. There is approximately 250 gallons of home heating oil in the oil tank located directly over a floor drain. A drain tied to a sump pump that discharges to the front yard right in front of a storm drain. Can you imagine if that tank ever leaked and all that oil was pumped outside? A radon mitigation system works by soil suction and pulls radon from beneath the house and vents it to the exterior. In order for that to work, the new foundation drain system will have to be filled in with concrete. That solves the oil into the drain scenario but leaves her with the original problem of water in the basement. Recommendations: Fix the gutters and drainpipes along with improvements to yard grading. Install flashing behind the gutters to keep them from leaking and extend the drainpipes three to ten ft. away from the house. Slope the yard significantly away from the foundation and if necessary install a curtain drain around the exterior of the home. Fill in the floor drains and install a radon mitigation system. Conclusions: Everyone did their respective jobs properly. The windows, insulation, ventilation system, exhaust fans, and foundation system were all done professionally. But the house needs to be treated as a whole unit. If you change one system in the home it could affect other systems. In this case a floor drain led to radon problems and a potentially disastrous oil spill. The foundation drain installer probably knows nothing about radon and most likely didn’t even give a thought to the oil tank. The energy efficiency team that did the windows, insulation and ventilation systems did not realize that the increased “tightness” of the home could lead to increased radon levels. So who is supposed to know how the home works as a system? A really good Home Inspector does. The next time you plan a major renovation, consult with a professional Home Inspector to make sure the systems you are installing are working in harmony with one another. Photo of oil tank near floor drain
 oil tank leak



The Radon Debacle

Why are my floors crooked?


Why are my floors crooked?

The one word answer would be water. Water is dripping behind the gutters causing compaction of the soil and the eventual sinking of the foundation. The more water that collects in one area, the more the foundation sinks in that area leading to 45 degree foundation cracks. This compression of the soil also leads to reverse yard grading adding even more water to the foundation perimeter. The center of the home where the columns and beam are located are not subjected to this soil compaction, and consequently do not sink. The overall effect is the center of the house ends up higher than the sinking perimeter causing the uneven floor problem. Undersized beams and joists and over spanned support columns can also add to the problem.

How to fix this problem!

  1. Make sure to add gutter flashing. Flashing is tucked up under the roofing drip edge and over the back lip of the gutter. Also extend drainpipes as far away from the foundation as possible.
  2. Re-grade your yard, that is, treat your yard like your roof and slope the yard and water away from the house.
  3. Cut back overhanging tree branches to limit moss accumulation on the roof and to encourage solar drying.
  4. Follow the 18” rule.

The 18” rule!

One, the roof overhang or soffit area of the house should be 18.”This keeps water from splashing back on the siding

Two the distance between ground cover and siding should be 18.” Together with the roof overhang this helps to prevent water from splashing up on the siding causing wood decay and helps to prevent the foundation from sinking and causing bowed floors.

Three, the distance between the siding and fully grown shrubs should be 18”to allow for solar drying. You should be able to walk between your house and fully grown shrubs.

Four, the distance between a finished basement wall and the interior of the foundation wall should be 18” to allow for natural ventilation and drying of the foundation wall.This also gives you an opportunity to walk behind your basement walls and inspect the foundation.

Following the 18” rule could drastically reduce problems of wood rot, mold growth, foundation sinking and wood boring insect damage.


The Radon Debacle

A deleaded house


Home Inspection tips from D&M Home Inspections. A deleaded house does not always mean a lead free house. Lead can almost always be found on, Exterior: Basement windows, porch ceilings and columns, exposed trim at old storm window locations and the soil surrounding the home. Interior; Tops of doors, cabinets, basement staircases and basement windows. Also, Just because lead paint was no longer produced after 1978, doesn’t mean people stopped using it in 1978. If you are purchasing a home and are concerned with lead paint have all surfaces and soil tested.


The Radon Debacle

Should I have my house tested for radon.


If you are having a home inspection, you should always test for radon. If you already own a home and you have never tested for radon, test kits are available in most hardware stores. Radon is the second leading cause of lung cancer in America (behind cigarettes)


The Radon Debacle

Read The Label


If You Are Painting

— Try to use low or zero VOC paints.

— A John Hopkins University study found more than 300 toxic chemicals and 150 carcinogens are present in paint.

— They include acetone, ammonia, benzene, formaldehyde, lead, pentachlorophenol, cadmium, and xylene.

If You Are Carpeting

— Use 100% Wool or other natural fiber organic carpet.

— Use carpet padding with jute or felt.

— Regular carpet can have hundreds of different chemicals including formaldehyde, 4-phenylcylohexene, styrene, toluene, benzene, xylene, pesticides, and anti-fungicides.

— Formaldehyde is in the glue that holds the different color scraps of carpet padding foam together.

— There is more formaldehyde in the padding than in the carpet itself.

If You Are Adding Cabinets

— One of the biggest sources of chemical pollution indoors is new cabinets.

— The biggest release of formaldehyde from cabinets happens in the first six months. It can take up to ten years for cabinets to finish emitting formaldehyde.

— Use real wood cabinets.

— Formaldehyde is used in construction because it is a good anti-microbial.

— Just for fun, look up the correlation between Aspartame, and Formaldehyde.

Don’t Mask the Mold Smell With Fragrance

— Are you using a “plug in” to cover up mold odor? As many as 600 separate chemicals may be used in a single fragrance formula.

— The most common ingredients in fragrance are toluene, formaldehyde, acetone, benzene, and methyl chloride.

— The bulk of chemicals in fragrances are petro-chemicals similar to gasoline.

— The chemicals in fragrance are neurotoxins that suppress the immune system

How Safe Is Your Lawn?

— Of the thirty-four most commonly used lawn chemicals, eleven cause cancer, twenty cause nervous system poisoning, nine cause birth defects; and 30 cause skin irritation.

— Pesticides attach to the bottom of shoes and are tracked into the house. Since pets and children spend more time in contact with floors, carpets and other dusty surfaces, they have potentially more exposure. (Bong,Jennifer-Children at Risk)