Advanced Radon Measurement Service Provider Course
I inspected the crawlspace on a 40 year old home. The crawlspace had no vapor barriers over the bare soil, and there were numerous areas noted that lead to the upper living areas that needed to be sealed. According to the owner of the home, the home had never been tested for radon, though the area of the state where it is located has had a history of radon concentrations. I recommended that the owner have a radon test performed, and that if it came back with evidence of radon being present, that steps be made to mitigate the crawlspace for the safety of he and his family.
Inspected properties may be in areas where soil contaminants are prevalent. Generally, contaminants are the result of man-made chemicals that have come in contact with clean soil. Other sources include, but are not limited to, wastes that leach from landfills, livestock manure, hazardous waste dumping, old mining operations, and septic systems.
Contaminated particles pollute the soil by attaching themselves to the soil itself, or by residing in the spaces between the soil particles. The three most widespread pollutants are lead, arsenic, and cadmium. These are heavy metals that, though now banned from use, still remain in the soil due to paint chip residue, old wooden structures that was preserved by the use of arsenic, and the burning of fossil fuels which releases the byproduct cadmium.
One of the greatest hazards from contaminated soil is drinking water from underground water wells and aquifers. Cancer, neural disorders, reproductive disorders, and birth defects can all result from drinking contaminated water.
The only sure way to tell if soil is contaminated is to sample the soil and have a certified laboratory test it. Regardless, inspectors should recommend further evaluation by a professional if contaminated soil is suspected.
This is a picture of a passive radon reduction system in a house. The vent pipe ran from the sump pit through the roof. The pipe appeared to be installed correctly.
Here was a inspection I did a while back. While checking over the roof, I found that the owner decided to save money by doing the shingle job himself. I should explain this was a presale inspection, but as you can see he did not feel the need for flashing. I explained to my client how important it is to have flashing in this area, one being covering up the exposed nails. He had just done the shingle job to help sell the house, but I feel he may have just made, at least this area, no improvement when he tried to fix it. It is hard to see from this picture, but the sheathing was buckling under the new shingles, which I suggested he should have replaced also. I could not access any attic access at all in this home as to see if there was any leaking or not, but I marked as a defect.
Lead Facts for Inspectors.
I found it interesting that before 1955 paint had 50 percent lead in it. Even when they changed the law in 1970 it still contained .06 percent lead. In 1978 they finally banned lead in paint completely. There is no safe threshold of lead in paint. It was also used in plumbing and gasoline. Children are more vulnerable the adults. Blood test can be done to test for lead poisoning. When in plumbing, boiling the water will not remove any of the lead from the water. Water used for drinking, should let water run for 15 to 30 seconds before drinking and only use the cold water, for hot water actually absorbs more lead then cold. So as a home inspector it is important to recognize the health issues that lead can cause and to check for the possibility of it still in older homes.
This image is of a crawlspace that was previously straight gravel. The owners had originally reasoned that sealing over the gravel with concrete was just for ease of use as a storage place, but conversations with their contractor also led them to install 8-mil polyethylene sheeting under the concrete as a soil-gas barrier. They did not have a radon test done prior to the installation of the concrete.
Inspecting a Crawl Space…
This home was built in 1999.Inspection of the Crawl Space resulted in me finding no Radon Vent Pipe present and there was no soil gas retarder present.I recommend a Radon Test be performed and that a 6-mil polyethylene or equivalent flexible sheeting material be installed.There was a coarse gravel present that appeared to be adequate.
I found it interesting about the conflict of interest exists if the same person or company performs the radon test and installs the radon mitigation system and that some states require the homeowner to sign a waiver,in such cases.I guess I’ll be checking with my state radon office to see if this affects me.
As the title suggests, this is an article that gives an overview of radon gas to a consumer. As such, it does not go into any of the physics behind the radioactive decay of uranium or specifics of how radon testing or mitigation is performed, but focuses on the health risks and what options a consumer would have in detecting and mitigating radon. It is presented in the widely used FAQ format, which makes it easier for a consumer to understand. I find it to be an excellent starting point to talk to consumers about radon.
There are new building standards and codes that can reduce or eliminate radon levels in a home. Many builders are now installing radon depressurization systems to eliminate future problems. The power vented active systems are most effective.
The image is a radon gas detector. This unit is both a short and long term device designed to be plugged into an outlet or other dc power source. It is regulated and equipped with with an alarm that chirps when the reading is ( 4.0 pCi/l ) which is the level that is suggested by the EPA to be mitigated lower. Radon gas is invisible to the eye and also tasteless and odorless and is a known cause of lung cancer.
Radon gas or the radioactive decay can get into the ground water supply. If a home tests high for radon and has a well water source that source should be tested as well. If radon is to be mitigated from water there are two methods/devices. Aeration and/or granular activated carbon should be used to treat the water before it enters the home.
Here is a crawlspace of a home I recently inspected here in Colorado. The client did not order a radon inspection. You can see the soil has no vapor barrier of any kind. This area of Colorado is in Radon Zone 1.
As a home inspector in Colorado, it is my ethical duty to inform all of my clients that all of Colorado is in Radon Zone 1. This means that the entire state has a predicted average indoor screening level greater than 4pCi/L. And that if the home they are buying doesn’t have a radon mitigation system already installed then the least they should do is have a radon test done to be sure the home they are buying or selling doesn’t have elevated levels of radon.
Radon and a Crawl Space
Many homes have areas of open soil which are often refereed to as crawl spaces. These areas can be a major entry point for radon gas and a breeding ground for a host of other indoor air quality problems. So sealing of these areas is always advisable with either cement or a durable membrane. But of course this is not always possible due to limited working room or perhaps budget.
For sealing crawlspaces, Use 6 mil or 12 mil Dura-Skrim vapor barrier that consists of two sheets of high strength polyethylene film laminated together with a third layer of molten polyethylene with diamond reinforced skrim. Basically this translates into English as a very durable plastic.
Make sure all seems are sealed and the edge of the vapor barrier is sealed . I recommend getting a radon contractor to do the job so you get the right material and venting.
Here are a couple ways to get bats out of your home or building. This should be done at night when the leave there nesting area.
• The entry point for the bats should be identified. Holes as small a human thumb are large enough for some bats to squeeze through. The homeowner can seal off most of these holes with caulk, leaving one hole intact for resident bats to exit at night.
• The homeowner can then plug this hole at night so that bats cannot return to the house. Alternatively, the homeowner can install a one-way “check-valve” from wire mesh that will allow bats to exit the house but not allow them to return.
• “Bat houses,” which can be constructed or purchased, can be placed next to the house during bat removal to provide bats with an attractive alternative to the house.
If you don’t want to mess with them then I would recommend calling a local pest control company or animal control.
Bats can transmit dangerous diseases to humans, and inspectors and homeowners should be wary of bat infestations.
A common area for radon to enter a home is through the floor to wall joint in a basement. Other areas radon can enter are cracks and control joints. In addition radon can enter a sump hole or around other openings in the floor like around plumbing.
Since most radon enters the home from the ground below it, a crawlspace is an especially susceptible entry location into the home. If it is an older home like the one pictured there is a good chance that there would be no 6 mil vapor barrier installed or passive venting as a means to limit the infiltration of radon into the home. Making sure the vents are opened allowing air to exit the crawlspace area could help alleviate some of the buildup of radon gas in the area. You do however need to be careful to protect any plumbing pipes that are next to these vents in cold climates from freezing.
There are new building standards and codes that can reduce or eliminate radon levels in a home. Many builders are now installing radon depressurization systems to eliminate future problems. The power vented active systems are most effective.
