Radon Mitigation

[Rhaine86]

Hi all- I have several questions and concerns relating to fixing a radon problem in my house. Any help or advice would be appreciated...

My husband and I have done two short term radon tests, both of which indicate the need for mitigation. We have been told the average price of a radon system is somewhere between 1200-1500 dollars. I asked the company who gave me this rough estimate to tell me what they could about installing a fan (??) and was told that if I had a vent pipe already in place you can just add a fan to it and usually solve the problem that way. She explained what to look for etc. Well, I have found the black fat pvc pipe she spoke of in our basement- but it doesn't go through to the roof and out like she said. So I'm thinking this is just the "stub". It's off in a corner away from where a bathroom or any other plumbing should be. It sticks up about 2 feet from the ground. So--- does this mean we still will need to spend the 1500 dollars to have someone put in a system??? Or would it mean less of a problem (and expense) because they can just extend the pipe up through the ceiling and add a fan??? I guess I'm just going to have to ask them to come out and give me an estimate. We just don't have 1500 dollars laying around that we are dying to spend on this....any thoughts??

[Rhaine86]

Just a quick addition here-

My husband got home and looked at the basement (which is unfinished btw) with me. He thinks that the black pipe that is near the bathroom and runs up into the ceiling and out the roof is the vent pipe. It is definitely hollow, and it's not for water or anything (those are small copper pipes nearby)- but it is very near where the toilet would be as evidenced by the short black pvc pipe (capped) that sits in front of it about 1 1/2ft. The pipe he is looking at actually starts as two running parallel from the cement (About a foot apart) and then one connects up with the other which then goes to the ceiling.

If this is the pipe I'm guessing it was put in that area as it's definitely going to be a place where a wall will be-- so it won't cause any problems when the basement is finished. But am I missing something in the bathroom?? Could this be a bathroom pipe somehow?

And what could that other pipe that sticks up out of the ground be for?????

[LazyPup]

I just spent the better part of the day researching a similar radon queston for another forum I participate in.

If you have a vent from under the foundation with an open termination in the basement the installation was obvously not completed during construction and in its present state it is actually adding to the Radon problem in your house.

Radon is a radioactive gas that is naturally present in the soil in some locations.

Physical properties of radon:

Radon is the heaviest know gas, therefore it will concentrate in low places such as in the basement at standard atmospheric pressure.

In its natural state the concentration of radon in air is 1 molecule of radon in 100,000,000,000,000,000,000 molecules of air. (1 x 10 to the 21 power).

Radon does have an odor, however in its natural state the concentration of radon is well below the ability of the human olefactory senses (the nose) to detect it.

Subterranean air pressures are slightly greater than atmospheric air pressure, therefore radon laden subterranean air naturally rises through the soil to the surface where it dissipates into the atmospher e without notice.

The rising radon laden subterranean air can become trapped under a foundation slab, where it will eventually permeat through cracks, crevices or any openings in the foundation and collect near the floor in basements. The Radon gas can then be distributed through the structure by the natural convenction currents of air in the structure.

In areas that are know to have higher concentrations of radon gas in the soil the EPA suggests radon abatement construction techniques. Basically a 4" to 6" layer of crushed gravel is compacted, then an impermiable membrane (6 mil polyethelene plastic) is laid over the gravel. One or more 4" PVC pipes are then installed from the gravel layer to a point above grade and outside the structure. As radon laden subterranean air gets into the gravel layer it then migrates laterally under the membrane until it reaches the vent and can be dissipated. In a worst case scenario a powered exhaust fan can be installed on the vent lines to suck the radon from under the slab and vent it out.

From your description it sounds as if the subfloor work may have been done, but they failed to complete the stack out to atmosphere. If that is the case you presently have the radon laden air venting into the basement which would enhance the problem. The first step would be to complete the stack out, then thoroughly ventilate the basement before conducting additional radon level testing.

According to the EPA for homes that do not have the underfloor venting there are some very effective retofit but relatively inexpensive measures that you can take to reduce radon.

1. Seal all cracks and crevices in the foundation, both basement floor and walls. In most instances painting with an oil base paint or concrete sealer should be sufficient.

2.Seal all openings through the foundation wall where water, drainage, electrial or other utilities enter the structure. (The plumbing codes require all such openings to be sealed with expansion foam or other suitable methods.)

3. Open earth crawl spaces should be covered with an impermialbe membrane (6 mil polyethelene plastic) and at least one open vent to atmosphere. If the outer perimeter of the crawspace is open that should be sufficient. If the outer edge of the earth crawlspace is concealed you can install a 4' vent pipe from under the membrane to open atmosphere.

[MockSwede]

Not sure if you have had any replies. Lots of good information on web. I've purchased air radon check kits from www.airchek.com and they have more information, too. It's a start and, by no means, the only place to look for info.

You are NOT supposed to hook up a radon abatement system to the DWV venting system for the plumbing of the house. That's plumbing CODE and radon abatement code, when there is one. May be different in different jurisdictions.

Radon vent pipe does not have to go up and out through roof; can go out through side wall of house, just needs to be at least 10 feet from then nearest window/door/operable opening from inside to outside (so radon doesn't just blow back inside).

The fans available for the venting of radon actually hook up to the same while schedule 40 pipe used for plumbing houses. The difference is that they are sealed air-tight with gaskets. Just have to size up pipes to fix a 6 inch diameter on the van assembly with some rubber boot-style (Fernco) piping size connectors/adaptors. Do want to be able to replace or service unit so do not solvent weld fan casing into rest of radon vent piping.

I would suspect that these two pipes are NOT usable for radon abatement system. They are probably both waste or vent pipes running out of the house to the storm drain (if from cellar perimeter drains or from rain downspouts) or to sewer (if from household 'appliances' like showers and sinks and toilets and washing machines, etc).

If it were a radon abatement pipe it would be coming up out of the middle of the poured concrete floor - perpendicular to the floor. It should be in the middle so as to provide equal reach to the area of the floor when fan used for subslab suction radon gas abatement.

The fan unit I have is about 16 inches diameter at its widest and about 12 inches tall. Will NOT fit inside a normal 2x4 interior wall.

I installed my system myself with plumbing fittings locally available and purchased a (less expensive) refurbished fan unit ordered over internet. (If I remember correctly it was about $120.)

If you want more particular information, get ahold of me. Also looks like other posting has good information, too.

Do want to get levels below 4 in lowest inhabited space.

[Rhaine86]

Thanks for the great responses.

MockSwede, I think I may have explained the pipe a bit poorly. There are two black pipes that are parallel (to eachother) that come straight up from the cement. One connects up with the other a few feet up. These pipes are pretty centrally located in the basement. They're hollow and don't seem to be used for anything right now. We've located the sewage pipe for the bathroom upstairs and it is totally separate. The water pipes are also separate from it. We've turned on all the fans and located where they exit from. the washer/dryer are on a separate wall on the same level and do not use it either.

I happen to know a professional home inspector that frequents my place of work and I asked him about this pipe. He suggested that I call a company in my area that does radon and mold testing. They give free quotes on putting in a fan to activate the passive system (most houses in my area at least have vent pipes he said because of the high occurrence of radon in the area). And if it turns out to be a vent pipe, at least we'll know for sure and then we can either attempt to put one in ourselves, or if they have a good price- let them do it.

Thanks for the responses. They were very helpful. I'm feeling like I may be an amateur radon expert by the time I get through with all this!!!

[Rhaine86]

Well I'm replying again to this post. I'm feeling a bit disheartened. I *finally* called someone to come out and take a look at my basement to let me know for sure if I have what is needed to attach a fan to. After stumbling across some websites I read that you have a DWV (drain waste vent) pipe for toilets etc. and now I'm thinking crap-- that's what these pipes are for. That's why they are so near where the toilet would go. I guess I didn't really understand what you were saying MockSwede, because you seemed to clarify this all for me months ago! The pipes say "NSF-DWV" on them- I was hoping it meant "not suitable for- drain waste vent". Unfortunately, that's not it (Darn!!). So until this guy comes out to look at the basement (he's supposed to come today), I will continue to feel glum and admittedly sorry for myself because I think this is really going to cost me. I want to get this taken care of, but then again, I don't *really* want to know how much I'm going to have to spend. It just makes me angry thinking that the previous owner (who was the builder for the neighborhood), may have never bothered to put in a vent pipe in the case that a fan was needed. Radon is very common in this part of the U.S. and apparently in the "newer" homes (what year determines that?!) it is pretty standard to put the pipe in just in case. I will post when I find out for sure what the status is.

[LazyPup]

There is no national code requirement to install the piped system, that is simply an EPA recommendation.

There are lots of dooms day profits running around the country milking the public with scare tactics to get you to invest in expensive flim flam schemes but according to the EPA if you do not have the underfloor venting system all you need to do is paint the floor and all the basement walls with an oil base paint, then seal any and all openings through the floor or basement walls.

[SSN596]

NSF means National Sanitatin Foundation.....just another rating on those pipes, along with DWV. This is the type of pipe which would be used in a radon mitigation system, but without seeing it, it does sound from your description that it is piping for a future bathroom.

I hope by now you have settled the issues. Please let us know how it worked out.