Basement Floor Paint and Radon

[marrt]

I bought a new “spec. home” from a builder about a year ago. At that time, I had the house checked for Radon. The house had a Radon reading that was ten times the recommended level so I had a fan installed that pulls air from below the basement slab. I’m now in the process of finishing the basement and wonder if I should paint the floor, as further/extra protection, before I put carpet down. There is a product on the market called “Radon Seal” that’s specifically for basement floor use but it’s very expensive and can only be bought directly from the manufacturer. Dry Lok also offers some protection but I don’t think its recommended for floors. Any opinions?

 

[Rch]

marrt, before you buy that expensive paint try this. Caulk around the edge of the floor where it has pulled away from the wall with silicone. Second, caulk around any perforations through the floor such as transfer pits, sump pumps, water pipes, drain connections (especially future bathtub or shower drains where you see the subslab aggragete- use GreatStuff foam, you can dig it out later if you install something) Most importantlly, seal the sump pump lid with a vent to the outside. This is easier than it sounds. Drill a small hole in the side of the disharge pipe(1/8 " or less) below the sump pump lid but above the water level. The back flow is trivial and this relieves any pressurization. You then seal the lid around the edge and discharge pipe. Get the kind of sump pump that has 2 cords running to the pump. One plug plugs into the back of the other plug which then plugs into the recepticle. To test the pump you just plug the piggy-backed plug directly into the recepticle and the pump should work- no disturbing your seal job.
Prospectively a small transfer pit (for sewage) is used instead of a sump pump basin because it is set-up already to seal the lid and a couple of perforations.
Recheck your air radon levels. If still over 4 picocurries/liter then you've got to vent the slab and maybe add an electric vent to actively vent the sump pump . Also the check radon level in the water( if well water). Exhaust fans strategically timed when showering or a dishwasher running can make a big difference. Placement of devices to sample air radon levels have to take this in consideration. This could be a factor. Our local hardware sells kits for this. Radon testing and mitigation is part of the real estate deal here. If there is granite below you, especially if you have a well, radon has to be considered.
radon info Punch in"radon" in the search box

 

[tdenny]

marrt,

Dry-lok is't recommended for floors but I have used it for them and as long as you are goin to put something over the concrete (carpet) then you wouldn't have any problems. The problems occur when you are walking on the floor or getting it wet, etc. This product is quite a bit cheaper than the Radon stuff you have researched. I'm not sure whether or not the Dry-lok will help with radon problems though? /forums/images/graemlins/confused.gif