demolitionhealth-and-safetyleadsafety
I am under going demolition work in pre-1978 building. I have paint chip samples sent away to determine ppm of lead. At what levels are contractors required to wear hazmat suits and respirators?
Is there some summary document that outlines the EPA guidelines?
I gave a pretty detailed answer on radon mitigation systems in a related question. Rather than repeat myself, I suggest that you read that and follow the links, particularly the EPA's guide on radon mitigation for home buyers.
Radon levels outdoors are pretty much always going to be zero. It's only enclosed spaces you need to worry about.
As long as you can get a radon system installed without significantly destroying the home, and the radon levels aren't insanely high (100+ pCi/L), radon is not the end of the world. Tell the seller to pay for a radon contractor, or have them knock a few thousand off the selling price and hire your own guy. I would suggest getting a bid from a reputable radon contractor in the area so you know how much is reasonable for the sellers to concede. Make sure you also factor in the price of someone doing a re-test on the radon levels!
Non PT wood will be fine.
I would build a 32x22" frame out of 2x4's but I would put a 3/4" square notch around the inside diameter of the frame and set the filter into that notch. That will give you a nice seal for the filter but prevent it from falling through. If necessary, add one or two cross braces across the inside of the frame cut to the depth of the notch so the filter has extra support.
Best Answer
The magic words you want are "RRP", the EPA Renovation, Repair and Painting rules. For a simple residential demolition that's all you need. For details see http://www2.epa.gov/lead/renovation-repair-and-painting-program
Homeowners can take the RRP certification course (I did), but in most cases you'll want to ask the contractor for their RRP certification number, and ensure that the certified renovator is on site during the work. Every certified renovator is also a certified trainer, authorized to train and supervise the workers at a particular job site.
The level of lead in the paint does not matter at all under RRP rules. And the hazard depends not on the level of lead, but rather the work practices used. Sanding without a HEPA vacuum, for example, can put a huge amount of lead in the air even if the paint is relatively benign.
Note the gold standard for lead testing is not paint chip analysis, but rather XRF testing. By investing in XRF testing you'll identify areas of the demolition that don't have lead at all, and thus don't need all that plastic, tape and other waste generated.