I'm currently installing a 1/2 plywood sub-floor over an existing 3/4 OSB sub-floor in preparation for some prefinished hardword. I noticed that my subfloors have quite a few undulations and quickly determined some leveling/flattening needed to be done. I noticed you previously answered a question concerning finding high spots and alluded to "shimming and laying in". Could you please expand on this procedure? I currently have read that asphalt shingles are one way to flatten things out .. but there are some areas on my floor that are nearly 3/4 inch lower than others (with in a 10 sq ft area!) - that's alot of mushy shingles!
Answer:
Not only are the shingles mushy, with time they also get smelly and you sure don't want that. If you're going to shim, do it with shim shingles. They're wedge shaped and you never use one by itself, you have to use one from each side so the support is even. The only other caveate I have for you has to do with the screws you'll be using - don't put any in so they go through both layers of sub-flooring and into joists because that what squeaks are made of. You can use white chalk on the walls to mark the joists and that's all there is to that.
Courtesy of Ren Molnar, Construction Consultant at HomeFocus.com. I can also be reached at (613) 748-3003 and Home Focus – The Radio Show is broadcast live 8 to 10 A.M. (Ottawa, Ont. time) on Saturdays on www.cfra.com. In the interests of retaining credibility and in fairness to all, I cannot recommend prices, people nor companies for various projects.
