Good evening folks. This is my first time so be gentle with me. Have purchased self-adhesive vinyl squares to help give my kitchen a new look. Present flooring consists of one layer of vinyl squares over a very old layer of sheet vinyl the padding for which (and probably the vinyl as well) is asbestos-based. Needless to say I don't plan to mess with any of it. The existing surface is in pretty good shape but has some gouges and chipped areas ... some of which are 2"x3" or so. A 1/4" plywood underlayment stapled/nailed/screwed to the existing surface should give me a great working surface. Problem is that I get conflicting advise as to which plywood to use. Luan is fairly cheap (less than $11 per 4/8' sheet) but the Home Depot guy said that it will leach some kind of chemical/stain thingie up into the new flooring squares. He said to use a softer-wood underlayment (also 1/4") ... but that stuff is twice the price (and half the rigidity). The floor area is relatively large (14 4x8 sheets-worth). Any thoughts out there? Once the underlayment is selected, should it be nailed, screwed, or stapled? Thanks ever-so.

We just installed vinyl flooring but the corners are curling up! What can we do? They seemed just fine when we installed them, but within 3 days they are curling! Help