I read with interest the article on uncoupling layers in this month’s FHB. The stuff looks expensive, although I haven’t priced it. I’m wondering if I’d be just as well off to screw/glue a layer of 1/2″ ply over the existing 5/8″. Joists are 2×10, 16″ o.c. Span is 8′ and less. Thoughts?
Scott.
Replies
Adding a layer of plywood may (or may not) add some stiffness to your floor, depending on how stiff your floor already is, and on other factors.
But it will not accomplish the same purpose as the ditra, which uncouples the layers.
The added stiffness will help prevent cracks that are related to floor deflection. The uncoupling will help prevent cracks that are related to lateral movement (from expansion and the like).
Unless you're the lead dog, the view just never changes.
The 2 X 10 on 16 OC with 8 foot span is fine, but your problem is the sheathing. You won't bounce much at the joists, but you certainly will inbetween them. This is why I like 1 1/8" T&G for all floors, all spacing.
Adding thickness to your existing floor will work. I would definitly use plenty of subfloor adhesive between the sheets- this will help simulate a homogenous thickness of plywood. Be sure to use ring-shank nails.
Jim
I can buy the Ditra at my local tile store for about $1.40/sf. Consiodring the ease of installation, the thinness comapred to another layer of ply, and the safety it adds, it's cheap insurance.
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt