Replies

1. 
   surujunah | Sep 09, 2009 03:51am | #1

   i'd say that thinset mortar would be a good bond for the plywood. make sure and get the polymer modified stuff to allow for more flexibility. and use a marine grade plywood so the glues are of higher quality. the paint is where i would be concerned, however. movement and heat can't be too kind to it. maybe a special porch and floor enamel would be better? good luck.

2. 
   Jeff_Clarke | Sep 09, 2009 08:03am | #2

   I'd say that this is a really bad idea and would try to talk them out of it.

   Jeff

3. 
   TomW | Sep 09, 2009 09:17am | #3

   I'd face nail it down, fill the nail holes and paint it. If the system is designed well the temps won't be all that high and you wil;l have less movement with plywood than with a solid  wood floor. I did 7" wide pine over radiant heat and have had no problems with it.

1. 
   Piffin | Sep 09, 2009 02:36pm | #4

   same here.Normally I would use glue too, but 99.9% of people will be unhappy with this look after a year or two and will want to tear it up, so the nails is good. 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

4. 
   wane | Sep 09, 2009 03:04pm | #5

   there is a laminate around just like that, 12" wide, couple of different colors, snap, click ... plus I'd hate to hit the heating with a fastener ..

5. 
   Clewless1 | Sep 09, 2009 04:22pm | #6

   Plywood should be really thermally stable relative to many other floor materials (e.g. solid wood). What are you doing w/ the edges of the plywood? That could be an area of problem from a finish and user standpoint (i.e. slivers). Maybe just knock the edge off w/ e.g. sander or planer? After it's painted, it will be OK?

6. 
   Danno | Sep 09, 2009 07:49pm | #7

   I'd worry about all those splintery edges, esp. when cutting plywood into 12" strips. What about just routing fairly shallow grooves to make the "strips"?