Subfloor on top of slab


Old 02-29-04, 10:50 AM
Visiting Guest
Posts: n/a
Subfloor on top of slab

I am going to finish a porch (16'x20')that adjoins the main house. This porch has a slab floor that is approx 5 inches lower than the main house (which also sits on a slab). I plan on building up the porch floor with 2x4 joists shimmed to the slab. What should my subfloor system be prior to laying tile? Also, what would be the best way to insulate this space?

Thanks for your help
Sponsored Links
Old 02-29-04, 11:12 AM
Visiting Guest
Posts: n/a
has this porch been enclosed ? i assume so ,the subfllor needs to be 3/4 cdx plywood with a 1/2 layer of durock for the tile to sit on space these sleepers at 16" intervals and shoot to the floor.
If it were me i would use the syrofoam insulation that comes in 4 x 8 sheets and cut them down to fit in between.

Get you're tile and see how thick it is and allow the thickness of a peice of cardboard for the thinset and figure your floor thickness according to that.

If this has not been enclosed then we need to do things a little different
Old 02-29-04, 12:47 PM
Visiting Guest
Posts: n/a
Yes, this is an enclosed porch, with 3' fnd walls, previously unheated.
Thanks for the reply. I was hoping 1 layer of 3/4" would be adequate.
Old 02-29-04, 09:46 PM
Visiting Guest
Posts: n/a
Might not be a bad idea to put down a 6mil poly moisture/vapor barier on top of slab under the rest of your material. Cheap insurance against moisture problems. :-)

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: