Tom Gauldin May 16 1997, 12:00 am show options
Newsgroups: alt.home.repair
From: (Tom Gauldin) - Find messages by this
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Date: 1997/05/16
Subject: slate/tile floor for screen porch in N.E.
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wrote:
My favorite part of our house in Connecticut is a 14x14 screen porch off
the living room. It's screened on three sides with no doors to the
outside, just into the house. The floor is pine slats over a 2x8 box
frame. There's no realistic access to the underside. The floor & house
are about 35 years old and in great shape.

Your question comes as I have been giving personal thought to just
such an
upgrade to my own outdoor deck.

The problems you'll face are several and not just singular. First of
all, the
substrate for tile or slate must be very rigid to prevent the tile and
grout
from popping from deflection. If I were you, I'd top the existing
flooring
with at LEAST 1/2" plywood to even things out and to add more
strength. I
wouldn't fool with visqueen between the plywood and deck, since
moisture that
might reach the plywood should be permitted to get on away.

The next problem you'll face will be movement from expansion and
contraction
from both moisture and temperature. To reduce this, I would then
screw down
on 6" centers 1/2" cement board. This has virtually the same thermal
characteristics as the tile, grout and adhesive.

Once taped and filled, I'd then apply the tile or slate using standard
thinset
wetted with latex additive and would use the same additive in the
sanded
grout.

I suspect strongly that this will give you a long-lasting and
perpetually
attractive floor.

Tom
Tom Gauldin Here's to the land of the longleaf pine,
I would like to tile my outdoor deck.
My porcelain tiles are 18"x 18". What kind of plywood and other
materials should I use?
Should I use cement wonder board or only membrane on the top of the
plywood.

THANKS
Michael