I have a screened in porch that currently has increasingly gross
outdoor carpeting on it. A dog, two kids, a sandbox, spilled
bubble-juice, and one end that gets soggy each time it rains has made
it pretty gross out there. It's now beyond the help of a steam
cleaner.

I was thinking of putting tile down out there. The subfloor is
pressure treated 3/4 plywood. It feels structurally stiffer than the
floors in the house, seems well built. I figured I'd put down cement
board over the ply, mortar those joints, and put down some one foot
square tiles with some texture to them to get traction when it's wet
out there. Any recommendations along the lines of do it or don't do
it, adhesive type, grout type, tile type? My biggest fear would be
expansion and contraction with the seasons causing cracks since the
subfloor's not in a climate controlled area.

Thanks, all.

Consider using Ditra under the tile.

I'm not positive about the outdoor application, where are you located?
But check the Schluter (manufacturer) website, I'm sure you'll find
some decent info there.

M
smcjensen wrote:
I have a screened in porch that currently has increasingly gross
outdoor carpeting on it. A dog, two kids, a sandbox, spilled
bubble-juice, and one end that gets soggy each time it rains has made
it pretty gross out there. It's now beyond the help of a steam
cleaner.

I was thinking of putting tile down out there. The subfloor is
pressure treated 3/4 plywood. It feels structurally stiffer than the
floors in the house, seems well built. I figured I'd put down cement
board over the ply, mortar those joints, and put down some one foot
square tiles with some texture to them to get traction when it's wet
out there. Any recommendations along the lines of do it or don't do
it, adhesive type, grout type, tile type? My biggest fear would be
expansion and contraction with the seasons causing cracks since the
subfloor's not in a climate controlled area.

Thanks, all.

in buffalo ny: if this is on a concrete slab allow for rising moisture
and easy snow removal. if you have kids and pets you will be avoiding
oily deck toppings. if this is a porch with a crawl space, it will be
also handled according to your climate/rainfall/drainage of the home.
in some cases a rubber roof material may be the department you seek. my
neighbor used some newfangled roll of a self-stick roof material i
would explore to see if it is needed to keep the plywood dry. subject
to your climate an extra hose spigot and a lawn sprinkler may be
desired for daily rinsing of a deck you are describing. ours is on on a
windup water shutoff timer. we have used those colorful 24" square
interlocking playrom padded rubber squares with some success except not
in winter. good luck!
browse your major concerns he
http://www.buildingscience.com/resou...r_Renovate.pdf

smcjensen wrote:
I have a screened in porch that currently has increasingly gross
outdoor carpeting on it. A dog, two kids, a sandbox, spilled
bubble-juice, and one end that gets soggy each time it rains has made
it pretty gross out there. It's now beyond the help of a steam
cleaner.

I was thinking of putting tile down out there. The subfloor is
pressure treated 3/4 plywood. It feels structurally stiffer than the
floors in the house, seems well built. I figured I'd put down cement
board over the ply, mortar those joints, and put down some one foot
square tiles with some texture to them to get traction when it's wet
out there. Any recommendations along the lines of do it or don't do
it, adhesive type, grout type, tile type? My biggest fear would be
expansion and contraction with the seasons causing cracks since the
subfloor's not in a climate controlled area.

Thanks, all.

smcjensen wrote:
I have a screened in porch that currently has increasingly gross
outdoor carpeting on it. A dog, two kids, a sandbox, spilled
bubble-juice, and one end that gets soggy each time it rains has made
it pretty gross out there. It's now beyond the help of a steam
cleaner.

I was thinking of putting tile down out there. The subfloor is
pressure treated 3/4 plywood. It feels structurally stiffer than the
floors in the house, seems well built. I figured I'd put down cement
board over the ply, mortar those joints, and put down some one foot
square tiles with some texture to them to get traction when it's wet
out there. Any recommendations along the lines of do it or don't do
it, adhesive type, grout type, tile type? My biggest fear would be
expansion and contraction with the seasons causing cracks since the
subfloor's not in a climate controlled area.

I think this may depend on your climate. Things tend to move with
freezing weather. If your climate is mild then no problem. If you are
expecting 20 below then maybe new carpet is the ticket.

Growing up we had a tile front porch, it was glazed tiles, and was
beyond hazardous in wet weather, snow and ice made it all the worse. My
Dad finally covered it wit outdoor carpet even though by then everyone
had been trained to immediately get a death grip on the porch rail and
slowly skid themselves to the door or steps depending on direction of
travel. I bring this up, mainly to bring up safety concern with
traction if snow blows into the screen porch. Granted glazed is the
worst case scenario, but any given tile is slipperier than any given
carpet.

Expansion and contraction will be your biggest enemy,
assuming you do the whole installation properly.
Any weak link in the installation will cause a failure.

Using cementboard as a backer will help the
expansion/contraction problem, but not eliminate
it. If you insist on tiling, at least use porcelain
tiles which are more dense, absorb less moisture
and are less prone to expand/contract.

There are also "flexible" thinsets available, and
when grouting it would help to not grout around
the perimeter, but use a flexible sealant to allow
the teeny bit of flexing. I've seen dozens of
buckled tile floors that lifted right up when they
expanded just 1/8" and had no where to go.

I'd have doubts about the area you said gets
flooded from time to time. The wood there may
be warped or loose.

You have a situation that requires every step to
be done correctly. It has all the elements that
cause failures: temperature extremes, over
wood framing (not a slab), old wood subfloor,
lot's of traffic/abuse potential, and you're not
an expert installer.

I'd say to get yourself some new indoor/outdoor
carpet, and when the kids grow up and move
out, do the tilework......

thetiler