DIYbanter - View Single Post

writes:

But if it is
sealed and hosed off occasionally is that going to be a problem?

Look, it has a water absorption of quite a few percent. *Anything*
waterborne on top of it will get into it and stay there, locked in the
spongy matrix forever. That means tannins and mildew and whatever else
your outdoor surfaces collect.

Sealed? A hair-thin layer of acrylic will only slow down contamination.
It's not a hermetic seal. Why do you think people learned to hate
chattahoochie==and that was 1/2 inch of epoxy "sealer"?

Hosing it off? How will having it clean once in a while change that it
is dirty the rest of the time?

Why do you think outdoor grout gets dingy? It has less WA than
travertine.

I'm not saying weathered/dingy travertine isn't OK. It just isn't at
all what it looks like when new.

Why not test it first? Buy a tile or two at the home improvement store.
Apply sealer to one if you like. Put these tiles out on your back porch
with some wet leaves and dirt on it for a month or two. Hose it off.
Scrub it. See what you get.

If you have access to an accurate scale, you can do your own lab
testing. Bake a tile dry and weigh it. Soak it in a bucket of water
for a few days, and weigh it again. Divide the mass difference by the
volume (in metric) to get the percent of water absorption. If it is
more than about 1/2 percent, you're gonna have problems with this stuff
outdoors. I'd bet you'll get 3 or 4 percent, or more.