Using old grout.

[dougfollett]

I have been maintaining a friends tile floor. It wasn't a first rate job to begin with but it was adequate. About once every three months he has me come over and patch where the grout has cracked and fallen out. I have been using the bag of grout that he had left over from the original installation. I would go out and buy more but it was a some what unusual pink color. What I have been finding lately is that the grout doesn't set up poroperly. It looks OK but it is soft and can be dug out easily with a knife. Does grout go bad sitting in the bag? It has clumped up some.

[hallerb]

yeah its bad, you might check with a tile store to match it colore wise, or remove all the old grout and start over anew.

is the trouble a poor subfloor thats moving even a little? is the tile on concrete board?

if the sub floor isnt solid nothing you do will help:(

[dougfollett]

I know what the problem with the original tile job is, the underlayment is flexing and causing the original grout to crack. That isn't may main concern as I can continue to re grout the broken stuff from time to time. It isn't that bad, maybe twice a year I have to chisle a small spot out and replace it with new. My problem is that the original bag of unused grout seems to have gone bad. Does unused grout go bad? I mix up a little pot, let it sit for about ten minutes and then apply it. The next week it can be dug out from between the tiles with a car key. It apears to never have set up although it is hard and dry there is no strength to it. It's more like plaster of parris but softer. I guess I should just break down and go looking for some new grout but this stuf is pink and probably hard to find. Also I can't believe grout has an experation date but I guess it does. This stuff has begun to clump and I have to sift it before mixing to get the lumps out.

[Oren]

I can't use a partial bag that is only 6-9 months old. Seems like it takes on moisture and I live in the desert.

Did you follow the directions on the bag? I've seen directions to mix, let sit and mix one more time before application.

A bag of cement will harden over time.... Any good tile place will have color sticks to let you pick a grout color. I put in some teal green some time ago - yes the left over stiffened up and is disposed of.

Oren "My doctor says I have a malformed public-duty gland and a natural deficiency in moral fiber, and that I am therefore excused from saving Universes."

[Doug Miller]

In article , [e-mail] wrote: [snip]

Yes, it does go bad. Grout cures because it undergoes a chemical reaction with the water that you mix into the powder. (The same is true of plaster of Paris, mortar, cement, plaster, etc.) It undergoes the same chemical reaction, albeit at a slower pace, with water *vapor* that is present in the air. That reaction happens only once -- in other words, after the grout has been exposed to humidity for any length of time, it's no good any more. There's no practical way to rescue the grout you have now; the best you can do is replace it. To prevent the problem from recurring, store the unused grout in an airtight container. That won't make it last forever, but it will extend the shelf life considerably.

[Elizabeth]

replying to hallerb, Elizabeth wrote: Why would Part of my grout Flake when some is not?