When grouting tile, how clean do the joints have to be? IE...how much adhesive has to be cleaned out before?

Question

Laid some tile and it is time to grout. How much of the thinset has to be out of the joints? Does it have to be completely clean or can it be just knocked out fairly well...?

Answer 1

The depth of the thinset in your grout joints should not exceed 1/3 the depth of the tile.

Othewise, you'll get shading in your grout joints.

Answer 2

Sensible has the first valid clue. You shouldn't have excess mortar pushing up in the grout lines to any great degree. Installing the tile might suggest modest pressure to set them, but not so aggressive that you squeeze the mortar out of shape and out the grout joints.

Removal immediately isn't a major issue though. Just use the + shaped spacers to oull out excess and wipe while the mortar is still wet.

I have however, in the past and depending on the job, put enough mortar down, with a 1/4 inch tooh notched, flat blade knife, to create a situation where the mortar also became the grout. Certainly that would be specific situations where the tile color and dry thinset closely matched, or it was an exterior installation where the customer had no real grout color preference.

Steven Wolf

I'm curious to know if you're asking this Q "after" the fact?

Answer 3

If the thinset was applied with the proper notched trowel, you should not need to clean out the joints. If something happened that a few clumps are near the top of the tile joints, then knock it down and remove loose thinset for good adhesion of the grout.

Answer 4

Just knock it out fairly well. Must have used a bit much putting the tile in. Then fill as you would normally. Should do the trick. It is very forgiving.

Answer 5

It sounds like you don't need to be doing this call a handyman

Answer 6

It has to be fairly clean to adhere.