Questions after a test-run grout replacement

Question

I have very little experience with this sort of thing, so after reading and watching you-tube videos I attempted a test patch - a 3 tile wide, 1.5 tile deep section (these are 12" floor tiles). And now, I have questions…

1. Removing the old grout

I purchased a hand grout saw for the test patch. My grout lines are 1/4", so the saw is significantly narrower. I tried to cover all areas but kept finding myself with tiny parallel ruts. I finally resorted to running the saw at a slight angle. This helped, and did not seem to be damaging the tile, but I never saw any recommendations to do this so I'm wondering if it was a bad idea?

I also wasn't sure how much of the old grout to remove. I basically just got the dirty layer off.

For the whole big job I plan to use a Dremel; there are two different types of blades for this, one that's basically a powered version of the hand saw and another that uses a bit that can be set to a particular depth. Is one more appropriate than the other for this job? And can I expect to have less trouble taking the old grout off evenly?

1. The grout

I have a feeling that my grout choice was too sophisticated for me. :) I used TEC Power Grout RTU, which is a premixed sanded grout that doesn't need sealing. It sounded perfect. However, in reality it was very thick, nothing like the wet mud texture I saw in all those videos. I got it spread but it required quite a bit of elbow grease and was very difficult to get smooth.

The original grout, at least according to the builder, was TEC sanded powder grout, which I would have to order from Lowes. I had thought that using the premixed stuff would protect me against having mixed it incorrectly, but now I'm not so sure.

EDIT - I returned the grout I had bought (I have to give Lowe's credit for allowing this, since I had used some) and ordered a bag of the same brand and color of powdered grout that the builder says they used. This should help with the amount of effort it took to get it spread.

1. The application

As I said, the grout fought me every step of the way. It rolled up into balls, it stuck more firmly to the rubber float than to the floor, and was just generally aggravating. However, I did finally get it to go where it belonged. The exception was the edges, where the grout line met the wall or the cabinet. It was impossible to move diagonally over the line in those places, which is essential to working with this stuff. Is there a trick to getting the edges right?

1. The cleanup

This was the smoothest part of the process, but I did notice that by the time I got the tiles clean there were obvious places in the grout lines where it was not applied thickly enough. I don't know if this was an application failure that I didn't notice because of the covering of grout everywhere (even after scraping with the float at 90 degrees) or if I was actually wiping away some of the product. Either way, I didn't know if it was ok to apply more with the surfaces wet, so I left it alone.

This was only a test, and I fully expected to have to remove this grout and replace it, so I have already succeeded no matter how it looks. But I think I am going to have to get a different grout - the color was much whiter on the floor than in the tub or brochure, even though it's supposed to dry the same color, so we'll see. Right now it is too white for the tiles.

EDIT - having changed the grout, I have one further question. The grout I will be using is TEC AccuColor Sanded Grout. Their website describes this as a "polymer-enhanced portland cement grout" but doesn't say anything one way or the other about whether it needs to be sealed as an additional step. I think that the polymer-enhancement means it does not, but can anyone confirm that?

So - there's my tale, I'm hoping those with more experience than I can make some suggestions on how to make it go better the next time!

Answer 1

I used an oscillating multi-tool with a carbide circular blade to grind out the grout. I took it all out, and used a chisel to removed whatever remained. Re-grouting is a grueling task; I could not find anyone to do it.

Sounds like you need to thin that grout. Maybe some latex additive would help. Grout should be pasty but flowing.

When all else fails, I use tongue blades to smooth caulk and grout.

The right consistency grout will not leave bubbles and voids. It will flow and be heavy enough to sink to the bottom.

Answer 2

I cannot address question 1 although the use of an oscillating multi-tool as mentioned in another answer sounds like a good idea; I've used those tools to cut trim away near cabinets and it comes in handy for a wide variety of awkward geometry problems like that.

Question 2: It does sound like the grout could have used a bit more water. But only add water in very small amounts - it can go from too thick to too runny very quickly. If it does get too runny, just leave it alone for 10 minutes or so and it will begin to thicken. It is a tricky to force it into the space between tiles but going in several directions consecutively works for me. When you get to the edge I just used some caulk that was made for that purpose. Mine came from Lowes (which is where I bought my tile, adhesive, and grout) but seemed pretty common. It was in the tile department and was colored the same as the grout I used as well as containing some sand to match the consistency. This made the edge treatment much easier although not as trivial as I expected. Like the grout, it was a bit tricky to get the surface just like I wanted. I used my (wet) fingers a lot to smooth the surface.

Question 3: the cleanup. The cleanup of the tile surface with a wet sponge does indeed remove some grout from the spaces but wiping lightly will leave a slightly concave shape to it. I think it's key to wipe lightly but you do have to wipe many times and wash off the sponge very often. It is normal for a lot of grout to be left on the surface after the use of the float. The float is pretty much to force the grout into the gap. Cleaning was a long process requiring much clean water. I had three buckets and my wife would empty and refill them as I wiped the tile and rinsed the sponge in clean water.

This is all pretty fresh in my mind; I just did my tile job last week.

Answer 3

1. I run my dremel at an angle all of the time for wider grout lines. Actually this keeps it from jumping.

2. I am glad you ordered the correct stuff. Premix is crap and you have no idea how long it has been on shelf. When I am doing small/medium jobs I use big juice jugs to mix the grout - cut off the top few inches. Now when you are mixing just let there be at least an inch of water at the bottom and start adding grout then water and so on until it is right.

3. 90% of your problems was the grout. It should be less thick than peanut butter. Let a smooth JIF peanut butter be a barometer for the thickest it can be. Just make sure that you are making several parallel passes on each grout line, then pushes in with perpendicular, then do gentle parallel wipes for finish.

4. If you want easy cleanup I have two easy pieces of advice. 30 minutes before grouting wipe down the tiles with a super heavy Dawn/water solution. When this is mostly dry you can begin grouting. Also use Dawn when you are wiping. And every minute you should be wringing out sponge in bucket. And then every 10 minutes empty bucket for new bucket of Dawn/water. Dirty sponge or dirty water = double the time.