grouting advice / guidance needed [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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02-24-2008, 10:28 PM
There are many types of tile backerboards for walls. I'm leanign toward 1/2" HardiBacker. Howerver, in my area, there is also Durock, DensShield, Wonderboard. Which is prefered & why.

Also, aside from 4 X 4 thin ceramic tiles for the walls, what would be some other alternatives in both size & material that would look good for a small 5 foot by 3 foot, 3 wall alcove tub & shower. We have looked at some 8 X 12 travertine tile, but I see other posts saying travertine is not good for shower walls. Other suggestions please. Oh yes, I would like to incorporate some type of decrotive band within the tile pattern.

Thanks, FJK

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02-24-2008, 10:34 PM
Hi FJK, welcome. The CBU used is just person preference. Some will recommend Backerboard, others Durock, someone else will like Wonderboard. You'll get different opinions on that but all of them will work. Just put a moisture barrier behind it first, whichever you use.

We install alot of stone in showers although there is more work keeping it maintained. I would use a porcelain tile that looks like stone.

Check out some local showrooms, you'll get plenty of ideas. :)

03-06-2008, 12:28 PM
I picked up one of those flanged plastic boxes at a tile shop, to create a recessed shelf in the tub/shower. This gets installed between the studs. The tile shop guy says you just apply your thinset & tiles right on the plastic surface. I would like a confirmation if this is OK. Thanks, FJK

Scottish Tile and Stone
03-06-2008, 01:01 PM
How are you going to waterproof the rest of the shower?

03-06-2008, 03:46 PM
Plastic 6mil or roofing paper, then 1/2" cement board

jim mclaughlin
03-06-2008, 04:36 PM
That is your vapor barrior. Waterproofing would be a surface applied liquid such as red guard or laticrete hydroban or a surface applied membrane like kerdi. When I say surface I mean on top of your cement board

Could you be more descriptive when you say plastic box, the pre made niches I am familiar with are cement covered foam pieces that are waterproof. Do you have a manufacturer for it?

03-06-2008, 06:47 PM
No manufacturer, just a plastic box with flanges; got it from the Tile Shop.
Also, what is red guard? Why is that needed? Old tile wall was ceramic with adhesive over drywall. Lasted 30 yrears.

03-17-2008, 10:56 PM
I'm installing new 1/2" hardi cement board & new 1/2" drywall. On the common stud where the seam occurrs (cement board meeting drywall), does the seam get taped & finished with drywall mud or thinset? The final tile will be a 3" x 12" bull nose (not a "mud cap"), so about 1" of the tile will overlay the seam on to the drywall. Also, I notice the drwall surface is slightly above the cement board surface by up to 1/16". If this is an issue, how is it corrected? I'd rather not wait until I'm tiling to see if this is a problem. BTW, the 3X12 bullnose trim & the 6X6 primary tile is pretty thick, about 7/16" thick.
THanks, FJK

Tool Guy - Kg
03-17-2008, 11:18 PM
Tape the seam with alkaline-resistant mesh tape and mud it with thinset. Be careful to not allow the thinset to get outside the tile's "footprint" where you plan on painting. Blue painter's tape helps out a lot here. :)

About the thinner Hardibacker...not to worry about the tile being "ramped" at that edge. :shake: The setting material will more than make up for that difference and the tile can be installed in a nice, flat plane. :)

03-25-2008, 05:39 PM
Back to the shim deal. After driving myelf crazy over the mismatch, I cut shims out of 1/8" hardboard. After I'm done, I discover at the local Menards drywall shims in the sheetrock asile. A giant package for 6 bucks. Made out of cardboard(?), the width of a stud, maybe 2' long. Maybe this will help someone down the road.

04-28-2008, 09:51 PM
I'm wall tiling a 3 wall tub/shower. I'm using 6" square tiles, actual size 5-3/4 X 5-3/4 with 1/8" grout spacing. The wall is 59 3/8" wide. Ideally 10 tiles across will work perfectly. Now, the issue. I have a 13-3/4" square recess shelf box installed in the wall, but the center line of the box is offset 1-1/2" from the center of the wall. My significant other says I should use the center of the box as the centerline for the tile, which would result in cut tiles on the end columns of tiles, 1 column 1.8" wide, the other column the tiles would be 4.7" wide. I think this would look bad. As it is, as the rows come up toward the bottom of the box, I have 1" open from the bottom of the box from the last full tile. Here I'm planning on using a strip of 1" square tiles.

What are the layout alternatives for this box? Do I tile the box perimter first & layout from there? Or, tile the wall first & do whatever to fit the box tile to the field tile of the wall. I have no artistic vision to "see" what would look best. How do should this be handled? Also, as a side note, is there any computor program for laying out tile & grout spacing to scale? I'm getting a headache from trying to figure this out. Help!

Thanks, FJK

04-29-2008, 04:26 AM
There are 2 schools of thought for this problem: 1) the tile setter's artistic interpretation governs the process and layout, and 2) doing what the boss says. :D

Really, it's a matter of compromises to achieve a pleasing and workmanlike end product. I think that your layout makes sense, but the niche interrupts the pattern in the middle of the field. Framing the niche with bullnose tiles (or some other shape) may make this less noticable. I'm not sure of your plan to use 1" squares under the niche, unless you frame the whole thing with them. Just under the bottom will look like you tried to avoid cuts.

04-29-2008, 04:26 AM
I would ignore the box as far as the layout is concerned. Your outside vertical rows of tile will be more noticeable than the cuts inside the niche.
There's different ways to do the niche.
You can have your groutlines continue through like it sounds like you were planning.
You can put the bullnose trim on the outside of the niche with the rest of your wall tile (this would eliminate the 1" problem but cause more cuts) then split the back into 4 equal size pieces creating a window look.
Same as above but put the four pieces on a diagonal
Same as above but put the horizontal line higher for a religous effect (cross).
Put a different tile in the back like a fancy glass tile or some funky looking listello.
Don't get tied into anything because " that's the way it's done". It's your tub/shower. Think a little bit and you'll be able to get something you like. Normally when it comes to tile, some designer dreams up something that they think would look really nice. It's our job to figure out how to make it work. So think of something you like then we'll try to make it woirk.

05-10-2008, 07:49 AM
I'm doing wall tile on a tub surround with 6X6 tiles, thinset, cement board.
2 questions
The tile is about 1/2" thick & is rated as floor tile. Is it too thick (meaning too heavy) for wall tile? Any special considerations doing this?

2nd question: We want to intermingle about 10 decrotive 6X6 tiles in the field, but these tiles are thinner, maybr about 3/8" thick. The plan is to back butter with extra thin set to get them flush with the ticker tiles. Is this OK & will it work?

The little lady wants to do this; I'm nervous about it. Please advise.

Thanks, FJK

Brian in San Diego
05-10-2008, 08:10 AM

The first thing I would like to be sure of is that you properly waterproof the surround for the tub. If it's a tub only with no shower then you should be O.K. with just your cement board application. If it's a shower then you need to do more waterproofing...either by properly installing poly behind the cement board or applying a surface membrane like kerdi or a paintable one like Laticrete Hydroban or Custom RedGard.

Now for the tiling question. The weight of the tiles will make no nevermind (within reason). You can add thinner decorative pieces by the method you describe. Some have made jigs to put down a layer of thinset to the proper thickness and then applied the thinner tile to that thinset.


05-10-2008, 10:28 AM
Hi FJK, what Brian said. :)

05-10-2008, 02:00 PM
Thanks guys, I guess this is doable. Amyother advice?

John Bridge
05-10-2008, 02:05 PM
Welcome aboard, FJ. Wanna give us a first name? ;)

08-15-2008, 11:06 AM
The last time I grouted new tile was a few years ago & I lost track of some of the finer points.

I will be grouting newly installed 6X6 wall tile on a 3 wall shower/tub alcove. Grout spacing is 1/16", total square footage is approx 48 sq ft & I will be using unsanded, colorized Mapei grout that you mix from powder. I have a 10 lb bag.

The laast time I mixed grout (for a floor), I THINK I hand mixed it & I think it was drier than it should be.

Now the questions for the wall job described above.

Is it OK to mix using the drill motor / paddle mixer I used for the thinset?

What consistancy should the grout be, relative to how I mix thinset? (I do a good job mixing thinset).

What is the bucket life of the mixed grout? (My thinset is 2 to 2-/2 hrs)

I'm thinking of only mixing 1/2 of the 10 lb bag because I'll probably be working slow due to my inexperience. What is the thought here?

Should I expect the grout on the walls to start running down, or will it be controlable on the wall? I assume start top down.

Any other pearls of wisdom to share with me?

Thanks, FJK (Jim)

Dave Taylor
08-15-2008, 11:32 AM
If you mix grout and it runs..... you prolly' are mixin' it too thin...... cut back a bit on the liquid.

The May/June 2008 issue of TileDealer Magazine has a rather comprehensive answer to you comprehensive question.

The article is part of the Installer Update series and may be found HERE (

It is an easy read and contains just about everything on 'cement' grouting one wants to know but is afraid to ask.

Hope this helps.

08-15-2008, 09:45 PM
Good info. Thanks for the link Dave. Anyone have an idea on bucket kife for the grout I' going to use?

Tool Guy - Kg
08-15-2008, 10:34 PM

Pot life varies among those made by Mapei. Check your bag...or tell us specifically which grout you're using.

You'll likely only need about 5 pounds total. Mix up 1/3rd of that grout and get used to the cycle of cleaning up after it initially sets up (grout in joint doesn't dent inward with a light touch with your finger pad).

And I work from the bottom upwards. I deliberately keep the float handle down while the edge is tipped into the wall to create a "ledge" for the grout. I can keep the pile of grout mostly maintained on top of the float as I swipe the float from side to side. If you haphazardly turn the float every which way, you'll go through a lot more grout due to so much dropping on the floor as you work. :)

08-15-2008, 10:45 PM
Welcome, Jim. :)

Some housekeeping first. I've combined half a dozen threads for this shower here. Please bookmark this thread and use it for all you project questions so we have a history and what's been previously axed and answered. We can give it a more generic title if you like.

Also, please go to the UserCP above, find Edit Signature and enter your first name there so it appears in each post for folks to use. :)

08-16-2008, 09:52 AM
Tool Guy: You always seem to reply to my questions with good advice. Thanks. I'm looking for pot life for Mapei Keracolor U non- sanded grout.
Thanks, Jim

Tool Guy - Kg
08-16-2008, 08:49 PM
For your specific grout, pot life is 2 hours at 73°F according to their website. Pot life is shortened in hotter temps and lengthened in cooler temps.

CX has excellent advice about keeping all your info and questions together. You can see from this last question that we need specifics to give you accurate info. And finally, you can use the link in my sig to add your name in your sig. :)

08-17-2008, 03:57 PM
I'm not sure if I'm mixing the grout correctly, even though I weighed out the amount on a scale & divided the water recommendation accordingly. I was trying to mix 1/3 of bag, a little over 3 lbs. I then added 18 oz of water & started power mixing in a 5 gallon pail. First off, mixing for 10 minutes seems excessively long, especially if I'm using 1/3 of a 10lb bag. The consistancey was like soft peanut butter. I thought this was too thick, but used it anyhow. I spent more time sponging the tile than grouting (I thought). It also set up pretty quickly. As a result pot life was only 1-1/2 hours. The next 3 lb batch I added 4 oz more of water. This allowed the grout to flow better, but as I went along the grout in the bucket was setting up. I'm thinking mixing a small amout of grout in a 5 gallon bucket allows too much air to affect the grout. It was apparent I would not have enough grout to finish, & when I mixed the last 3 lbs, I totally blew it, making it too runny to use. So, back to the tile store tomorrow to pick up more grout. I should also point out the tile has beveled edges, so the "as floated" grout line is much wider than 1/16", so I have to get in there to sponge out the excess.

Any direction as to the consistancy of the grout I'm mixing.

Thanks, FJJK (JIM)

Tool Guy - Kg
08-17-2008, 06:49 PM
It's describe a lot of different ways. I tell folks to shoot for "creamy peanut butter" consistency. Stick with what you called "soft peanut butter".

Remember that undisturbed grout will stiffen up when left in the bucket...that's normal. Every 10 minutes or so, use your float or a margin trowel to mix up the remaining grout. This will loosen it back up and make it easier to work. It will also allow you to keep your grout for the full pot life time. Also remember that if it's warmer than 73°F, the pot life is going to be shortened. :)

08-18-2008, 07:37 PM
Picked up another bag of non-sanded grout & finished my walls. I think I finally got the consistancy down pat. Thanks, Tool Guy. I figured I should just finish the job & grout the floor.. 12X12 tiles, 1/4" grout lines, 30 sq ft, sanded grout. Got'er done, but I think my procedure could use improving. Here's the deal. I only had one ten pound bag of sanded grout, & according to the coverage table on the bag, it looked iffy if I could make it with 1 bag. So I mixed the whole 10 lb bag, consistancy was good. I grouted the entire 30 sq ft & the grout was starting to stiffen up before I was done. Remixxing did no good. Then, it was somewhat of pain to start sponging off the grout. Had I sponged half the job first, the grout would have really set up in the bucket. So, what's the trick? Am I just slow, did I mix too much grout, was 30 sq ft too much in one shot? I would like to get better at this.
Thanks, FJk

08-18-2008, 08:14 PM
Jim i think you should watch a pro do it at least once. I can grout 500ft. by myself in half a day with no problems.If you get the consistency right, and the angle of the float along with a semicircle wide angle movement when floating you will succeed.Depending on the tile i will sprinkle a little wate on the floor to aid spreading.But by far,letting grout sit too long, grout mixed too thick, and not allowed to slake is the biggest reasons for grouting being difficult. :bow:

08-18-2008, 08:47 PM
All I can say is that I followed mixing directions on the bag. How much grout do you mix up in 1 setting for 500 ft?

09-04-2008, 10:23 AM
I'm using Mapei grout & caulk. I've been using non-sanded CAULK for the bath tub walls. Now, all I have left to do is caulk the floor to tub joint. I think I would continue to use the non-sanded caulk, but should I use the sanded caulk on the floor to match the sanded grout on the floor. This is the first time I ever heard of sanded caulk & I am thinking it is probably used to repair sanded grout, rather than be used for initial installation. What do you guys think & why?
Thanks, FJK

09-04-2008, 11:14 AM
Re. Sanded caulk: I am thinking it is probably used to repair sanded grout, rather than be used for initial installation. Not really, Jim. Sanded caulk is for matching up to sanded grout AND is for relatively larger spaces (greater than 1/8") where using non-sanded caulk can result in excessive shrinking and cracking. My experience with Mapei non-sanded caulk is it is rather thin, without much body and will shrink up quite a bit. That may not be an issue around your tub, but I can't see it very well from here, either. ;)