Tuesday, November 21, 2006

How Deep Does The Rabbit Hole Go

Yet again I find myself thinking about tile. I guess I think about it so much because it will be the single biggest expense for the bathroom, but also because it will make the biggest statement. And as we all know, image is everything. For me, it is almost always going to be form before function.

One thing I’ve noticed when looking at pictures of tile work is the old tile work has little or no grout lines. Today, when you buy 1-inch hex or square, or the penny rounds they come on the sheets of mesh and the tiles are spaced evenly. This makes it very convenient to lay the tile and you get a pre-measured quarter inch grout line – or something close to that.

When I look at pictures of turn of the century tile floors, it looks like the tiles are pushed right up against each other, and if there are grout lines, they are almost non-existent. Of course, these tile floors are laid on a mortar bed, so there is a solid, impermeable surface under the tile. Modern floors are generally laid on cement backer board and thin-set. The thin set is a Portland cement based mortar and you trowel it on with a notched trowel.

I’m working on some assumptions here, because I’m not an expert tile layer, but it seems that the notched trowel method would leave some areas where there is very little thin-set between the tile and the board. Don’t misunderstand me here, I’m not suggesting the thin-set is a less effective way to keep the tile down. In fact, I’m sure quite the opposite is true. The question is one of water infiltration. With no grout, and thin-set laid with a notched trowel, water could be a problem. I'm guessing it could be, because I don't know.

If the floor tile is laid with thin-set and backer-board, but without grout lines, is it effective at keeping water away from the substrate (e.g. backer board and/or the wood sub floor). The reason I’m thinking about all this is because I thought it might be cool to do a traditional tile floor without grout lines. If so, then would the thin-set application hold up over time, or would I need to do a traditional mortar bed as well. The one and only time I’ve seen a tile shower installation go in, the first step was a mortar bed.

This, of course, adds more work to the project. Really, it adds a lot more work because it would entail me to not only do a mortar bed, but also lay all the little hex and square tiles one at a time, by hand. I wonder how long that would take? I think I have about 70 sq ft of floor space. It’s a lot to think about. This may require a trip to the library to see if I can find and old book on laying tile, and possibly a trip to a psychiatrist.


Anonymous said...

I laid little mosaic tiles like that one time.

This was in a rental house we lived in once in Canada. There was a fifties-ish tub that would leak water over the edge every time someone showered and rotted the subfloor. Apparently this had been going on for many years and our slumlord had no intention of fixing it. It creeped me out so much that the tile was just sort of sitting there on a rotted subfloor that I dug out all the rotten stuff, patched the subfloor and laid those little tiles all back in by hand because the mesh backing that held them together had rotted away.It took me about four hours to lay about a 2 sq. ft. patch. It was a far from perfect result, but at least it was hidden between the toilet and the tub and I didn't shudder every time I looked at it anymore.

Get some really comfortable kneepads if you do it.

Anonymous said...

I do tend to agree with you about the importance about not forgetting about form, but the best form usually occurs when function is inextricably combined with the form. For tile it is hard to not have function be there also, but many people do get lazy and the form is all function and they forget about integrating form. I can’t see you doing that at all.

As for my 2 cents about historic tiling. From what I know most of the thick bed mortar jobs that you see were done because that was what was realistically available to them at the time that would get a job that wouldn’t crack. The low cost of labor and the relative newness and lack of understanding about the physical properties of concrete didn’t hurt either. Backerboard, latex additives, plywood subfloors, kiln dried joist material, ect have come a long way to rendering thick bed jobs not necessary for most typical flat floors that aren’t in a shower. As for the methods of laying the unglazed mosaics back at the turn of the century, they came on paper faced sheets that usually about 12” square and even most of the borders were pre-made. They would simply place the sheets of tile paper face up into the thin mortar bed that is over the thick bed. Once it had set they come back and wet the paper, the glue dissolves/loosens and it is removed. My understanding is that even much of the decorative mosaics from many eons back in Italy was “built” on a table or such and then installed. Unless they were setting in a lime mortar that would take months to set they would get nowhere. (end of rant)

As for the notched trowel. For the small porcelain mosaics you use a very small notch. It will probably be a “v” notch about the size of 3/16”. That is so the notch doesn’t cause the tile to wobble when you set it. No grout, man are you crazy! You are correct if you didn’t have grout, on any floor, it would leak. I believe the tiles that you were looking at in your previous post have about the smallest grout line that I have seen and it is a bit over 1/8” if I remember right.

Groutless tile???? Let us know how that works if you try. (I’m worried)

I promise I will post more photos of our bathroom along with suppliers ect. soon.

Anonymous said...

My 1950's bathroom has little to no grout between the tile. The end result for us. Rotten walls in the shower/tub area. We will be gutting the bathroom
next spring because the walls are shot. I won't miss
all the pink, yet I would rather not have to spend
the money on a new bathroom. I'd rather spend
the money in the kitchen.


Allison said...

You talked about this in an earlier post, I think, but a big part of why the grout lines look so big on modern tile is that the edges of the tile are curved - lay two curved tiles next to eachother, and the grout fills up the concavity and makes a wider grout line. It's also a more leak-proof grout line, becuse there are no blunt edges where the tile and grout can separate. If you are laying in a morter bed, you just use more morter for grout - so it all bonds. It doesn't matter in that case if the edges of the tile separate from the mortar, because the morter bed forms an inpenetrable moisture shield (unless the whole thing cracks). If you use thinset, troweled, and no grout, you are going to have leaks. Grout, especially grout on curved-edge tile is the main think keeping thinset installations from rotting the subfloor (well, that and the cement backing board). If you want to go without grout lines, you have to use a morter bed. By the 1920's, the small mosaic tiles were mounted on sheets, so most of those installations weren't done tile by tile...

Anonymous said...

For everything you ever wanted to know about laying tile check out this link:

The most important thing about a good tile job is what's underneath it. These guys are the best and will answer any and all questions that you have.


Anonymous said...

When I did my subways and hex tiles, I did the 1/8 spacers between them and it looks very authentic - the problem with doing no grout lines is twofold - water infiltration is one, and the other is no flexabilty when laying them - meaning, everything has to be perfectly square, and perfectly flat, which we know is so common in old houses.... with grout lines, you can tweak tiles a bit to account for irregularites and they will still look really good, if the tiles are butting up against each other, every imperfection will become glaringly obvious. Also remember in earhquake country having tiles touching will cuase the tile to crack or pop up whereas with grout the grout cracks instaed of the tile.