Peetster

I have a 20' by 20' room that I plan to tile. The tiles are 12" by 12". I have 480 tiles (even I know to buy extra), mastic, a trowel, plenty of old buckets, a chalk line and an electric ceramic tile miter saw. I'll get the grout and sealer after the tile is down.

Under the floor is a basement, so the surface gives slightly when people walk on it. I might screw down a layer of plywood first.

Any advice, tips, tricks or general thoughts? I've never worked with ceramic tiles.

fhqwhgads

Instead of using plywood, consider using wonderboard (concrete backer board...also goes under the name greenboard, etc.) It's a concrete board that will flex and give less, thus providing a more stable surface for the tiles. (Less chance of cracking)

You may want to buy some spacers if you're not confident that you can space the grout lines perfectly yourself. They help to keep your tiles spaced evenly and make the job look that much better when done...

Good luck to ya.

james t kirk

Lots of advice.

First, the existing subfloor, i.e. the flooring on top of the floor joists can NOT have ANY give whatsoever to it. If there is any give whatsoever, two things will happen.

1. The tiles will pop.

2. The tiles will crack.

Neither is desireable.

You need a strong subfloor to support the tiles.

1. The best subfloor is 3/4" tongue and groove PLYWOOD (not particle board since it swells, especially at the edges, when exposed to moisture) 5/8" T and G works well too provided your joists are not at their length limit for span. I.e. a typical 2 x 8 floor joist made from SPF No. 2 (Spruce Pine Fir Grade No. 2) has a maximum span. If when they built your house, they are at that span (which builders typically are), then you should consider using 3/4 T and G since it is stiffer.

You can find the maximum allowable spans in your local building code at the library. Just measure the dimensions of the existing floor joists, the centre to centre spacing and the length of the joist.

You should remove the existing subfloor (if you want the best job possible) which is a hell of a job. Clean up the joists. Then screw the new 3/4" plywood subflooring down with coarse thread drywall screws about 2.5" long. Some guys put down a layer of glue on top of the joists first, then screw down the plywood. I don't bother with the glue, instead, using the screws i have never had a bad result. Screws have to be sunk into the joists obviously and I tend to space them about about 8" centres.

Always lay tongue and grove plywood with the tongue leading, i.e. the tongue starts and keys into nothing. In this manner, you bring the second tongue into the grove of the first piece and you can use a 2x4 drift to protect the grove end of the second piece of plywood and hammer it home.

Also, you should always stagger the joints of your subfloor. I.e. like bricks. Do not have the short sides of two pieces of plywood lining up over top of one joist.

2. Once the nice new subfloor is in place, you need to lay down a concrete substrate.

Typically, i buy the metal lath from Home Depot (they have tons of the stuff) and nail it down to the subfloor using roofing nails at about 3" centres in both direction. Roofing nails are the best cause they have a broad head that can pick up the corners of the lath. Place the roofing nail right in the corner of each diamond. Roofing nails should be about 1" long. Make sure all the lath is perfectly flattened out.

You will be nailing all day. Have fun, but it gives the best job.

3. At the same time you are at home depot buying the lath, buy the concrete scratch that is probably sitting right beside the lath. Follow the instruction on the bag. You will need a big pail and a drill mounted mixing stick (ironically also right beside the metal lath)

Tip, don't paint yourself into a corner.

It's nice if you have someone to help mix while you lay the concrete scratch and trowel it out smooth.

Let the concrete scratch cure. Don't walk on it at all for at least a day, better yet 2.

I would let the concrete cure for at least 14 days, regardless of what the bag says, unless the bag says 28 days which would be even better.

4. Lay the tiles using thin set mortar (also available guess where).

You need to use the type of trowel with the teeth on one side of the trowel in order to trowel grooves into the thinset mortar.

5. Lay your tiles however you want.

Have fun.

shakran

and your subfloor needs to be 1 1/4" thick to take tile.

concrete scratch can be foregone if you use patch leveler on a good solid subfloor. I recommend a latex modified patch leveler to level out the surface of the floor. You're going for a subfloor that does not move AT ALL and is as close to perfectly level as you can possibly get it. Don't skimp on the prepwork or your tile will be wrecked.

I second the suggestion to get spacers. Use 'em. Your tile will look like crap without 'em.

When you lay the tile, let it sit for at least 24 hours, then grout it. Grout a small section of the floor at a time, and come right behind it with your wet grout sponge and get the excess off the tile - if you wait too long you'll have a nasty film on your tile that's VERY hard to get off. Be sure to use sanded grout - unsanded grout is not ideal for a floor, especially if people will be walking across it with snowy shoes. And use a grout float. Lots of people think they can get the grout in there with their finger, and they can, but it tears up your finger. I've seen some groutwork with blood mixed in it 'cause they used their finger

Seal the grout as soon as it's cured. If you don't, the grout will look like crap in short order.

Black and Decker publishes a very good floorcoverings how-to book. I would strongly recommend buying it before you start this project.

Bossnass

I've done a couple tile floors, mostly bathrooms, but 2 kitchens about the size of the room that you're planning. I asked for advice and was told much the same as that which is already posted. No 'give' in the floor is ideal.

Then I considered my time and money constraints. And, at least with my first floor, my abilities. And I said screw it, that's overkill. Professionals will use a concrete leveler subfloor (with the metal lath, etc). And they will do it perfect the first time, making it perfectly smooth and level, I've watched it be done in person, which is really what made me decide not to tackle it. I still think I'd have a hard time. Especially with a 20x20 room.

The floor I dealt with which had the most give was a t&g fir hardwood floor in a 80 year old house. It was beyond recovery as a nice hardwood floor. I used zinc deck screws to stop as much movement as possible, threw down a layer of 3/4 D grade plywood with another few pounds of deck screws, and went at it. It's been about 4 years now since that floor and there has been no problems. At least, it looks good when I visit it on holidays and the owners have not complained to me.

I've used 'wonderboard' as well, its pretty stiff and nice and thin. I still prefer to work with good old wood ply though.

I think I intially learned a fair bit from a home-improvement show called 'home-time'. They used to have a pretty good website. I also picked up a how-to book from a local tile store, which is invaluable. Can't recall the title, but it was a little old and by someone named Ramsey.

Oh, and careful chalk lines and little x spacers are a must.

Peetster

Wow, you guys really came through. I appreciate your advice, which I am definitely going to follow. I'll post follow up questions as they come up, I'm sure.

clavus

You guys fuckin rock.

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Peetster

*UPDATE*

The room is cleared, base molding gone, carpet and pad removed, carpet tack strips gone, staples gone.

I had forgotten about using X spacers, I purchased about two thousand.

The plywood subfloor isn't bad. Cheap contractors stapled the plywood onto the joists. I'm evaluating it now. I'm thinking that 5 pounds of drywall screws will give me a stable place to lay 1/2" concrete tile backing board. Two issues I'm faced with:

The air registers come through the floor. That shouldn't be a problem, except the aluminum flashing is tacked onto the top of the subfloor. Basically, I have a 1/8" tall lip extending an inch around the air vent opening. How should I handle that?

The fireplace in the room has a nice piece of slate, 6' by 3' by 3/4" thick, glued directly to the subfloor. No chance it's coming up. I don't want to destroy it. Should I tile up to it and incorporate some type of transition?

Thanks again for the help so far. You guys have kept me from making mistakes that would have destroyed the project by now.

nirol

Issue 1) Registers: Ignore the flange fastened to the subfloor. Lay the backer board over the metal. The registers should have a flange that is long enough to fit inside the new tile and backer board. You may want to fasten this directly to the finish floor with concrete screws, plastic fasteners, or my choice, construction adhesive.

Issue 2) Slate Hearth. I agree, dont mess with the slate. Get some marble thresholds from your supplier (HD or Lowes have them). Set these directly on the subfloor and but the backer board and tile up to them. This will minimize the elevation change to the slate. You will have a depression left at the hearth that will show great ability to catch dirt, but I think this would be the least worst choice.

Another issue is the one I find the biggest pain, cutting around door jambs to slide the tile under. Use a flat saw and cut enough away to hide the edge. A Japan Saw works best.

Good Luck,

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shakran

you didn't say if the slate is the same height as the tile will be. If it is, and depending on how it will look, you can tile straight up to it if you want. Only trouble is that often times this causes a major clash. If you don't like the marble idea (or have trouble finding it - the depots in my area only carry corrian strips, not marble) use a wood transition. If you stain it the right color, it can look REALLY good.

mtsgsd

You're getting a lot of good advice here, but this is something you really need a lot of info on before you do it because doing it again is not something you want to go through. I read a forum that's run by a Pro tile installer that has a lot of other pros on it from around the country and you won't believe the help you'll get there. Check it out.
John Bridge Forum

troit

mtsgsd -- Just wanted to thank you for pointing everyone to the John Bridge website. Very, very informative with an answer to just about any question one would have concerning tile work. Again -- Thanks.

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mtsgsd

No charge. They helped me out quite a bit. No question is too stupid or too repetitive.