Installing Slate Floor Tile

[rcecale]

Prep work has begun on my next home improvement project. I've got a little over 800 sqft. of kitchen/pantry/breakfast room/bathroom/laundry room to cover.

I've started pulling up the linoleum and refastening the 3/4" plywood with screws. Each existing nail is getting a 3" screw installed an inch or two away. At 800 sqft., I've got my work cut out for me.

After doing quite a bit of shopping, both at local retailers, and on-line, my wife and I have decided on the tile. Locally, it's called Jack Rustic, online it goes by the name of Rusty. You can see why in the pic below.



I'm a bit concerned about the weight of this stuff though. For the area to be covered, I'm looking at a little over 3 tons of slate (est. 6228 lbs shipping weight). This averages out to just under 8 lbs per sqft of floor.

My floor joists are 16" on center, and as I mentioned above, the subfloor is 3/4" plyboard. I also plan to cover the entire floor with 1/2" backerboard. There are also a few areas that aren't quite level, so a bit of leveling compound will be called for in those areas. All in all, I'm looking at prolly 10 lbs/sqft. (And that's not counting the weight of the thinset and grout.)

The entire area covered by all of this slate sets over my basement, so I'm wondering if I might need to add a support post or two to shore up the floor.

Aside from the question of support posts, is there anything else that I'm missing here? I'm all about asking lots of questions before hand, as I'm also all about doing it right the first time.

Randy

PS. Oh yeah. My friendly neighborhood contractor quoted me $6.00/sqft for labor. This included everything. tearing out the old flooring, leveling, etc. It does NOT include any of the materials. Does this seem reasonable?

[azasadny]

Randy,
That's going to be beautiful! I wish I could help you, but I've never done slate or tile, only hardwood. $6 a sq ft for all labor seems reasonable since I was quoted $4.50 a sq ft to install Oak hardwood. I installed the Oak myself and had it professionally finished. Installing flooring is back-breaking work and is hard on the knees, even for a Marine!

[rcecale]

Thanks Art! I have to agree, this stuff is going to look fantastic once it's in place. We've looked at a lot of tile, and this stuff just seems the best match for the other existing fixtures...black appliances with stainless steel trim, maple cabinets, cupboards, chair-rails and baseboards and a granite countertop with flecks of the same kinda brown found in the tile and maple.

My wife even went so far as applying Venetian Plaster to the wall between the chair-rail and the floor. The plaster has a hard-granite look to it.



I have a dozen or so 16"x16" slate tiles, and a dozen 6"x6" tiles for the border that I've arranged in front of the plaster, just to get an idea, and it motivates the heck outta me to get started.

We've considered having our guy do the work, but there's just something about doing the job myself that is really enticing. When it's all done, to be able to say, "I did this!" is a great feeling!

As far as you helping, well, let's just say that, this job isn't gonna get done over a weekend. So, as long as I'm working on it, you're more than welcome to swing by...if you happen to be in the area, of course!

Semper fi!

Randy

[JavaBrewer]

The Pelican equivalent for Tile is John Bridge. I believe they have a calculator for determining if your existing flooring/joists are up to the job.

Also if it were up to me I'd cut the grout line width in half (or more) from the picture you posted. Those are too wide and with the grout color contrast breaks up the slate and looks busy. At a minimum go with a darker gray or complimentry grout color.

Oh and $6.00 sq/ft sounds pretty good as long as they have experience laying this stuff. I would also suggest you spend the extra $ for gauged slate for flooring applications to avoid tripping points.

Good luck!

[Dottore]

We have the IDENTICAL tile on our patio at home. (I would post a picture but we are not at home this week.)

A couple of comments: we love this tile outside, but it is naturally uneven, and even has a few sharp edges where the slate was split. I'm not sure how good this would work indoors - particularly if you have kids running around in bare feet etc. It will certainly ruin your wife's nylons - should she walk around the house in these.

In the picture you posted, you can see these sharp edges: they are the bits ringed in white.

Also: the rust coloured stuff is iron ore - or something ferrous. Unless you seal the tile properly, this rust colour will rub off a bit on your feet and socks, and may also crumble slightly in some places. As I said, we love the look of these colours outdoors, but I cannot imagine that this tile is very practical to have in the house.

[Moneyguy1]

There was an episode of "Holmes on Homes" that addressed a kitchen that had bouncy floors. Mike doubled the floor joists and recommended a post which tha owners did not opt for due to plans to finish the basement. I would pay a structural engineer the couple of hundred to get a professional assessment before I did the floor. Back east, I tiled a kitchen but at the same time put in a basement half bath immediately beneath it. This required walls which stiffened up the kitchen floor considerable (no bounce).

[rcecale]

Originally posted by dmoolenaar
The Pelican equivalent for Tile is John Bridge.

WOW! Great site, David, thanks! I found the John Bridge Home Page just yesterday, but didn't notice the forums. If the folks there are even half as knowledgeable and helpful as Pelican is, I'm in good hands!

I agree with your comments about the grout line. For the tile I'm intending to use (16"x16"), the most common recommendation I've seen is 1/2", but that just seems to wide. I certainly will not go any wider than 3/8" but am actually leaning for 1/4". And also, dark gray is the color choice. It will look better with the tile and also go really nice with the Venetian Plaster on the walls.

Great idea about the gaged slate! If anyone will find a tripping spot, my wife will (but don't tell her I said this! )

Dottore, part of the plan is to seal the tiles before grouting. There is a compound available that seals them very well and keeps the grout from getting into the nooks and crannies for a much cleaner finish. I'd love to see pictures of your finished work...and any you have of in-process too...you can really learn a lot by looking at those.

Bob, I'll do a search for that show, Holmes on Homes. Perhaps they have some on-line data to share.

As always, thanks for the insightful replies!!!

Randy

[speeder]

Good-looking tile, and the venetian plaster looks great as well. Do you know what the product was that she used?

[fastpat]

Years ago I wanted to put that kind of tile in a kitchen. My contractor strongly recommended I do some other type of floor covering unless I was going to pour a slab to install it on. His reasoning was that, no matter what I did, the floor joists will move around when walked on, or moving appliances in and out of the room, or other things and that would mean cracked tiles and forever regrouting the floor. This was in a house built in 1917 with real 2x12 hard pine joists with bridging. Cutting the stuff was like cutting oak.

There is one thing you might do to reduce the movement, and that's replace the subflooring with cement (aka green board) and a thinner sheet of plywood, but I'm not sure that would work to stiffen it up. You could lay cement board on top of your current subflooring which would make it much stiffer, but a lot more weight which might be getting towards the limit of your structure.

We had a tile floor in CA laid down directly on particle board by the PO, and it did exactly what the contractor warned me about all those years ago.

Then, last, ceramic or quarry tiles are very unyielding, anything made of china or glass will break if dropped on it, and it's hard to be standing on for long while cooking.

It does look great, though.

[rcecale]

Originally posted by speeder
Good-looking tile, and the venetian plaster looks great as well. Do you know what the product was that she used?

Denis, what she used was a product offered by Behr, called Venetian Plaster. They offer a range of colors, but their gray wasn't quite as dark as what we wanted so we just had the guys at HD mix our own color from a paint swatch.

Here's a pic I staged, to show what I was working with. The 6" tiles will work around the border as shown in the pic, but the 16" tiles will be turned 90 degrees. The black in the pic is the door to our refrigerator. I am really motivated about getting this project underway.



Pat, the weight of everything, as stated above, is my biggest concern here. With 1/2" backer board, grout, thinset and of course, the tiles themselves, I'm guessing about a 10 psf weight increase. Perhaps a structural engineer is called for. I think I'll cruise the John Bridge forum David provided above and see what they have to say about it. I certainly don't want to cause a cave-in!

Randy

[LakeCleElum]

I'm building a retirment home and have that identical tile in my bathroom. I bought what is called "honed slate" and it it all flat and does not have the uneven edges the regualr "slate" has. Don't worry about the load on the floor, it's designed to take it. (In my cabin, I built a brick wall behind my wood stove that is 10 ft tall, no extra support and no problem after 20 yrs).

My bath is approx. 16 X 16 st, but not tile where the tub, shower and cabinet are. My tile guy charged $1,800 to install, but that include doing the sides of the tub, wall around the toliet and the counter tops.....I think the bid of $4.50 is more than fair....You'll luv it.....

[Moneyguy1]

The point on particle board is well taken. I can think of no building product that is more prone to moisture damage and swelling than that. Never apply any kind of tile over particle board. In fact, never use particle board for anything you wish to last...

[porsche930dude]

weather or not your floor sags depends how big your floor joists are and how far they span. If its a relatively new house you shouldnt have a problem. Codes are usually way overkill on these types of things. For your subfloor you can most likely get away with 3/8" cement board to save a little weight. Or if your plywood is sold as can be iv torn up slate floors that have been put down directly to the plywood which was extremely well attatched. They sell bonding agent for this type of application. Im on a job right now that we did just that. We tore up the slate tile that was applyed directly to the subfloor. Then the homeowner wanted heated tile floors so we just left all the crap ont he plywood and they ran their heat tape. then we floated the whole thing in with self leveling thin set and bonding agent and went over it with the new tile. It came out great. I guess time will tell if it holds up or not. But thats what was recommended

[porsche930dude]

Originally posted by Moneyguy1
The point on particle board is well taken. I can think of no building product that is more prone to moisture damage and swelling than that. Never apply any kind of tile over particle board. In fact, never use particle board for anything you wish to last...

Trailers are built with particle board floors 24"on center haha. Then they make the walls out of 2x4s ripped in half and placed sideways to save space. there 24" oc too. Its laughable but suprizingly there not all that bouncy

[porsche930dude]

Originally posted by LakeCleElum
Don't worry about the load on the floor, it's designed to take it. (In my cabin, I built a brick wall behind my wood stove that is 10 ft tall, no extra support and no problem after 20 yrs).

Thats against a wall where it is supported directly by a foundation. If you built that in the middle of the room it would be a differnt story i guarantee you.

[SLO-BOB]

I did a similar tile in my entryway this fall. It is along an outside wall, but it receives a lot of traffic and the floor joists run along it's length, not across. I cross braced underneath and I used 1/8th Hardibacker. I also used very tight grout joints. In the pic it looks like grey, but the grout was darn near black.

So far, so good. No cracking or creaking. I did it myself in two days. The key for me was to lay the whole tiles, rent a wet saw, and then cut lay the rest. I also did a large kitchen in my old home with slate pretty much the same way. Never a problem.

[Moneyguy1]

800 square foot kitchen, probably 650 actual square feet of slate at 6.5 lbs/square foot. Looks like a minimum of 2 + tons, mostly in the center (no tile under the cabinets, right?) Trying to imagine a close to full size sedan parked in the middle of a kitchen.......

Pariticle board and water....totally different when the PB is protected and when it is used as an underlaiment for tile. Water can infiltrate the grout and swell the Particle Board. Consider a waterproof membrane such as 15 pound felt under concrete backerboard.

[rcecale]

Slo-Bob, your tile looks great! That is the look we are going for. Just gotta love those colors!!!

Bob (Moneyguy), It actually IS right at 800 sqft for tiling. It's also a lot more than just the kitchen. Here's a drawing I did of the floor plan. In addition to the kitchen, it also covers the pantry, breakfast room, hallway, bathroom and laundry room.

(The grid is a 4"x4" square)



Randy

[trekkor]

The floor will suport that load.

Use 1/4" HardieBacker, embedded in acrylic modified thinset, fastened with 1 & 1/4" roofing nails. Rent a nail gun and compresser.

Screwing down the subfloor is a good plan. Just use 1 & 5/8" coarse sreetrock screws and a sheetrock screwgun. It'll just take a bout 4-5 hours...if that.

The biggest advice I can give, is to use a 1/2"x1/2" notched trowel.
use straight acrylic in your thinset and pre seal the tiles twice before grouting. Then seal them twice more three days later.

This is a HUGE do-it-yourself project, BTW.

If the price you were quoted is by a legit contractor that really has experience and references... Hire him!
That price is ridiculously CHEAP!!!

Look at the slate section on my website in my signiture.


KT

[fastpat]

Originally posted by rcecale
Slo-Bob, your tile looks great! That is the look we are going for. Just gotta love those colors!!!

Bob (Moneyguy), It actually IS right at 800 sqft for tiling. It's also a lot more than just the kitchen. Here's a drawing I did of the floor plan. In addition to the kitchen, it also covers the pantry, breakfast room hallway, bathroom and laundry room.

(The grid is a 4"x4" square)



Randy

Randy, I can't be sure, but from the look of it, your kitchen needs to be much larger. Roughly, it needs to be about 1/2 the space of the kitchen and breakfast room combined. The kitchen can't be too large. The pantry is of good size, and that's great. I don't know how much trouble it would be, but just looking at the drawing, I'd say the breakfast room needs to be the kitchen, and the kitchen needs to be the breakfast room. That's just the opinion of one who cooks sometimes, I could ask my wife, if you wish. She cooks way more than I do, and she's a gourmet cook.