Replies

1. 
   Guest_ | Apr 11, 2000 02:32am | #1

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   Greenmother,

   I certainly can't answer all your questions-I'll try to help you with a few. Roof slates are not well suited for floors. I've seen it pulled off once, in a small foyer.

   Cleaning-Clean them with TSP(Spic-N-Span) with a bristle brush, then rinse. If they have tar on them, it should be obvious. I wouldn't even try to use those. If they are just "sticky" then try a solvent such as paint thinner or laquer thinner.

   Subfloor-They won't add more weight than quarry tile, or any other ceramic tile, so assumming your floor has normal load carrying capacity, you'll be OK weight-wise. What are size are your floor joists and how far do they span?

   The floor I saw done with roof slate used a cement board subfloor with thin-set adhesive. He butted the slates as close as possible, and let the thin-set create a kind of grout between the slates, which he dry-brushed as the morter set up.

   After the job was installed he put a couple of coats of silicon sealer on the whole floor.

   It seemed to hold up well in this application, but doing a whole kitchen would in my opinion be risking a whole lot of effort and cost. Maybe you should try a small area first(like a mud room), see how it stands up after a year, and if your still happy with it go for the whole thing.

   By the way, because of the bevel on the slates the floor will be very bumpy.

   Hope this helps, John

1. 
   Guest_ | Apr 11, 2000 03:05am | #2

   *A woman after me own heart !!!!I like this idea. I think I would have put it down over a slab and/or a bed of packed sand myself, but we work with what we have, no ? Who cares about 'bumps' in the kitchen floor ? It's under the computer chair that we want a smooth floor. LOLJohn was correct in everything he said, as far as I can tell. Doing a smaller room first would be good for mor than just the one reason. You can make your mistakes, (and learn from them), in the smaller room and they will not be as noticeable as they would in the larger kitchen.You don't need a thicker subfloor unless you already have problems in that area. ie, the floor sags between the joists. You really should check the joists. What size 2x's are they ? How far apart are they ?I would figure the slate to be heavier than some ceramic floor tiles, probably the same as most quarried rock.

2. 
   Greenmother | Apr 11, 2000 03:37am | #3

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   Thanks for the input, fellas. I see now I omitted a very important detail from my description of the project. Two words: small kitchen. I'm looking at maybe 70 sq. ft. of covered floor, tops. Still too big, do you think? I can always use the slate for something else, if I must. (My husband drove 12 hours, some of it in a snowstorm, to pick it up, so I HAVE to use it for something!) I don't mind a bumpy floor, but if there might be a structural problem, I definitely want to know. Also, the little guy who runs the tile dept. at our local building superstore (my MIL works there and we can get her discount) says I should set the slate, then seal it...twice...before I grout it and then seal it again. Won't those initial applications of sealant interfere with the grout's adhesion? I'm intrigued by John's friend's method of putting down the slate w/o grout. Did the beveled tile edge make this method work, or did he put down a thicker than usual thin-set layer? I have free use of a really good tile saw for the duration of the project. What if I sawed the worn edges off the slate and maybe cut them into smaller pieces? Would that make a difference? (I got a good enough deal on them to feel OK about putting extra work into the project.)

3. 
   Guest_ | Apr 11, 2000 04:22am | #4

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   Greenmother,

   There probably is no structural problem with a floor that small. But please let us know the joist size, spacing, and span. With a small floor area you probably don't have a micrwave cart or chairs that would be a problem on a bumpy floor. So with that new info I would say go for it!

   The "worn" edges are actually beveled by the cutting action of the roofer's slate cutter. Since this is a non-standard floor anyway, why not keep the edges as they are, and do it the way my friend did? Don't try to make them look like floor slates. Let them look like the roofing slates that they are. You will save the grouting step and have a more unique looking floor. The thin-set was laid at the normal thickness, and the slates were laid as close as possible. What you could see of the thin-set hardly looked like grout.

   See if you can find a roofer's slate cutter to rent or borrow. (My friend was lucky, I provided the slate, the cutter, and the cuts, while he laid the floor.)They are very easy to use, they cut by pushing down on a handle(something like a paper cutter). You place the slate bottom side up, and nibble your way through. No electricity, no water, no diamond blades, very low tech, but the perfect tool for the job. You can use your imagination and cut some diamond or triagonal shapes for an interesting effect. (I've done this on some coffee and end tables).

   John

4. 
   Mark_T. | Apr 11, 2000 08:17pm | #5

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   Luka:

   You say "I think I would have put it down over a slab and/or a bed of packed sand myself"

   1/4" slate over a bed of sand? For an interior application?

   One minute your talking concrete, the next, "You don't need a thicker subfloor unless you already have problems in that area. ie, the floor sags between the joists." Seems like you can't make up your mind.

   Any ceramic or stone veneer floor covering applied over a traditional framed floor needs some kind of mud bed or cement board underlayment.

   What kind of a builder are you anyway? Let me guess: Specializing in small utility structures with 1/4 moon monograms on the door, 1 & 2 seat models available?

   You ought to just stick to your regular off the cuff, windbag remarks, rather than actually trying to give building advice!

5. 
   Greenmother | Apr 11, 2000 08:45pm | #6

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   Hello, everyone. I've salvaged some slate roofing tile for the floor in my new kitchen. Structurally, it's in great condition, but it needs to be cleaned. I have no idea what it's been in contact with as far as the roof it was attached to is concerned. Should I simply hose it down? Or do I need to use some kind of exorbitantly expensive caustic substance? In addition to the black powdery residue on all the pieces, some of them seem to be a bit sticky. I have no idea why. Smells a little like tar. Any suggestions? Also, these things are 12" X 24" X 1/4" and weigh about 5 lbs. a piece. I've been told I'll need a thicker subfloor in the kitchen to accomodate the extra weight. How do I calculate such a thing?

6. 
   Guest_ | Apr 11, 2000 08:45pm | #7

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   HAHAHAHA

   Now c'mon, Mark, can't you take yourself just a bit more seriously ???