installing Granite tile countertops

i am going to install granite tile countertops in my kitchen. i was hoping someone could point me in the direction of a tutorial or some detailed directions. I have put down ceramic before, but i know this is different.

thanks!!! any suggestions will be appreciated.

 

The stability of the underlayment supporting the granite tile is crucial. Here is something I have written in the past as a basic how-to. If Tilebri is around he can offer further advice.

Stone tiles need an even more stable substrate on which to set than does ceramic tile, so I always advise to do as follows:
Install two layers of 3/4" BC grade plywood, screw the first layer into the bracing and supports of the cabinets. (Any open span of 4' or more in the cabinets should get a cross brace in the middle of the span if possible, obviously not doable around a sink.) Screw the second layer into the first layer of plywood.

Cut the opening for your sink, should be the drop in kind, not an undermount. Paint on some liquid waterproof membrane around the edge of the cut opening and on the edges of the plywood in the opening and along the edge and bottom of the face of the counter.

Install a bed of thinset with a 1/4" notched trowel over the plywood and lay down a 1/4" sheet of cement board. Use cement board screws or galvanized 1 & 1/4" roofing nails (hot dipped if you can find them) to anchor the cement board into the plywood. Tape the seams with backerboard mesh tape and flash with a coat of white modified thinset using a 4" spackle blade.

If tiling the face of the counter, cut the cement board into strips at the width you need to fully cover the face, predrill, put up a layer of thinset and use screws to anchor the cement board strips. Nailing straight in is not advisable on a small strip as it may split the board. You could also avoid this part entirely by putting up wood nosing trim that matches your cabinets. If still want tile there, check some local granite fabrication shops ( places that make 1 piece granite tops) about them putting a bullnosed edge on the granite tile. I have also heard of people using a metal decorative tile listello as edging and they say it looks great.

Use white modified thinset to set the granite tiles. I usually try to set a full tile along the front but the size of the tile and the size of the surface to be tiled will dictate what looks best. If "L" shaped try to run full tile from the crook of the L in both directions. Keep a 1/8" gap at the back where the counter meets the wall to allow for seasonal movement of the wall. Fill it with caulk if the opening will remain exposed, don't put anything in it if you are running tile up the wall as a backsplash, but do leave another 1/8" gap between the bottom of the wall tile and the granite surface and fill this gap with caulk, not grout. Use at least 1/16" grout line for the granite, dont go over 1/8" as a grout line. After grout has set up 48 hours you can install the sink and start using the top.

 

I just finished doing 48 Sq ft, of granite counter top. Although I did see this recomendation for 2- 3/4" ply underlayment, I did some checking and the local lunber yard sells 1" plywood with multiple plys for laying under granite counter tops. This is what I used. It is like concrete and it will not flex. I did add some support around the dishwasher and in the corner where there was little framing of the cabinets. The other thing that happens is that the counter top will be much thicker than the old formica top. If you do the math, it is vastly different. 3/4 plus 3/4 plus 1/4 backer board plus 1/2 granite. I reduced thsi by using the 1" ply, 1/4" DenzShield and 1/2 granite.
Youalso need to add the thinset thickness to the whole works.
The clamps for your sink will be custom as they don't make extensions.
I drilled out the holes inthe clamps and used 3/16' bolts 2-1/2 inches long with wing nuts to secure it back in place. the 3/16 screw heads should fit in the moutning channels.
Do not use plumbers dope to seal the sink ont he granitebecause it is oil based and will leach and discolor the tile. I used silicone calk on the sink before I set it into place. It's messy but works fine.

I also used #6 shotgun lead shot to set all the granite at the same height, I put one shot in each corner and pressed them into place. Assuming that the underlayment and backer boards are REAL flat, it works great. keeping the granite flat and even was my biggest concern. I used a 3/8 deep x 1/4 trowel for the thinset under the granite.

 

I haven't gotten the 2005 version of TCA's Tile installation handbook yet but I'm willing to bet there is no revision in there that calls for using shotgun pellets as a leveling device for setting granite tile. That sounds like a home brew remedy and while it may work for Dogman it is not something that should be casually recommended to someone who may be a novice at setting tile. If the tile is too low, put more thinset under it, not a lead ball.
As far as using the the 2 layers of 3/4" the TCA book also calls for a minimum of 1 & 1/4" of suitable plywood rated as underlayment, not sheathing, to be used on floors having 16" O.C, floor joists. I understand that this is not a floor and I understand that people most likely wont be walking on your counters, unless you throw some wild parties, but there are open spans in cabinets that can go up to 36" across and 20 to 24" deep, which is a much larger span than 16". That is why I stated to use the 2 layers. The cement board does not add any stuctural strength to the counter, it is there to give you an optimum bond of tile to substrate. Stone on a floor is more tempermental than ceramic and requires twice the rigidity measured in a floor than does ceramic. Appliances, bags of groceries and pots of water can all put a lot of pressure on the substrate to support the granite. I dont understand Dogmanh's need to have a thin substate, thin doesnt give you the strength you need under the granite. You are going to spend a good buck on that granite, set properly it will outlast everything alse in your house, set improperly you will be replacing it with Corian in under a year.

 

You are correct, it is not a floor. My cabinets are 24 deep by 18 wide for most sections. When they were wider, I added support.
Yes, backer board of any type is NOT considered strengthening. So 1/4 or 1/2 for a counter top makes no difference.
Basically, why apply flooring techniques to a counter top or shower walls?

Those pellets only let the tile to press so far into the thinset, hence they are ALL at the same height the first time. On 48 sq. ft. I never lifted a single tile once it was placed.
While you as an expert seem to think lifting a 12x12x1/2 piece of granite out of thinset after it has been pressed, is easily said, it is quite another thing to do and quite messy for a novice.
Maybe the guys who wrote the specs, never thought of it.
I looked for plastic pellets but nobody makes them that size.

Anyway, good luck my friends.

 

On thing about the pellet method is that you cannot ensure 100% contact of the granite to the thinset--required for stone installs. Most stone will vary slightly in thickness and you won't be able to adjust accordingly. The support on the tile is now point loaded on the buckshot. If the buckshot rusts, expect discoloration of your grout lines and possible spots onyour granite. You are also lucky that the buckshot did not fall over taped backer joinsts, someone else may not be. The multi layering of ply is needed to support the stone. I wish you luck with your installation. As for lifting the stone, it's actually very easy to do with virtually no mess with a medusa cup, which is a handled suction cup. Chep ones run about $20 and is a good investment given that periodic checking to ensure 100% coverage of thinset is essential.

 

thanks for all the help guys. i ended up having someone install it for me, b/c it was relatively cheap. the installer used 'mastic' instead of thinset. do you guys know how long i should let this stuff sit before i put my sink and cooktop back in place?

thanks

 

mastic under granite and grouted? I don't know, maybe two weeks? What do you think Bob?

 

In 2 weeks the mastic will still be wet under the granite. You will notice what looks like dark spots on the surface of the granite for a while...this is the moisture from the mastic that can't escape. I'd be careful clamping down the sink..any small peices may break if the mastic is still wet.

Just for our own reference...how much did this "installer" charge you?

 

He charged me $400 dollars. I used him b/c he was recommended by two other people that i know.

I had four people come out to give me quotes. They ranged from $350 to $600. I re-decked the countetops myself. I have two very small areas that I did plus the backsplashes. I used a total of only 46 12x12 tiles.

 

Adanac, thankyou. I have given too much bad news out lately. I was going to let tileguybob drop the bomb, but the 2 week comment was to soften the coming blow.

 

It's too bad that these bad installation methods don't fail more often. It could be that this counter will last forever, but it's still the wrong way to do it, and the installer won't learn anything, and do the next job the same way. Depending on where you live, the $400 is about right, so at least he didn't take advantage of you...it's just too bad he didn't read the directions on the pail of mastic . ...the part that says not for natural stone...unless of course he used some product I've never heard of that is made for stone.

 

all of the installers that came out told me ahead of time that they had a minimum charge. that is understandable b/c i do the same with websites i design. as for the mastic... a simple search on the web will show that many people recommend using mastic with granite and marble. all of them do warn about the dry time though. some do warn against using it on tile over 8" b/c of this.

for as the mastic.... i am fine with it. i did some reading on it. the installer actually had the choice of mastic or thinset. i had already purchased the thinset and he said he would rather bring his own mastic b/c he had more faith in it. he knows more about it than me, so i let him do it. he said he has been doing it for years and hasnt' had any complaints. and according to the two people that refferred him, he isn't lying.

thanks for all the advice

 

Just for the record, because he did use mastic does not mean he did it right. Mastic is not for use on stone. I know people do it and some get away with it for awhile, but I pity the poor homeowner when the installer doesn't get away with it, for that is the person who will pay the price. Anyone who reads this thread please do not use mastic under 12" granite, can I be any more specific?

 

Perhaps you could try bold type, new font, and a color DO NOT USE MASTIC WITH STONE OR ANY TILE LARGER THAN 8x8 and ON WALLS ONLY AND IN DRY AREAS ONLY

 

Wish I had found this discussion before I used acrylic mastic with the granite tiles on my kitchen counter. The tiles are the light gray granite that HD was selling for next to nothing and now of course they are all blotchy from the trapped moisture. Will the stains go away over the next few weeks? Is there anything that I might do to speed the process? Thanks,

 

Hard to say if the stains will totally disappear. Blotches caused by moisture will pretty much go away when the setting material dries out, could be weeks with mastic, Any blotches caused by chemical reaction of the stone to the components of the mastic may be permanent. Only time will tell.