Granite Tile Subfloor And Mortar

BlueCrabContrct

All-

I've got to put a bid in on a rather small granite tile floor. Size of the project aside, what have you all used for subfloor and mortar when working in granite floor applications? thanks in advance.

thom

Since I build on slabs, I tend to use concrete as a sub floor. You've got to give more information before getting a meaningful answer.

Current framing and sub floor.
Is the floor rigid or does it bounce?

Norrrrrrrrrrrrm

If the substrate is plywood, I use hardi. When using natural stone I use white thin-sets so the dyes don't bleed through the porous material. I also use screws to hold the cbu down better that nails.

__________________
Norman Sharp
http://www.sharpimprovements.com

neolitic

The customer's fantasy will
be a nightmare if the floor
doesn't pass the Deflecto!
http://www.johnbridge.com/vbulletin/deflecto.pl
You can't put marble just any where,
simply because they want it.

__________________
Put your location in your profile!
(Sorry....it seems there really are dumb questions)

kevjob

we usually add min. 1/2 inch ply then ditra then medium bed mortar if the structure is up to par.

__________________
Kevin
Basement Finishing Highlands Ranch Colorado
Littleton Colorado, Basement Remodeling
Kitchen Remodeling Denver

Bud Cline

Blue,

"Size of the project aside"... don't get it.

A natural stone floor installation requires a structure twice as strong as that required for a ceramic tile installation. The deflection rating of the floor structure is what needs to be addressed. Ceramic tile requires L/360 while natural stone requires L/720. All of these calculations depend on how the structure is assembled to begin with.

What size are the floor joists?
What style are the floor joists?
What species are the floor joists?
What is the spacing of the floor joists? (16" 19.2" 24" etc.)
What is the unsupported span of the floor joists?
What is the subfloor covering made of?
How thick is the subfloor material?

Determine the answers to some of these questions then use the "DeflectoMeter" at the Bridge website to do a quick determination as to whether or not the structure is suitable for natural stone.