Hi there, I am hoping some of the knowledge on this site can be passed on to me so we get it right the first time.

We have new construction with engineered joists, 5/8" T & G OsB, hydronic in floor heat, 1-1/2" gypcrete (maxxon) with maxxon sealer, then ?? ditra, then 3/4" granite tile as well as thinner marble, travertine in the bath areas and 1/2" mercier engineered hardwood .

I guess the question is how does it look so far? Do we need teh ditra or is there a better product? prova flex??

Any reccomendations on what to do or not to do? We will be getting a professional for the installation but anything more then thinset on plywood is a new concept around here.

we are doing about 2800' so would relly like to get it right the first time. Also reccomendations for a good tile guy in Saskatchewan woudl be great.

Are your joists rated for natural stone? Stone requires a floor that is twice as stiff than what ceramic tile requires.

Sorry, I have no knowledge of gypcrete, but someone else here probably will.

Yes the joists were engineered for the gypcrete and 3/4" granite load.

You are going to need an uncoupling membrane, such as Ditra
Even though Prova is similar to Ditra, I personally don't feel its as good as Ditra. Schluter really stands behind their product with technical support and warranties. I have never seen anything from Prova.

Your gypcrete pour is pretty standard. Hopefully you will be able to find an installer that is familiar with the complete system.

Just remember, you definitely need the uncoupling membrane over gypcrete, especially when its hydronic heating.

Like RC said, uncoupling is a must, but there are several alternatives in that department. You could use a paint on membrane like redgard, or a peel and stick product, or ditra. With Ditra, make sure that your tile setter has installed a few hundred feet of it at the very least, as it could become a disaster if proper materials or methods are not used.

With that size job, you should be able to attract a good tile setter. Try and ask the high end home builders in your area who they hire.