Hi Andrew
I don't know where you can find all that info at one source but a good thing to have in your library is the Tile,Terrazzo,Marble Assoc. of Canada(TTMAC) handbook,or,the US version...the Tile Council of America (TCA) handbook.
You could also look into Laticrete products for waterproofing and many other specialty systems for tile installations.Get their catalogue.
And Schluter Systems for their membranes and shower drain.
I use only Nu-Heat for heated floors.Most of my work is remodelling...old houses.I've never been involved with a hydronic installation.Schluter's Bekotec system looks like something I'd like to do if it was spec'd by a architect for new construction.
Testing questionable floors for L/360 ? I've never actually done a test with a reading.I usually just walk on it and guess

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When dealing with a floor that has 2x8 joists (or lesser)and the span is too long,I don't consider setting tile on it regardless of the prep methods.Until the span has been decreased by building a wall or adding supports under it.
Sometimes,it's a bit of a gamble I'll admit.For instance,I just completed a polished marble floor where I wanted to add an additional layer of plywood,then the Schluter Ditra uncoupling membrane.But the house had oak floors and nosings and thresholds that I had to set marble flush against.And there were 5 other areas of transitions and about 10 doorways.I understood the customer's desire to have smooth transitions there.Since the floor was built with 2x12's,crossbridging and 3/4" plywood,I decided to go ahead and install Ditra(without the additional layer of plywood that is normally required)and then the 12" marble tiles.I feel confident that the installation will not fail,although,of course,it would have been better to have added the extra layer or a proper reinforced mud bed.Well...I feel confident enough with it the way it is...
