JohnfrWhipple
BATHROOM DESIGN & BUILD
"Never mix mortar outside of the manufacturer's liquid recommendation." - I read this quote this morning on another online forum. Sadly this forum does not have the ignore feature and the poster of this comment is from our local Kerdi Salesman Jim. You can read it here:
What a contradiction to previous posts. I ask you how do you mix thin-set loose to follow the spec's by the sheet membrane makers and not over water the thin-set?
Something has to give. I think it's more reckless to follow the measurements than not. I find that the thin-set is never loose enough when mixed by the book. My experience has shown me that you need a premium sheet membrane that allows any type of thin set. Something like NobleSeal TS, NobleSeal CIS or Laticrete's Hydro Ban Sheet Membrane. And you need to jack up the water ratio.
I have privately tested Latcirete 254 thin-set mixed 20% heavy on the water content. Even with this added water the thin-set passes all my private shear testing tests.
This one point is a subject of much debate. If you call the makers of the sheet membranes they ask for the thin-set to be a little loose. Ask the maker of the thin-set and they say follow the rules. As a builder, tile guy or DIYer - you need to bend one of the rules. Which one do you bend?
I say buy the best thin-set you can. Then mix it a little loose. Not to loose. Depending on the time of year I add between 10-20% more water with my Laticrete 254 mix. I once set a brick over Ditra with this mix. I hung over 1600 ponds of water off of the brick. I tried this same test with AF207 and the brick slide off the substrate still attached to the uncoupling membrane.
Time and again I have run other tests measuring tensile and shear forces. All with the 20% over water mix. Time and again something else failed before the thin-set. When the thin-set did fail it was always at a higher rate that required.
What would happen with a cheap ass thin-set like a VersaBond or non-modifed? I don't know the answer - I never use these cheaper products....
What a contradiction to previous posts. I ask you how do you mix thin-set loose to follow the spec's by the sheet membrane makers and not over water the thin-set?
Something has to give. I think it's more reckless to follow the measurements than not. I find that the thin-set is never loose enough when mixed by the book. My experience has shown me that you need a premium sheet membrane that allows any type of thin set. Something like NobleSeal TS, NobleSeal CIS or Laticrete's Hydro Ban Sheet Membrane. And you need to jack up the water ratio.
I have privately tested Latcirete 254 thin-set mixed 20% heavy on the water content. Even with this added water the thin-set passes all my private shear testing tests.
This one point is a subject of much debate. If you call the makers of the sheet membranes they ask for the thin-set to be a little loose. Ask the maker of the thin-set and they say follow the rules. As a builder, tile guy or DIYer - you need to bend one of the rules. Which one do you bend?
I say buy the best thin-set you can. Then mix it a little loose. Not to loose. Depending on the time of year I add between 10-20% more water with my Laticrete 254 mix. I once set a brick over Ditra with this mix. I hung over 1600 ponds of water off of the brick. I tried this same test with AF207 and the brick slide off the substrate still attached to the uncoupling membrane.
Time and again I have run other tests measuring tensile and shear forces. All with the 20% over water mix. Time and again something else failed before the thin-set. When the thin-set did fail it was always at a higher rate that required.
What would happen with a cheap ass thin-set like a VersaBond or non-modifed? I don't know the answer - I never use these cheaper products....
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