Mortar Bed Thickness

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Dohc

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How thick is too thick for a mortar bed under a corner tub. We have about 4 inches to the base of the tub and 2 inches to the bottom of the metal supports. The manufacture requires a mortar bed. And I understand the ticker the mortar bed the more shrinkage of the mortar. I feel 4 inches is a lot but should be ok, and better than nothing.

20220718_201610.jpg
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There is only 1/2" space between the drain and the plywood floor. This is part of the reason the tub was installed at this height to allow room to install the drain, without having to cut up the plywood floor and a joist...
20220718_201650.jpg
 

Dohc

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Re-Reading the install instructions (page attached) they suggest 2 to 4 inches. I guess this answers my question.
 

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  • Tub Install Mortar Instructions.pdf
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Reach4

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The word "bed" is troubling. What you have in mind is probably not what you want to do.

Instead, use piles, with space to let the mortar squish.

Also, try this Google search:
"non shrinking" mortar
 

Dohc

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The word "bed" is troubling. What you have in mind is probably not what you want to do.

Instead, use piles, with space to let the mortar squish.

Also, try this Google search:
"non shrinking" mortar
Your correct, "bed" was not the word I should have used. The intent is to place "piles" that will squish out.

2022-07-19 16_23_18-Comfortflo Receiving and Instatllation Information.png
 

Jadnashua

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It's all about the mix of the mortar. What tends to work here is sometimes referred to dry pack or sand mix. This is a very lean mix of cement in about a 4-5:1 ratio of sand:cement mixed wet enough to hold together if you squeeze it (think making a snowball), but not dripping wet.

You can put a sheet of plastic flat on the floor, too. That will help prevent the plywood from sucking moisture out. The mortar needs to cure, and eventually, whatever excess water is in the mix will evaporate.
 

Dohc

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Thank you everyone for your feedback. Here are pictures of the finished install.

PXL_20220728_210958190.jpgPXL_20220728_211019701.jpgPXL_20220728_211057315.jpg

Again, thankyou for your input.
 

Tuttles Revenge

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Pretty sure that every tub that has air jets on the bottom, instructions say not to set them in mortar.
 

Dohc

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Tuttles, I thought the same thing, but reading the instructions and calling the tub mfg, they are very clear, even with air jets, to set in mortar. See above post with image direct from the air jet tub instructions, mortar AND 3 to 5 mil plastic required.

All and all I am happy with the install. Stepping in the tub is like stepping on a rock, and all the air jets work.
 

Tuttles Revenge

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OH I saw the photos and they made me cringe!! But as long as the manufacture made the suggestion, then its on them. Especially with a consult.
 
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