Tub installation- Mortar bed questions

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Suceress

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My friend is going to get the American Standard Saver tub from Lowes (it's called Ovation at HomeDepot). The installation instructions call for a mortar bed.
Neither of us have ever worked with mortar (although I've poured cement & we've both worked with floor leveling mix-- not the self-leveling kind). I was trying to research & couldn't find any sort of consensus on the best & easiest type to use. I've seen people suggest everything from sandy cement mix to drywall mud to spray foam (spray foam is being ruled out). Looks like it needs to be at least 3/4" to 1" thick although I'm waiting for the mfr to confirm the distance of the tub bottom from the floor.
I checked youtube & some people showed very wet mortar bed, others showed it sandy & moist. We want it to be sturdy but to be forgiving if the tub needs to be pulled/moved.

Putting a moisture barrier down between the plywood and mortar bed is a given. I believe the mfr suggested roofing felt. But should we use some sort of plastic on the bottom of the tub between it and the mortar so it won't stick the tub if the tub needs to be pulled?

I know the pros of the mortar are that it is sturdy but I've heard that if you move the tub too much after placing it, the mortar won't conform to the tub as well as something like drywall mud.

Any particular techniques/tips for a mortar bed?

It's not the brand I would go with for my own house but the one in the store seems pretty sturdy & my friend's fiance LOVES the tub & doesn't want a different one.

TL: DR?
1. Mortar bed:
a) moist & sandy
b) peanutbutter consistency
c) drywall mud
d) other (please specify)

2. Moisture barrier between mortar & floor
a) roofing felt
b) plastic underlayment
c) other (please specify)

3. Barrier between tub & mortar
a) yes
b) no

Any help would be greatly appreciated.
 

Reach4

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Do not use a mortar bed, at least the way I would picture a bed. Search this forum for
index.php
using the search box above.


https://terrylove.com/forums/index.php?threads/fist-tub-install-please-help.84586/ is a useful thread.
 

Suceress

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Reach4- do you mean like the technique of tracing the tub perimeter on the floor and doing 9 piles of mortar inside? Like from this site? https://homeguides.sfgate.com/kind-mortar-use-under-bathtub-97453.html ?

I liked the idea in the thread you linked about using plastic bags over the mortar piles. That would be cheaper & easier than messing with a sheet of plastic, although, I would still want to do roofing felt or some sort of waterproof barrier underneath the mortar piles.

I wonder if drywall mud would be ok for the piles.
 
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Terry

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I have always used piles of mortar mix that will squish out when needed for supporting a tub. The idea was first mentioned in the US on this forum by me. Since that time, other plumbers have copied my idea, and over time even the manufacturers have copied my idea.
I use mortar mix found at any hardware store.
You want the mortar wet and soft. It will harden very quickly anyway.

mortar_mix.jpg
 

Suceress

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Thanks, Terry. Don't suppose you have any pictures of what the mortar looks like at the ideal moisture level? Softer than peanutbutter or about peanutbutter consistency?
There are so many different opinions from people all over so it's hard to find a consensus. The mortar piles idea really sounds like the best idea to me-- sounds the easiest for 1 but also makes sense in that the piles can squish down.
American Standard recommended a particular type & linked to it, but it's not available in my area. I'll have to see if my local hardware store carries the mortar mix. I've seen a lot of the Quickcrete cement, but not the mortar mix (although, I've never looked for it).
 
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