Retrofit Americast mortar bed

Users who are viewing this thread

Nj6964

New Member
Messages
10
Reaction score
0
Points
1
Location
NJ
Hi TL forum! I installed an americast tub 3 years ago in my home and per the instructions did not bed it in mortar. It’s been bothering me ever since because it makes noise when you move around or step in certain spots. I spent forever leveling the ledger, but am now unsure if I needed just one ledger along the 5’ length or 2 more at the front and back along the width.

Either way, I’m considering something a little crazy. The non-drain end of the tub butts up to a wall, which on the other side is a closet. I’m considering how I could open a hole in that closet and push mortar or something under the tub to better support it for the future. Any ideas? I’m thinking I could pack structolite in with a stick of some sort, or maybe spray an expanding foam (sounds scary). Any ideas are much appreciated.

Thanks!!!
Mike
 

Terry

The Plumbing Wizard
Staff member
Messages
29,946
Reaction score
3,460
Points
113
Location
Bothell, Washington
Website
terrylove.com
INSTALLATION - BEDDING MATERIAL (MORTAR, SANDMIX, ETC.) IS ACCEPTABLE SUB FLOOR MUST BE STRUCTURALLY SOUND & FREE OF MOVEMENT / FLEXING

americast-tub-instructions-1.jpg


The recent instructions now allow mortar mix.
I have been doing that for years on tubs, and I had been told it wasn't in the instructions, and I would say, "Just wait!"
Well now most all instructions now mention mortar mix, and almost all plumbers do it now. I always knew it was a good idea when I shared it many years ago.
Back in the 70's plumbers would use foam, and I saw there could be problems with that. I started using piles or ridges of mortar depending on the distance between tub and flooring. It worked much better than the foam. Sometimes you need to think outside the box, and then share your findings.
 
Last edited:

Reach4

Well-Known Member
Messages
38,795
Reaction score
4,413
Points
113
Location
IL
Any ideas? I’m thinking I could pack structolite in with a stick of some sort, or maybe spray an expanding foam (sounds scary). Any ideas are much appreciated.
I am not a pro.

If you had the space, I would consider balls of mortar in plastic sandwich bags. Then shove. Mortar does not need air to harden, and will harden better if it does not dry out.

If the space is smaller, I guess I would shove as I could.

If you are not on a slab, maybe you could super-carefully add a hole or so below, and push material up. Drilling a hole in the tub would be bad, of course.
 

Nj6964

New Member
Messages
10
Reaction score
0
Points
1
Location
NJ
I am not a pro.

If you had the space, I would consider balls of mortar in plastic sandwich bags. Then shove. Mortar does not need air to harden, and will harden better if it does not dry out.

If the space is smaller, I guess I would shove as I could.

If you are not on a slab, maybe you could super-carefully add a hole or so below, and push material up. Drilling a hole in the tub would be bad, of course.
I like this idea, very creative. Is there any problem if the mortar doesn’t get pushed all the way down close to the drain? Based on Terry’s photo above, you don’t need mortar all the way up toward the drain and mortar from 8-40” from one end is OK.

I just found some CAD on American std website, looks like I have between 3/4” - 1 3/4” beneath the tub. Plastic bags may do the trick.

For mortar, is there one that everybody agrees on? structo-lite?
 

Reach4

Well-Known Member
Messages
38,795
Reaction score
4,413
Points
113
Location
IL
I would be thinking Quikrete 60 lb. Mortar Mix. You would not want a plaster. You would not like a light-weight version of something. Light plaster etc is usually used for vertical surfaces. I don't think you would want a fast/rapid set version.

For the holes, I am picturing inserting stiff balls of mortar mix up and to the side as best you can. Maybe finish with one big ball squished up with a plywood piece screwed up from below. Maybe not. My comments are not based on experience.
 

Terry

The Plumbing Wizard
Staff member
Messages
29,946
Reaction score
3,460
Points
113
Location
Bothell, Washington
Website
terrylove.com
The older tubs had more space, and the new ones fit almost to the floor. With those just a little caulking works. With the older tubs with more space, you do need something more.
 

Nj6964

New Member
Messages
10
Reaction score
0
Points
1
Location
NJ
Ok thanks so much everyone. Final plan is to shove small plastic bags full of quikrete mortar under the tub from one end. Maybe trowel some mortar at the end to keep the bags from shifting. Anyone object to that plan?
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks