# Retrofit mud bed for tub



## smellslike$tome (Jun 16, 2008)

Anybody ever done this or have any ideas about how to approach it without tearing the tub out?

I have one wall that is dry wall and a crawl space for access.

I would appreciate it if you would simply pm me on this rather than blabbing to the whole world.


----------



## ZL700 (Dec 8, 2009)

*Foam it*

Why keep it a secret?
I suggest using and injecting 2-part expanding foam, purchase the two canister post-mix kit at a major building supply outlet


----------



## smellslike$tome (Jun 16, 2008)

Yeah well, I get paid, as a plumbing professional, to solve these problems. It was selfish, self interest that prompted me to request not giving the answer to the entire world, so sue me. Since you are not a plumbing professional, I would not expect you to understand.

Btw, of course I had already considered foam but was looking for ideas for a better way. If the foam does not, for whatever reason, give the desired result, requiring the tub ultimately to be pulled and reinstalled properly, good luck getting it out of there after the foam has cured and has a death grip on the tub, floor, stud wall, and whatever else it came in contact with.


----------



## ZL700 (Dec 8, 2009)

Working in a desired field doesn't automatically label a person a professional. I get paid as a professional licensed engineer (PE) to instruct people how to solve problems. 

Good luck with your project, foam is used all the time when fiberglass tubs are installed without a proper mud base, and commonly used after the tub repair company fixes the bottom. You can always pump a slurry of concrete in, but access to equipment may be difficult.


----------



## ROCKSTARPLUMBER (Dec 14, 2008)

I take it that this tub is not sitting on a deck, but rather up in the walls? Where the sheet rock/tile is laying on the lip of the tub at all three walls?


----------



## TheMaster (Jun 12, 2009)

Yeah what kinda tub is it?


----------



## ckoch407 (Sep 30, 2009)

ZL700 said:


> Why keep it a secret?
> I suggest using and injecting 2-part expanding foam, purchase the two canister post-mix kit at a major building supply outlet


Foam voids most manufacturers warranties.


----------



## ILPlumber (Jun 17, 2008)

Just to clarify:

Anyone in the pipe trades is welcome here. Including People who draw the pipes we install. A mech engineer might be handy to have around. Don't ya think....

Thank you!
Matt


----------



## ILPlumber (Jun 17, 2008)

I prefer mortar myself. It's on a crawlspace. Getting it in should be no problem.

Drill handholes and start packin! Work your way from end to end through them. Keep the plugs you drill out for re-installation using small 2 by's to screw them in place.

OBVIOUSLY, Don't drill into the botto of the tub:laughing:


----------



## bartnc37 (Feb 24, 2009)

how bout popping the base trim on the end walls or the back side, again this depends on the access, cut in and push your mud in from the ends with a 2x6 or something similar and then put the base back on. It's like it never happened and if your real lucky the base is some of that nice 6 inch high stuff and you'll have all sorts of room.


----------



## TheMaster (Jun 12, 2009)

If its a tub in an alcove with three walls sitting on it on a crawlspace and I had access to the lenght of the tub by cutting the drywall in the next room thats what I would do.

Then I would send sombody into the crawl space directly under the tub in the dark.....and shine a flashlight from the top to show the helper underneath where all the places our pouring/anchoring cement could run through the floor into the crawlspace preventing us from filling the void under the tub. Slide a piece of plastic sheeting under the tub if you can to keep the wood from swelling up when you pour your cement in. If its exterior grade plywood it shouldn't matter that much if it gets wet once or twice.

Once all that was sealed up tight I would use 2x4 to build a form to hold my anchoring cement in place and keep it from running into the walls on both ends and the lenght...the apron of the tub will act as a form also.

Now your ready to mix up your anchoring cement and pour it into the mold. It runs almost like water so all you will need to do is pour it and it will spread itself.

Let it set for a week if you can before letting anyone step into it of ya can. It will be solid as a rock.


----------



## stillaround (Mar 11, 2009)

Smells..pm's are not as much fun...I like a plastic barrier between the mortar/sand mix/ even concrete and tub.( I know its already in there ) Is there any way to lift the tub a little even to get the squish??

I know how to set tubs..hello world..do you hear me?


----------



## ZL700 (Dec 8, 2009)

ckoch407 said:


> Foam voids most manufacturers warranties.


What? Fiberglass tubs for one are foamed, and if it's steel or cast by chance they wouldn't take that stance. 

Someone better tell the manufacturers authorized service centers to stop using foam! Just kidding, ever seen the underside of a spa?... Foam


----------



## stillaround (Mar 11, 2009)

ZL700 said:


> What? Fiberglass tubs for one are foamed, and if it's steel or cast by chance they wouldn't take that stance.
> 
> Someone better tell the manufacturers authorized service centers to stop using foam! Just kidding, ever seen the underside of a spa?... Foam


 I am not bragging ( maybe a little) tubs and setting whirlpools was always a problem till I finally said to all the contractors...stop. This is how we are going to do it. Tile man makes 2 trips.I tried foam a couple times...once it lifted the tub because I wasnt aware it would do that.....it seems so cheesy...especially after you set one in mud with a plastic barrier and stand in that sucker and jump...hooyah.


----------



## ckoch407 (Sep 30, 2009)

ZL700 said:


> What? Fiberglass tubs for one are foamed, and if it's steel or cast by chance they wouldn't take that stance.
> 
> Someone better tell the manufacturers authorized service centers to stop using foam! Just kidding, ever seen the underside of a spa?... Foam


Only speaking from experience. I know its done every day but if you read their literature or try to make a claim when its not installed by their specs they will not honor it. I used to do new construction working for someone else who did several thousand houses a year. Thousands of tubs were foamed until a claim had to be made and they denied it because of foam. From that day forward not one tub was foamed.


----------



## ZL700 (Dec 8, 2009)

No doubt mortor is the way to go, but this one is installed and finished.


----------



## TheMaster (Jun 12, 2009)

ZL700 sounds like a brand of foam to me:laughing: Foam or mortar..either can be effective or a failure depending on the applicant.


----------



## smellslike$tome (Jun 16, 2008)

stillaround said:


> Smells..pm's are not as much fun...I like a plastic barrier between the mortar/sand mix/ even concrete and tub.( I know its already in there ) Is there any way to lift the tub a little even to get the squish??
> 
> I know how to set tubs..hello world..do you hear me?


This is the main problem as I see it, without the "squish", you haven't done anything. Producing the "squish" on an already installed and finished tub is what I haven't figured out how to effectively do.


----------



## TheMaster (Jun 12, 2009)

smellslike$tome said:


> This is the main problem as I see it, without the "squish", you haven't done anything. Producing the "squish" on an already installed and finished tub is what I haven't figured out how to effectively do.


If you use a flowing mixture of anchoring cement and fill up the space under the tub you dont need a "squish". The cement will fill up the void and as you pour it to the top of your 2x4 form....thats about 3.5" deep on a typical 2x4 laid on its edge.


----------



## stillaround (Mar 11, 2009)

TheMaster said:


> If you use a flowing mixture of anchoring cement and fill up the space under the tub you dont need a "squish". The cement will fill up the void and as you pour it to the top of your 2x4 form....thats about 3.5" deep on a typical 2x4 laid on its edge.


 This is true except for shrinkage...might leave 1/8" or so ...but thats not bad. Ive poured runny mud but its a bit messy and sometimes hard to properly due with a 5 gal bucket...probably the way to go.


----------



## TheMaster (Jun 12, 2009)

stillaround said:


> This is true except for shrinkage...might leave 1/8" or so ...but thats not bad. Ive poured runny mud but its a bit messy and sometimes hard to properly due with a 5 gal bucket...probably the way to go.


Anchoring cement expands alittle as it dries or the stuff I use does. Its expensive too!!! This tub would hafta be worth doin all that to for me to do it...it would be expensive but it would work.


----------



## RealLivePlumber (Jun 22, 2008)

Use non shrink grout


----------



## njoy plumbing (May 19, 2009)

stillaround said:


> I am not bragging ( maybe a little) tubs and setting whirlpools was always a problem till I finally said to all the contractors...stop. This is how we are going to do it. Tile man makes 2 trips.I tried foam a couple times...once it lifted the tub because I wasnt aware it would do that.....it seems so cheesy...especially after you set one in mud with a plastic barrier and stand in that sucker and jump...hooyah.


 Check modern plumbing thread. Slow expanding foam does not, I repeat does not lift tubs or bases. Spend hours slapping in your mud base, I'll install my foam and then lightly silicone my drain in.:yes::laughing:


----------



## stillaround (Mar 11, 2009)

njoy plumbing said:


> Check modern plumbing thread. Slow expanding foam does not, I repeat does not lift tubs or bases. Spend hours slapping in your mud base, I'll install my foam and then lightly silicone my drain in.:yes::laughing:


 Hours?...dont you *work*..got any muscles??? mix mud 20 minutes..$3.00. Have something other than chicken salad for lunch.....then lightly do your drain. I repeat. Hooyah.


----------



## njoy plumbing (May 19, 2009)

stillaround said:


> Hours?...dont you *work*..got any muscles??? mix mud 20 minutes..$3.00. Have something other than chicken salad for lunch.....then lightly do your drain. I repeat. Hooyah.


 Not sure, always do it the easy way. I'm an old man that likes to learn new things. yippy ki yay big guy.:whistling2:


----------



## stillaround (Mar 11, 2009)

njoy plumbing said:


> Not sure, always do it the easy way. I'm an old man that likes to learn new things. yippy ki yay big guy.:whistling2:


Thats what he said in Die Hard before he blew him away...go ahead shoot. 
Foam may have improved...but for that hard solid sound and feel ..its mud bud.:thumbsup::yes:
Old?? I'm 57 in October...
Oh, Canada...you need to conserve some strength because its so cold.........how much does that stuff cost....and is it solid?


----------

