Plaster of Paris Toilet Base -- Who Uses It?

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WJcandee

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I'm curious as to the geographic regions in which the plaster of paris toilet base is popular.

When I was first installing my new Totos, the prick at the local Ace Hardware (idiot) gave me a whole lecture on how you needed plaster of paris to install a toilet. Having been participating in this forum, and having read the Toto instructions, and having seen videos from places like the Home Depot on how to install a toilet, I knew that this was total crap. And yet he mockingly told me that without plaster, I wasn't properly "setting" the toilet.

When talking to the very-knowledgeable guy from the highly-successful local plumber I have started to use recently (my previous trusted guy seems to be exiting the business, or at least he is rarely-available, so ta-ta), he mentioned that he uses the plaster of paris method to "set" a toilet. (My previous guy said that they did so as well, but at least allowed that many people didn't do so.)

According to the new guy, the plaster of paris gives you a stable base for the thing, it never rocks, once you put it in you don't have to come back, and it's actually easier to remove, with less potential damage to the porcelain, if you do need to remove it, than using caulk. His main point seemed to be that the method compensated for irregularities in the toilet and in the floor. I asked him if he installed a lot of AS toilets. "Huh?" Never mind.

Then came the condescending slam: "Let us know if you need one re-installed correctly." Funny, we seemed to have been getting along famously until that point, but he wasn't going to get away with that. Upon further discussion, we agreed to disagree. But geez.

I pointed out that Long Island seemed to be the only place in the country that I was aware of where this "make a plaster of paris base" procedure was regularly in use. Indeed, when I replaced the three toilets I have replaced, I have had to chip away the old stuff. Plaster of paris seemed an odd choice of material, as well, but that is the term every guy has used, along with the somewhat-archaic concept of "setting" a toilet.

Anyway, is there anywhere else in the East, the West, the Mountains or the Central States where this method is popular? Is it some kind of old-timey New England thing? I'm curious to know.

On a separate subject, nobody on Long Island has the slightest idea what an air gap or a high loop is on a dishwasher installation. Not the installer. Not the plumbers. We just went through this last week, and I was plenty surprised. Glad my kitchen drain is running well...
 
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DougB

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That's interesting - I recently demo'ed my master bath (1950 - Minneapolis) and I had to chip out this strange material under the toilet. Now that you bring it up - it must have been plaster.
 

joemcl

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I have been in the trade over 25 yrs. just outside of philly, and have never seen this.
 

JohnjH2o1

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I have been in then pratcice trade over 25 yrs. just outside of philly, and have never seen this.

Before your time it was a common practice to use plaster of paris. Some were set with a mixture of plaster and plumbers putty.

John
 

Gary Swart

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The previous post sort of validates my thinking that this was used in the days before the caulking that we use today was invented.
 

Terry

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I have never used plaster to set a bowl.
That would be a tough one if it ever needed to be removed for any reason.

 
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JohnjH2o1

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Keep in mind that many of the toilets set in plaster were 4 bolt bowls that were set on lead pipe without a flange and screwed to the floor with closet screws.

John
 

WJcandee

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I have never used plaster to set a bowl.

Good enough for me.

That would be a tough one if it ever needed to be removed for any reason.

The plumber claimed actually that it made removal easier, which I am here to tell you it doesn't. However, having removed three that had been installed that way, you kind of just rock it gently from side to side and it more-or-less frees itself, more-or-less without damaging itself, then you can lift it out. It's a heck of a deterrent to pulling it back up to double-check or fix something, however. It also left a delightful discoloration on a wood floor.

On one of the 1950s AS toilets, they had actually set the tank in plaster between the tank and bowl, which I discovered when I went to replace the flush valve last year. I guess that was their way of keeping it from rocking. I just chipped it all out, replaced the flush valve, and mounted the tank the way I assume that God and American Standard intended. Turns out that with a decent tank to bowl set and a little trial and error, I was able to get the tank mounted very nicely and very firmly without the need for any schmutz in between.
 
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hboogz

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When I first heard of using plaster, I immediately thought something was not quite right. But, after hearing and seeing several guys using plaster, I think it may be something that's been going on long time. I have seen those plastic shims at HD recently, but have never seen anyone use those.

Disclaimer: I'm not a plumber, but a very active DIY homeowner.
 

Gary Swart

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Shims are only used when a toilet is installed on an uneven floor so it will set level and be solid. The plastic door shims are ideal for this purpose, but other things can be used. Regardless of the material used for shimming, the job is finished with a bead of caulking around the toilet. All toilets based should be caulked anyway, but when shims are used, the caulk serves a triple purpose. The first is to anchor the toilet firmly, the second is to prevent spilled water from getting under the toilet, and the third conceals the shims.
 

hboogz

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Just to confirm with the pros -- is this the caulk that's used ?

pACE3-12920883enh-z8.jpg0007079818101_500X500.jpg
 

Gary Swart

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Don't use silicone. Silicone is very difficult to remove when you need to pull the toilet up. The latex Dap is a good product. You can get it in plastic tubes than don't require a caulking gun. Apply a thin bead and use a wet finger to smooth it out. Water clean-up. Other brands work well too, just be sure it's latex base.
 

Reach4

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Don't use silicone. Silicone is very difficult to remove when you need to pull the toilet up. The latex Dap is a good product. You can get it in plastic tubes than don't require a caulking gun. Apply a thin bead and use a wet finger to smooth it out. Water clean-up. Other brands work well too, just be sure it's latex base.

Is the wet finger also the method of choice with PolySeamSeal?
 

Rich C

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I’m from long island and when I asked a plumber he said if the wax seal leaked the plaster of Paris would soften and let the water leak out
 

Lzyby57

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I’m from long island and when I asked a plumber he said if the wax seal leaked the plaster of Paris would soften and let the water leak out
That is what DAP told me when I asked a question about using it on my toilet. I have a 3/4in gap and they said it will break down in water, but I’m not sure if I can put that much caulk at the bottom to fill my 3/4 gap
 

Reach4

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That is what DAP told me when I asked a question about using it on my toilet. I have a 3/4in gap and they said it will break down in water, but I’m not sure if I can put that much caulk at the bottom to fill my 3/4 gap
I had figured you meant the flange top sat 3/4 higher than the floor. But no, you have a gap, and your toilet flange top sits maybe 1-1/2 inch higher than the floor.

Getting that toilet flange fixed would be the deal. Got a picture of that flange?

If you really want to shim the toilet up that high, then some special shims would be called for. Or get a riser. A marble and granite shop might be able to make one for you, probably using a plastic material.
https://www.vitalitymedical.com/medway-easy-toilet-riser.html offers a 2 inch riser. You would like to have maybe a 1 inch riser. Gonna look a bit hokey probably.
 

Lzyby57

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I had figured you meant the flange top sat 3/4 higher than the floor. But no, you have a gap, and your toilet flange top sits maybe 1-1/2 inch higher than the floor.

Getting that toilet flange fixed would be the deal. Got a picture of that flange?

If you really want to shim the toilet up that high, then some special shims would be called for. Or get a riser. A marble and granite shop might be able to make one for you, probably using a plastic material.
https://www.vitalitymedical.com/medway-easy-toilet-riser.html offers a 2 inch riser. You would like to have maybe a 1 inch riser. Gonna look a bit hokey probably.
Hey Reach4. My gap from the toilet to the floor is 3/4in because I didn’t use a wax ring I used a product called better than a wax ring bc I was trying to avoid the gap being any higher. With just the gap of 3/4, do you think I could use the polyseamseal or my next idea was putting the plaster down and then going over that with silicone or the seal to make it water proof. Thanks your your help.
 
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