Shower Floor

[Gordon Eyre]

One thing about woodworkers many of you are also builders of one sort or another. I need advise with a shower floor. When it was new the floor had a gentle slope to the center where the drain is located. This allowed the water to drain out properly. After about five years the slope became less and less until it now is flat or with a slight rise. I now must squeegee the floor to get the water out. The walls of the shower are faux marble (white on white) and the floor is as well. I do not want to replace the entire shower at this time if I can come up with a fix for the floor. Any ideas or am I destined to replace the whole thing. By the way, the drain pipe can be adjusted up and down just by screwing the flange. The walls of the shower have not moved at all, just the floor from a slight concave to flat or even slightly convex.

[Jim Koepke]

Gordon,

I hate to be the bearer of unwanted news, but your situation could be due to moisture doing something to the floor under the shower.

It could just be foam that has compacted underneath, but it still needs to be checked.

My wife loves to watch Holmes on Homes. Sometimes I will join her.

If you can watch some of these when he is doing bath rooms, you will learn a lot about the possible problems and ways to correct them.

jtk

[Bill ThompsonNM]

+1 for worry about moisture. It might be possible to repair without trashing the walls, but I suspect you might end up with further leaks at the wall floor junction. I wouldn't put it off, you might be creating mold and structural problems already.,

[Kevin Bourque]

I'm a contractor and I do lots of bathrooms.

Do you have a one piece shower pan, or is it a mud & tile job? Either way the pan shouldn't be moving at all. It might be that the joists have sagged under the weight.

[Prashun Patel]

I'm with Kevin. Can't diagnose until we know more about the original construction.

[Brian Elfert]

Wouldn't sagging joists and/or compressed foam underneath typically mean the slope would get greater, not less?

[Kevin Bourque]

Yes it would cause a greater slope, not lesser.

I can't think of anything that would cause a deflection this bad without cracking the floor if it's a mud job, which it sounds like from the description.

[Jim Matthews]

I like the Kerdi system from Schluter (http://www.schluter.com/8_4_kerdi_shower_kit_6551.aspx) - it has a polystyrene substrate that is easy to cut for a tight fit and an impermeable membrane to seal off the works.

It has a built in slope to the pan, and can be tiled for a close match.
As the other posters have indicated, you'll need to pull up the old pan, in any case.

[Ron Natalie]

Faux marbre sounds like one of the preformed shower bases. The good news is that they usually aren't that hard to replace with a like one.

The old way of doing shower floors was to use mud, a membrane, and a double flanged drain to form the flor. Now as Jim points out, Schluter makes a very nice styrofoam/plastic substrate that you can tile right over.

[Gordon Eyre]

I will try to answer all questions with this one post. The manufactured marble pan is one piece and sits on a mud over cement slab. There is no moisture problem as far as I can tell. The pan was put down first and then the walls so in other words the pan is under the sides. The fact that the walls have not moved at all tells me that it is the pan that has straightened out from its original slight convex shape. I figure that I could cut out the pan and then pour something (cement ?? ) in that would go under the walls and could be formed to have a slight convex shape. Am I just asking trouble? Perhaps a quick squeegee after the shower is best until I can do the job right and replace the whole thing.

Thanks for your comments.

[Gordon Eyre]

I like the Kerdi system from Schluter (http://www.schluter.com/8_4_kerdi_shower_kit_6551.aspx) - it has a polystyrene substrate that is easy to cut for a tight fit and an impermeable membrane to seal off the works.

It has a built in slope to the pan, and can be tiled for a close match.
As the other posters have indicated, you'll need to pull up the old pan, in any case.

I will look into this, thanks.

[Bob Vavricka]

Gordon, Ask your question on the John Bridge tile forum. There are a lot of helpful tile and shower people that may have the solution you are looking for.

[Gordon Eyre]

Gordon, Ask your question on the John Bridge tile forum. There are a lot of helpful tile and shower people that may have the solution you are looking for.
Thanks Bob.

[Jack Wilson]

Gordon, I too am a builder, but there are still a lot of unknowns here. Personally, I would just dig in and find out what exactly is there, but I have enough experience behind me, 32 years, that I am usually not afraid to jump in, especially on my own house. If you have the competance and cofidance to tackle this, please keep us posted about it, I will be following, I am slightly intrigued with this situaion. My first thought was water damage/rotted sagging floor.

[David Weaver]

You have to open it up and look. I just redid my bathroom, or at least 2/3rds of it. I had water in places I never expected it to be. You can't tell what you have until you open it and look at it.

[Gordon Eyre]

Gordon, I too am a builder, but there are still a lot of unknowns here. Personally, I would just dig in and find out what exactly is there, but I have enough experience behind me, 32 years, that I am usually not afraid to jump in, especially on my own house. If you have the competance and cofidance to tackle this, please keep us posted about it, I will be following, I am slightly intrigued with this situaion. My first thought was water damage/rotted sagging floor.


You have to open it up and look. I just redid my bathroom, or at least 2/3rds of it. I had water in places I never expected it to be. You can't tell what you have until you open it and look at it.

Most houses in this area are built on a concrete slab, mine included. There are no wooden floors to rot. I really doubt that water is involved. Ground water is also not a problem since I live in the desert and it is very dry. My house has no cracks or movement of walls or floors with the exception of this shower floor. It's as if the built in natural convex shape of the floor just decided to flatten out. The drain portion had to be raised with the flange as this happened. I had to raise it nearly 3/8 of an inch. At first I thought that the drain had dropped but soon learned that the floor had raised. This occurred just in the center as the outside where it meets the wall did not move. Now the shower floor is just about flat with just a slight rise in the center where the drain is.

[Ken Fitzgerald]

Gordon.....I did see St. George on the news a year or two ago when a house washed into the river there didn't I? Some very bad flooding IIRC.

BTW....I used to live in Blanding over 50 years ago......same arid desert climate ......other southern corner of Utah.

[Gordon Eyre]

Gordon.....I did see St. George on the news a year or two ago when a house washed into the river there didn't I? Some very bad flooding IIRC.

BTW....I used to live in Blanding over 50 years ago......same arid desert climate ......other southern corner of Utah.

Your right Ken, I was standing near the bank of the river when the house washed away. It was quite a sight.

[Belinda Barfield]

Haven't worked with cultured marble in several years, but typically shower pans are pretty stout and shouldn't change shape. In my experience, the drain/flange isn't designed to be adjusted once installed. Adjusting can cause damage to the barrier membrane, allowing water to leak. It might be possible to remove the shower pan and slide another one in under your walls but your threshold would probably have to be redone also. I would recommend contacting someone who installs cultured marble and have them take a look.

[Prashun Patel]

Just brainstorming here: is it possible that the walls along one of the dimensions have contracted, squeezing the pan, and therefore causing the center to buckle and raise up?

The Kerdi shower I installed a few years back (I don't believe) required an expansion gap, but perhaps that's required on a pan-style installation?

[Ben Hatcher]

So the real question you are asking is how the CENTER of your shower RAISED UP 3/8", not how did the walls and edges lower 3/8".

The fact that you can adjust the drain line would make me think that the drain is leaking and perhaps causing whatever is under it to somehow swell. I have no idea how a concrete slab would move like that.

[Patrick McCarthy]

So the real question you are asking is how the CENTER of your shower RAISED UP 3/8", not how did the walls and edges lower 3/8".

The fact that you can adjust the drain line would make me think that the drain is leaking and perhaps causing whatever is under it to somehow swell. I have no idea how a concrete slab would move like that.

I would have to agree with this analysis. Seems the drain is leaking into the soil, causing expansion of the soil, and thereby raising the center of the floor of the shower. Either the house is sinking or the shower is elevating . . .

[Gordon Eyre]

So the real question you are asking is how the CENTER of your shower RAISED UP 3/8", not how did the walls and edges lower 3/8".

The fact that you can adjust the drain line would make me think that the drain is leaking and perhaps causing whatever is under it to somehow swell. I have no idea how a concrete slab would move like that.


I would have to agree with this analysis. Seems the drain is leaking into the soil, causing expansion of the soil, and thereby raising the center of the floor of the shower. Either the house is sinking or the shower is elevating . . .

The concrete slab could not rise without causing a crack in the walls or floor by my way of thinking so that leaves the pan deforming. When I raised the drain to meet the pan I was careful to seal it well between the pan and the drain pipe. That was several years ago and the floor of the shower has not raised any since I made that repair. I am just getting fed up with the water not all draining out of the shower so I am thinking about my options. Sounds like I may have to bite the bullet and replace the whole thing. I will probably have a builder come out to give me a quote.

As I mentioned before my house has no cracks in the floor or in the walls so I do not think this is a major problem. The area where I live does not have problems with expanding/contracting soil. I have lived in this house for 15 years and so I am fairly confident that this is just a shower problem and not a house problem. Perhaps it is a manufacturing defect that causes changes to relieve the internal stress of the pan? I am baffled.

[Jim Matthews]

I have to wonder if the pipe below the "P" trap has been forced upwards.

A tree root could exert considerable force, from below.
What will you do for a shower, while making repairs?

At least you're tackling this when the weather is clear.
I had a frost heave near the Gallatin river, north of Yellowstone back in 1988 - twelve tenants without toilets for fifteen days.

When we hauled the porta johns off - the contents were frozen in place.

[Gordon Eyre]

I have to wonder if the pipe below the "P" trap has been forced upwards.

A tree root could exert considerable force, from below.
What will you do for a shower, while making repairs?

At least you're tackling this when the weather is clear.
I had a frost heave near the Gallatin river, north of Yellowstone back in 1988 - twelve tenants without toilets for fifteen days.

When we hauled the porta johns off - the contents were frozen in place.

I have three showers so this will not be a hardship. As to the tree root, the drain pipe did not move it was just the shower floor. Actually I live in an area where it rarely freezes and the weather is clear most days of the year. :)

Thanks for your input.

[Ed Aumiller]

You said earlier "The manufactured marble pan is one piece and sits on a mud over cement slab."
If the pan was originally put on wet mud on top of the cement slab and was not mixed correctly, it will sometimes crumble from walking on the pan...
There will be ever so slight movement everytime it is used. If that happened (crumbling mud) under the pan, it would shift away from where you normally stand in it, which would probably force it towards the center...
Probably can simply replace the pan and seal edges....
Good luck..
Ed

[Shawn Pixley]

There are areas of the US where expansive soils are present. I don't know whether your area has this or not. With frost, expansive soils or other factors such as a leak, it could be that the drain pipe is being forced up and the shower pan is being flexed as a result. The forces on the drain pipe could have subsided dropping the drain down again though the pan didn't return. I have also seen houses settle evenly without cracking walls, tile etc... I am not saying that either of these is the correct diagnosis, but you won't know until you look.

My point here is that you seem fixated on one scenario without proving by exclusion other factors. As others have said, the only way to really know is to open things up and look. You may be right with your original conclusion, but

[Gordon Eyre]

Your right Shawn I need to look. I have simply been trying to use logic as to the cause of the problem and this may defy logic. I thank everyone for your help. Once I cut through the floor there is no turning back. What I was really looking for when I made the original post was how to fix it once I removed the floor.

[ray hampton]

do you plan on having a inspector there to inspect the old work when you remove the shower pan ?

[Gordon Eyre]

do you plan on having a inspector there to inspect the old work when you remove the shower pan ?
I will probably have a contractor do it.