Repair of Idaho Quartzite Floor in Shower

[ea]

We are working on a project of repairing damage to a real Idaho quartzite floor in a shower and are looking for advice on how to do the repair with the best chances of long term success. First let me describe the installation and then explain where we need some advice. I apologize, in advance, that the post is so long but I felt it may help in making a recommendation.

The installation consists of a 10'x10' shower room with the floor covered in Idaho quartzite. The stone is irregular in size and shape, some pieces as small as a few inches on a side and some as large as 15". Each piece is between 3/8" and 5/8" thick with most being 1/2". The mortar between the stone looks to be a natural gray color and contains sand. Half of the room, approx. 5'x10', is the actual shower and the remaining half is a drying area. The two areas are separated by a floor-to-ceiling partial glass block wall and an open doorway to the shower area. There is a threshold in the opening between the two areas with a concealed drain under the threshold. The pitch of the floor in the shower area towards the drain is ample and results in quick drainage. Three of the walls are exterior walls made of glass blocks. All the glass block walls seem to be set with the same mortar used on the stone floor. It matches in color and texture. The subfloor consists of 2"x12" with a layer of 3/4" and 1/2" plywood on top. Then there is an 1/8" membrane (liner) followed by 1.25" of what appears to be concrete. We believe the liner is intact because there are no signs of water penetration in the crawl space below. The stone is laid on the concrete. Total floor thickness with subfloor, liner, concrete and stone is approximately 3". The stone floor was laid in 1985. What started us on the project is efflorescence that was showing in the drying area of the room. Gradually it had become chronic and remedial work was needed. Upon thorough investigation, we determined that there were cracks in the mortar between the stone in the shower area that allow water under the stone. The water drifts under the stone and under the threshold and comes up as efflorescence in the drying area. Using cold chisels, we started to remove the mortar between the stones where cracks had formed. This is about a third of the stone and, of course, it is the stone in the center and towards the drain. The mortar we chiseled out was softer than we would have expected, likely due to the water penetration over time. The mortar on the perimeter stone is sound with no cracking and is still very, very hard. For the mortar we took out, we found small channels in the concrete that appear to be erosion of the concrete by the flowing water that had come through the cracks. As we removed the mortar, once two or three sides of a stone were clear of mortar, the stone popped off. There were signs of efflorescent under the stone and so it appears that those stone were only being kept in place by virtue of the tightness of the mortar. One further note on the pitch of the floor being ample in light of the fact that water was able to penetrate the small cracks which you would not expect if the drainage rate was sufficient. We suspect that it was caused by a build-up of hair in the gap between the drain and the underside of the threshold which was not cleared for some time causing slow draining and standing water for longer periods than the pitch would dictate.

Where we are now is this. We have removed all the soft and cracking mortar. All the stone in those areas came off easily. The perimeter stone is still in place with good mortar joints, firmly attached to the concrete bed. There are approximately 50 stone altogether in the shower area. Of those, 35 are still sound and in place. The remaining 15, from the center area to the drain have had the mortar removed and the stone came off too,

My questions are these. (1) Does this sound like a repair is possible as opposed to a demolition of the entire floor and new install? (2) If we go ahead with a repair, how should we go about resetting the stone so it re-adheres to the concrete bed? (4) In reapplying the stone to the concrete, how do we maintain a flush finished floor given that two thirds of the stone still in place and the material used to reapply the removed stone will have some thickness itself? (5) What mortar should we use between the stone? It should be waterproof or at least water resistant and have some adhesives in it to adhere to the stone still in place as well as being able to be colored to match the existing mortar.

The home has another several thousand square feet of the exact same Idaho quartzite installed in the exact same way. It is all holding up very well and looks almost new after all these years. That leads me to believe that generally the installation was done right and that a repair of the shower floor makes sense as opposed to demolition.

Again, sorry for the long post. Thanks for any advice or observations you may have.

Tom.

[Sponsored Links]

[Davestone]

Did the stone you removed show signs of a thinset on it?I would use an unsanded thinset to adhere the stone back with as little height as possible.I would then regrout the stones with a typical sand portland mix.If the mudbed is damaged repair it with the sand portland mix also,with a slurry of portland and water to adhere it to the existing mudbed,using a tampico mud brush to brush it on.3 sand 1 portland.

[ea]

Did the stone you removed show signs of a thinset on it?

The stone came off clean as can be. The only thing on the backside of the stone is some efflorescence.

Thanks.

Tom.

[ea]

I thought I'd post a couple of pictures to show what I'm up against. What I can't figure out is why the base the stone was laid on has the deep crevaces between each stone. You can see from the pictures that it is as if the stone was laid on small islands with deep grooves in the base. In some cases the grout filled these voids and in some cases it didn't. It was these voids that allowed the water to circulate after it penetrated he cracks.

http://i597.photobucket.com/albums/tt56/eap/P8040018.jpg

http://i597.photobucket.com/albums/tt56/eap/P8040017.jpg

[GraniteGirl]

OK - I have a theory:

(Is the house on a water softener, by chance?)

Anyway - here goes:

You mentioned that there is no preslope:

The subfloor consists of 2"x12" with a layer of 3/4" and 1/2" plywood on top. Then there is an 1/8" membrane (liner) followed by 1.25" of what appears to be concrete.

This means that the water that found its way under the stone had nowhere to go but up and out through the grout joints. The stone is too dense to allow vapor transmission in any effective amount, which leads to greater movement of water through the grout joints. The water - being acidic - dissolves away the mortar & grout along the lines of greater moisture migration, hence the little canyons and degraded filling in the joints. 25 Years is a long time for any modern shower :D

The stones themselves are loose because of the pressure built up by the salty deposits that resulted from the movement of the moisture through the mortar.

If I had to suggest a fix:

Redo the entire floor with a moisture barrier over the slope (Kerdi or other surface applied membrane) in stead of under it.

Just my two pennies

[ea]

(Is the house on a water softener, by chance?)

Yes it is! Am I right in assuming that you were suggesting that the salt from the water eroded the base? BTW, the water was tested at the lab and the salt content is in the middle of the acceptable range, post-softener.

Thanks.

Tom.

[ccarlisle]

The water softener exchange of calcium and magnesium ions for sodium ions in your water will prevent the build-up of hard-water salts and soap scum in your fixtures and, in theory, should not affect the pH of your water. Water is normally kept very slightly acidic, like 6.9 or something, sometimes it goes out of whack but that's the way it normally is kept.

Now, if you had developed a leak in your floor pan system and water leached to the drying room side and evaporated, then effloresence would appear because of the water dissolving the salts in the cement. If you had excess sodium in your soft water, then at some point sodium hydroxide would have been formed - probably only minimal amounts but it's action would be equivalent to calcium hydroxide's. So the relevance of hard or soft water is marginal IMO...the only thing I see is, since you have soft water, the efflorescence is less than what you would have had, had you used 'hard' water...but chemically it's a wash.

However, I agree with the problem starting from a non-waterproof construction...having said that, this new technology (e.g. Kerdi) was just a baby back then, so what you have was state-of-the-art - for the period. But not any more. Such is progress!

If you patch the floor, there is no guarantee you won't be patching next year; I would do two things, patch it the best you can and start accumulating the ressources you'll need for a tear-out. You'll buy some time that's about it...

[ea]

If you patch the floor, there is no guarantee you won't be patching next year; I would do two things, patch it the best you can and start accumulating the ressources you'll need for a tear-out. You'll buy some time that's about it...
__________________
Charles

Thanks for the feedback Charles. I plan to fix it the right way now and not do a patch job. I've gone this far, we're doing it right. I'm interested to know what makes you conclude it is a tear-out. I'm all for taking it down to the wood floor and starting from scratch but I can't see why I would do that now. What do you see in the pictures or in my description that suggests it is a tear-out?

Thanks.

Tom.

[ea]

The water softener exchange of calcium and magnesium ions for sodium ions in your water will prevent the build-up of hard-water salts and soap scum in your fixtures and, in theory, should not affect the pH of your water. Water is normally kept very slightly acidic, like 6.9 or something, sometimes it goes out of whack but that's the way it normally is kept.

Now, if you had developed a leak in your floor pan system and water leached to the drying room side and evaporated, then effloresence would appear because of the water dissolving the salts in the cement. If you had excess sodium in your soft water, then at some point sodium hydroxide would have been formed - probably only minimal amounts but it's action would be equivalent to calcium hydroxide's. So the relevance of hard or soft water is marginal IMO...the only thing I see is, since you have soft water, the efflorescence is less than what you would have had, had you used 'hard' water...but chemically it's a wash.


I will be interested to hear what GraniteGirl says now that I have confirmed there is a water softener installed. Her comment (Is the house on a water softener, by chance?) was very interesting. I hope she explains why she said that. It may help me understand how we got to where we are now with this floor.

Thanks.

Tom.

[ea]

Thanks GraniteGirl for the theory. It sure matches our observations at the site. I think you nailed it.

You said:
If I had to suggest a fix:
Redo the entire floor with a moisture barrier over the slope (Kerdi or other surface applied membrane) in stead of under it.


Rather than a complete redo, what do you think of the idea of removing the remainder of the stone, filling in the voids and canyons in the concrete base and re-installing the tile on top with thinset and a Kerdi membrane? Again I am not looking for a quick or inexpensive solution but rather a good long term solution. On the other hand, I see no reason to jack-hammer out a substantial number of cubic feet of concrete if it won't buy us anything. What do you think?

Thanks.

Tom.

[jerrymlr1]

I have that same stone all over my pool deck. If it were me, I would reset the removed stone in Megaflex or Laticrete Platinum Plus. Goop it on and get the thinset to completely fill or overfill the joints. Clean the joints out enough for the grout. Grout with sand and cement, 3 to 1, and use some Anti-Hydro in your grout.
The other option, IMO, is to redo the entire floor, waterproof with Laticrete Hydroban, and set in thinset/mud sandwich. Same thinsets as above. I've never had anything but the best thinsets stick to this stone.

[GraniteGirl]

In my observations of the effects of softened water on stone surfaces (showers, water features etc), I have noticed more etching when compared to surfaces exposed to hard/untreated water. This has by no means been a scientific study and chemistry is not even close to being my strong suit, but these things have always fascinated me. "Get a life!", I can hear you say :D

Anyway - I have done some reading on the subject, but not near enough to even form a decent conclusion, so all I have to go on is basically just a theory. Maybe some bright kid in some geochemistry course will do a study on this for his PhD or something.

Softeners remove the hardness out of water. Hardness caused by minerals such as Calcium, Magnesium, Manganese and Ferrous Iron. This is replaced in an ionization process by Hydrogen, Potassium or Sodium ions. Oxidized Iron will also pass unhindered through the softener. All of these would impact the pH of the water to some degree. It also changes the ionic charge of the water.

With things in nature aiming for equilibrium, I am arguing that the water, once released from the plumbing system then enters the concrete under the shower floor and finds itself in an environment rich in the ions it just lost. Replacement takes place, removing the Calcium, Magnesium and Manganese available in the concrete, resulting in the visible efflorescence (re-depositing of dissolved minerals) and corrosion where the minerals were "poached"

Again - no scientific tests have been done to corroborate this. I would not even know where to begin to try and prove/disprove my theory. It is just what I have observed/deduced.

:nya:

[MDS]

De-ionized or demineralized water was always the industrial equivalent to soft water used in manufacturing, plating, etc. where they very worried about those stray ions in the water. Usually similar concept to the home water softener, but much more efficient. Also used nasty chemicals to recharge, like straight HCl and caustic soda, and water was not certified safe to drink (though it usually was.)

Highly deionized water eats up cement based products almost as bad as a weak acid. I have seen a steady drip of DI water eat a hole through a concrete slab. Granted it took years, but it did it.

There are home softeners now with much better efficiency and newer technologies like reverse osmosis coming on line. And it seems like every McMansion has a system. I wonder if we won't see more of these types of problems in the future.

[ccarlisle]

"Softeners remove the hardness out of water..."

Well, sort of..."Hardness" is not a scientific description of a property of water; rather it alludes to the formation of soap scum in the days when 'soap' was used much more than it is today, a time when bathtub rings, stiff laundry and tea kettles lined with salts were the norm in most family households, to say nothing of plumbing fixtures. But then we found out that sodium salts were more soluble than the equivalent calcium or magnesium salts and so by playing around with the equilibrium of all the cations in water, we arrived at a gram-for-gram replacement of the calcium and magnesium by sodium...Nowadays, of course, soap scum becomes invisible, kettles boil water more efficiently - and plumbing fixtures flow better.

The only thing that is done in water softening systems is we change the calcium for sodium...same amount, but a different salt. Thus, if a water has x grams of 'water hardness' (i.e. the total of all salts) and that that water was "softened" over a water softener system, the 'new' water would still have x grams of 'water hardness '- but now it is sodium salts that don't interfere with laundry or bathing.

So nothing changed apart from the identity of the 'hardness' - but since the cations responsible for 'hard' water were gone, the water is now uh the opposite of hard: "soft". Nothing has been removed...

And as I said, the effects of softening water has no effect on pH or alkalinity. What is more common in water softening systems is a less than perfect alignment of sodium ions on the one hand with calcium, iron and magnesium ions on the other - so you have inefficient systems that just add solids to the water because the resin is old, or depleted. Now just adding solids to the water makes it leave cirlces when the water evaporates. That is probably what you see most ofter, Adriana, as opposed to water being "too hard".

It is all a matter of equilibrium...add excess calcium salts (as you would find in concrete) and the soft water you just used in the shower now becomes 'hard'. Add an alkaline environment or a high level of solids in the water to start off with - and you get precipitation of all kinds of salts within the concrete. Hence efflorescence as the water evaporates...So 2 variables come into play: the degree of softness of the water (ie the efficiency of the set-up) and the total solids (ie where you live in the country).

But my concern over the construction of this shower relates more to the fact that the mortar-bed has leaked. With no preslope, it may be weak plus add to that the continued efflorescence weakening the structure. No-one knows exactly where the leak started...so tearing out a part of it and patching that is just a crap-shoot. It may work, it may not. But chances are that water will find another way of leaking through some other hole or crack.

And to my mind, that's throwing good money after bad...that's' why I suggested a tear-out to redo it with a preslope under the membrane with proper pitch to the drain. But I don't have that kind of money to put into my shower, not many do, therefore a patch might be a stop-gap measure for now while funds are allocated for a redo in the future.

[doitright]

Hi Tom, Welcome! :)

Aside from what may or may not have caused your situation, several points need to be reviewed prior to a suitable repair.

1. How does the current pan liner tie into your glass block walls?

2. Can we see pictures of other walls, curb, drain, etc. ?

3. There is a way to convert your FHA clamp drain with Schluter's new drain adapter. This may or may not be a solution to not make it necessary to tear out your entire pan.

Surface waterproofing is a must. Tyeing into the glass blocks is going to be the biggest challenge, as it will be the weak link with this system.

[ea]

Thanks GraniteGirl, MDS and CCarlisle for the info on the water softener. Do you happen to know the life of resin in a softener?

With no preslope
The floor does have a substantial preslope. We can see it underneath in the joists and subfloor. The water drains quickly and efficiently to the drain. The standing water that pentrated the cracks and enlarged them was due to a hair-clogged drain that was not cleared for some time allowing slow-draining standing water.

The thing that still puzzles me is these large v grooves between the stone. You can see them in the pictures. I'm convinced now that this is not due to damage. It was the way the stone was laid. My theory is that a scratch mortar bed was laid and allowed to cure. Then a setting bed was used where each stone was buttered with a very thick layer of setting mortar and set in place. The entire back of each stone was not buttered so the setting mortar did not ooze out in all cases leaving these grooves on the settng bed. Subsequently the grout did fill some of these voids but not others. This theory explains the grooves as not damage but the result of the way the stone was set. Using a setting bed makes sense because the stone is not unform thickness. Also the grooves are, at most, 1/2" deep which is less than half the overall thickness of the mortar bed. What do you think of this theory?

As to a game plan, I was thinking that if I fill the voids in the bed and then use a thin set application with a Kerdi membrane, I could reset the stone on the existing bed. If I tie the membrane into the glass block walls and the threshold, the shower area will be its own isolated area where cracks that may occur in the future would not have the water pentrate to the subfloor-installed membrane but be stopped just below the stone at the Kerdi membrane in the shower area.

Thanks for all you comments.

Tom.

[doitright]

Hi Tom :)

You are correct about the stone being set in a mortar bed. This is one of the methods that stone masons (and setters) use to compensate while setting unguaged stone. Each piece is set independently, and the mortar bed is "parged", thus allowing room for the mortar to expand while the stone can be beat down into place until it is even with it's neighbor. This is what is leaving the "V" grooves in the mortar joint.

I'm surprised to see the voids under the stone. It's good to see that a bonding cement was used. It is not uncommon that an adhesive is even used in a "wet set" application. This is one of the reasons we have so many exterior deck failures here in the Midwest (besides lacking a drainage mat).

I'm not so sure that the Kerdi will work in your application (while a liquid membrane may after the voids are filled), depending on how smooth you get the base. You'll still need build up the stones, and deal with the drain.

[ccarlisle]

I still think the preslope has something to do with your problem; you said in your first post that, from underneath, the shower floor consists of joists, two layers of plywood, liner, concrete, stone. In that sequence, there is no "preslope", only a slope in the concrete...a "preslope" is a sloped layer of concrete on top of the plywood, and underneath the liner.

So you should have two sloped layers of concrete...the purpose of the preslope is to guide the water on the liner towards the drain. As it is right now, water may penetrate through your concrete and hit the liner - but if the liner is flat on the floor, the water doesn't drain away, it just sits there - so you get soggy concrete.

And soggy conrete will deteriorate in time, as you can see by the efflorescence; the efflorescence is minerals either from your soft water system and/or in the concrete being brought to the surface of the concrete via water evaporation.

I'm no expert on mud showers - but I think that is the gist of the way they are made nowadays; the 'preslope' layer of concrete sits on the plywood and is never intended to get wet. The liner sits on top of the preslope and it's construction allows the water to drain down to the drain. On top of the liner, is another inch or so of concrete (or "mud") that the stone tiles sit on. Properly constructed this way, the mud and the liner get wet but since the liner is sloped, it dries relatively quickly and prevents your problem.

You don't need to demo the drying area, but the area that receives the water - right up to, including and around the drain area - will have to be redone with a sloped, traditional rubber membrane, not Kerdi.

This is not unusual and has been seen before. That preslope is quite important!

[cx]

I'm no expert on mud showers - but I think that is the gist of the way they are made nowadays; the 'preslope' layer of concrete sits on the plywood and is never intended to get wet. The liner sits on top of the preslope and it's construction allows the water to drain down to the drain. On top of the liner, is another inch or so of concrete (or "mud") that the stone tiles sit on. Properly constructed this way, the mud and the liner get wet but since the liner is sloped, it dries relatively quickly and prevents your problem.That's certainly close enough, Charles.

It's pretty impressive just how nasty the area on top of the pan liner can get when there's no pre-slope. Just by the design of the clamping drain there can be no less than a quarter-inch of water standing in the bottom of the mud floor alla time and some of it never gets cycled outa there for years or forever in a continuously used shower.

Pre-slopes are important.

My opinion; worth price charged.

[doitright]

Hi Charles :)

While I agree with most of your information, I'm concerned how a new pan liner is going to tie into the perimeter glass block. I just completed a similar repair on two showers that had no preslope with the best CPE liner on the market. Again the shower failed.

The wrong mix of mud was also used (my job). Concrete is not an acceptable material to use over a pan liner. Water is supposed to permeate through the mud bed, not just the perimeters.

A Schluter drain with flange adapter, or possibly a Noble drain hat can possibly be used in this application. The existing pitch of the surface mud (patched where not deteriorated) will serve as the one and only slope required for a surface waterproofing product.

Hi Tom :)

It would be good to see how the existing liner is tied into the the glass block wall.

[GraniteGirl]

There is a threshold in the opening between the two areas with a concealed drain under the threshold. The pitch of the floor in the shower area towards the drain is ample and results in quick drainage.

It seems like you have a channel drain?

Some pictures of the entire floor, as well as some clarifying the lay-out and drain set-up would be great.

[ccarlisle]

Tom:

"Do you happen to know the life of resin in a softener?"

Well, in theory it's indefinite but n practice it depends on the quality of the resin and it's manufacture and has something to do with how hard your water is. Since it's just an exchange of one ion for another, and if your softener's programmed regeneration is working, then we're talking years and years.

But let me ask you what hardness number do you have and what's the pH of the last t est you did? When was the last time you added salt to it? We have moderately soft water up here so water softeners aren't really required but I'd be interested to know what those numbers are in your case...

[jerrymlr1]

Originally posted by CX
It's pretty impressive just how nasty the area on top of the pan liner can get when there's no pre-slope. Just by the design of the clamping drain there can be no less than a quarter-inch of water standing in the bottom of the mud floor alla time and some of it never gets cycled outa there for years or forever in a continuously used shower.

Pre-slopes are important.
So true. I was quite surprised that a local GC here in Sarasota County actually knew about a preslope and that they are required now. Florida is the capital of lousy tile installations for the last 20 years or so. Even in multi-million $ homes I see denshield, no reinforcing tape of any kind, and mastic used thru out the shower areas.

[ea]

Wow. It's great to see all you pros willing to help today, Sunday. I really appreciate it.

I will provide responses to each post.


I'm surprised to see the voids under the stone. It's good to see that a bonding cement was used. It is not uncommon that an adhesive is even used in a "wet set" application. This is one of the reasons we have so many exterior deck failures here in the Midwest (besides lacking a drainage mat).
John Koessler

Thanks for the confirmation on the method that was used. How could you tell a bonding cement was used?

I'm not so sure that the Kerdi will work in your application (while a liquid membrane may after the voids are filled), depending on how smooth you get the base. You'll still need build up the stones, and deal with the drain.

We should be able to get the base smooth. I agree the drain is a big issue. More to come on that.

Thanks.

Tom.

[ea]

I still think the preslope has something to do with your problem; you said in your first post that, from underneath, the shower floor consists of joists, two layers of plywood, liner, concrete, stone. In that sequence, there is no "preslope", only a slope in the concrete...a "preslope" is a sloped layer of concrete on top of the plywood, and underneath the liner.

So you should have two sloped layers of concrete...the purpose of the preslope is to guide the water on the liner towards the drain. As it is right now, water may penetrate through your concrete and hit the liner - but if the liner is flat on the floor, the water doesn't drain away, it just sits there - so you get soggy concrete.

I'm no expert on mud showers - but I think that is the gist of the way they are made nowadays; the 'preslope' layer of concrete sits on the plywood and is never intended to get wet. The liner sits on top of the preslope and it's construction allows the water to drain down to the drain. On top of the liner, is another inch or so of concrete (or "mud") that the stone tiles sit on. Properly constructed this way, the mud and the liner get wet but since the liner is sloped, it dries relatively quickly and prevents your problem.

You don't need to demo the drying area, but the area that receives the water - right up to, including and around the drain area - will have to be redone with a sloped, traditional rubber membrane, not Kerdi.


Well, as strange as it may seem, here's what was done when it was installed. First, the plywood subfloor has been sloped to the drain on both sides of the drain. We can see this underneath in the crawl space. The membrane was then placed on the sloped plywood subfloor. The first mud bed on the membrane is also sloped. So they accomplished the same double slope effect but in a different way.

More to come on the drain in a subsequent post.

Thanks.

Tom.

[ea]

Hi Tom
It would be good to see how the existing liner is tied into the the glass block wall.
It will be difficult to take some pictures of the tie-in because the construction has more-or-less hidden the details. What I can say is this. All the wall structural elements in this shower are custom-made aluminum structural members made by Kawneer (Alcoa). I am referring to the vertical elements holding up the roof. Other than these structural members, the remainder of the walls, floor-to-ceiling, are glass blocks. I have the custom Kawneer blueprints and it shows a horizontal u-type channel that is mounted on the subfloor at the exterior wall. Integrated into this is provisions to bring the membrane up the wall and then the membrane ties in to the aluminum. The first course of glass blocks sits in this u channel. The integration of the membrane with the aluminum wall members appears to be well-engineered and properly installed.

Thanks.

Tom.

[ea]

It seems like you have a channel drain?

Some pictures of the entire floor, as well as some clarifying the lay-out and drain set-up would be great.


I will take some pictures and post them. It will be a little tough because of the dimensions of the room and the light that floods in through the glass blocks at this time of the day.

At any rate, I believe I have discovered why the efflorescence in the drying area occurred. The more I thought about it, the more it didn't make sense. I have a sloped subfloor (and therefore membrane) where the drying area slopes in to the drain from one side and the subfloor slopes in to the drain from the other side in the shower area. The drain is under the threshold that separates the two areas. I did not want to remove the threshold because I didn't want to deal with the re-installation. Well I bit the bullet and pulled the threshold. It is also custom-made by Kawneer, as I mentioned in an earlier post. It was held in place by a heavy, thick bead of black callk or mastic material and caulked at both sides to some vertical members. Under the threshold is a regular clamping drain. You may recall I mentioned that there has been a standing water problem in the shower due to serious hair buildup above the drain and below the underside of the threshold. The beautifully hidden drain also hides the buildup. Well, the hair (and slim) had also blocked all the weep holes in the drain, major league. Had they not been blocked, I believe I wouldn't have the efflorescence and ....nothing to work on :-)

I believe the thorough cleaning of the inside of the drain has solved that problem. Any future water penetration of the stone and grout now has a path to the drain.

I also believe the mud bed is sound. We have tested it in a number of spots.

Now what I need to do figure out how to re-set all the stone in the shower itself so that it is flush horizontally with the stone that was not removed in the drying area. Unfortunately a couple of large (15" approx) stone span the drying area to the shower area under the threshold and so I dont have much vertical room for an adhesive or thin-set in the shower area to achieve a flush finish that looks good too.

Thanks.

Tom.

[ea]

Well, in theory it's indefinite but n practice it depends on the quality of the resin and it's manufacture and has something to do with how hard your water is. Since it's just an exchange of one ion for another, and if your softener's programmed regeneration is working, then we're talking years and years.

But let me ask you what hardness number do you have and what's the pH of the last t est you did? When was the last time you added salt to it? We have moderately soft water up here so water softeners aren't really required but I'd be interested to know what those numbers are in your case...

The system is manufactured by Water Refining Company and was installed in 1986. It was originally installed due to a white buildup problem at the plumbing fixtures and hardness was assumed to be the culprit. Well the softener did not solve the problem because it was caused by silica which a softener will not remove. The softener was left in place anyway. What's needed to remove silica is reverse osmosis which is a BIG proposition for a whole house system, both cost and space requirements.

We sent the manufacturer the lab results and they said the resin was still fine. The regeneration electronics continues to work correctly. The salt tank holds 5 50 lb bags and is kept at least half full at all times.

As to the lab numbers, I'm glad to list them here but, keep in mind, they are from well water.

Well Water:
pH 7.7 (Standard: 6.5 to 8.5)
Hardness 85 mg/L (Standard: soft is 0-60, moderate is 60 and 120, hard is 120 to 180, very hard is over 180)
Sodium 21 mg/L (recommended max is 100 and over 270 should not be consumed)

Post-Softener:
pH 7.5
Hardeness ND (none detected)
Sodium 51 mg/L

HTH.

Tom

[doitright]

Hi Tom :)

Can you orientate and reset the stones that were removed to their original location? If so, a product such as Mapei's Planicrete W will bond almost paper thin. Bostik's Hydroment Ultra-Set more than likely would be just as effective. All you would need would be a clean surface (both stone and substrate).

[ccarlisle]

Oh I see...a plywood preslope. Boy, sure blows my theory to heck! LOL

I am glad you're closer to the solution!:yipee:

[ea]

Can you orientate and reset the stones that were removed to their original location? If so, a product such as Mapei's Planicrete W will bond almost paper thin. Bostik's Hydroment Ultra-Set more than likely would be just as effective. All you would need would be a clean surface (both stone and substrate).

Yes, John, we labelled each before they were removed and took a picture.

A couple of what I hope are my final questions. Where can the Mapei and Bostik materials be sourced?

What would you recommend for the grout. I do want to match the color. As far as I can tell, the grout that was used was a standard Portland cement and sand. Whatever it is, I would want to match color.

Thanks.

Tom.

[ea]

Well, I settled on the Planicrete W to re-set the stone and will be setting them tomorrow. Thank you John. Now I have to decide what to use as a grout. Any suggestions? I'm thinking Portland and sand. Thanks. Tom.

[doitright]

Hi Tom :)

Portland cement and sand is probably your best bet. It's important that you establish what grade of sand was used, and what the mixing ratio was. It's going to be difficult to get an exact match.