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Discussion Starter · #1 ·
Hey guys,

I have been working on an addition in my own house for a few months now. I'm doing most of the work including the shower (which I have never done before).

We used a copper pan and I mixed up the dry pack according to a tile friends suggestion - this stuff


It's been sitting for a few months and today when I went to get started; as i swept up some of the loose dust/sand it started coming up. Not really crumbling but just light sweeping stared digging holes in it. Could I have mixed it too dry, or could it have dried out over the last few months? Is there is something I can do to repair it without having to tear it out and start over?

Any help would be huge, thanks!

Here are a couple of pics:





 

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Paul
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How did you mix it? Did you add sand to the mix? Leaving it exposed for months with the HVAC pulling moisture out of it could be the issue.
 

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Paul
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If I questioned the integrity of it at all I'd tear it out and redo it. The cost and time is to little to worry about.
 
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Discussion Starter · #4 ·
How did you mix it? Did you add sand to the mix? Leaving it exposed for months with the HVAC pulling moisture out of it could be the issue.
I just used water, no sand.

If I questioned the integrity of it at all I'd tear it out and redo it. The cost and time is to little to worry about.
You might be right, I just hate doing the same job twice :)
 

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They have it premade in flooring dept, or tile supply, it's 3-4 parts sand, 1 part Portland cement, use enough water in a sprinkle bucket mixing and when you compress it with your hand and stays together it's enough.
Sitting outside can go bad, as it absorbs just enough moisture it can hydrate and still stay powdery, usually it's good for a year.
Curing it keeping moist helps it's compression strength for a few days, put plastic over it to keep from drying, once dry it cannot strengthen due to hydration process being cut short.
 

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It would be best to tear it out and redo it. It looks like it was too dry. The consistency I like is if you can form a solid ball of the floor mud in your palm and it holds shape, but breaks up if you bounce it in your hand. I know this is not the most scientific method but it works. If it is too wet it is also very hard to work. The drain looks low too.
 

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Discussion Starter · #7 ·
Thanks guy,

I have a feeling I mixed it a little dry to begin with and the sitting for a few months just dried it out. I'll redo it... a few hours labor and $25.00 in materials is a cheap insurance policy.

Screw
 

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They have it premade in flooring dept, or tile supply, it's 3-4 parts sand, 1 part Portland cement, use enough water in a sprinkle bucket mixing and when you compress it with your hand and stays together it's enough.
Sitting outside can go bad, as it absorbs just enough moisture it can hydrate and still stay powdery, usually it's good for a year.
Curing it keeping moist helps it's compression strength for a few days, put plastic over it to keep from drying, once dry it cannot strengthen due to hydration process being cut short.
I'm pretty sure sandmix is just that. Maybe a little rich compared to what one would use for a shower...but should do the job.
 

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Paul
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I'm pretty sure sandmix is just that. Maybe a little rich compared to what one would use for a shower...but should do the job.
It is. That's why I asked if he added sand... I think it's 3 or 4:1 out of the bag. I use it pretty much exclusively for shower pans. I add about 20lbs of sand per bag of topping mix though. It only needs to be wet enough to form a ball that will stay together. Basically damp beach sand is the perfect consistency.
 

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It is. That's why I asked if he added sand... I think it's 3 or 4:1 out of the bag. I use it pretty much exclusively for shower pans. I add about 20lbs of sand per bag of topping mix though. It only needs to be wet enough to form a ball that will stay together. Basically damp beach sand is the perfect consistency.
Like building a sand castle
 

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If you're gonna rip it out, which it looks like you should, did you put a pre-slope in under your copper pan? If not, take that out too and install a pre-slope. So many people ignore this vital step, but it's a must for a proper shower. If you have any questions, there is a useful thread over at john bridge.com forum. Just do a search for shower pan install.

And a question, why did you use copper and not plastic? I've never seen copper, but ripped up plenty of lead, and all we use now is plastic.

Good luck!
 

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I would be concerned about the screws that low on the walls. The screws in the cement board should be three inches above the curb height.

Dry pack works well when it's about 5 to 1. Adding sand to sand mix is a good idea since it's about 3-4 to 1 right out of the bag. The added sand will make the mud more porous, which is important in a shower floor. That helps the water find the weep holes. But like someone said, the preslope under the pan is important also.
 
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