Moisture reduction

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highup

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I'm going to be installing carpet in a room that was made from 2/3 of a garage. The garage was sectioned off, many years ago and has been used for a craft room for probably 20 years or more. The lady teaches crafts and has tons of storage along the walls and cabinets. In the center resides a couple of long tables with chairs for the occasion when she is teaching a class.
I don't believe she teaches classes on a regular basis, so maybe a couple of times a month if I had to guess. I can't imagine more than four to six ladies at a time.
Anyway, I was first requested to install a vinyl product of some sort. It currently has low profile carpet that has been in there for literally eons. Maybe 20 years?
The carpet wear was not really all that bad, just packed down a little bit like any cheap commercial carpet.
She decided on carpet something similar to what was there and so that's what was ordered.
I think it would be great to reduce the moisture in the room by sealing the concrete somewhat before installing the carpet.
Here's the stats.
The room is 14 x24ish.
The previous pad was most likely rebonded foam. It was quite flat. It was removed so I have no clue how thick it was.
Thick pad would be stupid in this situation considering another stretched in commercial carpet will be installed.
The new carpet is going to be a slightly higher quality and currently everything has been removed from the room.
I'm thinking because of the chairs, and being a commercial type carpet, that a synthetic felt pad maybe 32 oz would be the best situation for this floor. I'm figuring the synthetic pad allows moisture to escape much better than a rebounded foam pad.

Love to hear your thoughts on that.

Personally I think it would be good to put some sort of a sealer down before installing the carpet.
Being that someday could be converted back into a garage by a new owner ........never by this one, I have my concerns about what brand and what type of a topical sealer.
Basically what I'm thinking is that anything applied to the floor would make some reduction in the moisture coming up out of this concrete and through the pad and carpet.
What type of sealer, if any, would you apply to a concrete slab to slow down the moisture emissions in a carpet insulation such as this?
If the product cost $150 I don't think that would scare the customer. That said, I think it would be nice to have a clear type of sealer if there's anything like that available. I need to find a product quickly because the carpet may show up on Thursday. If I need to order something Monday would work.
Basically I'm looking for a clear ceiling that was slow down moisture migration before install the carpeting. I think it would make the room much more comfortable with a little less humidity and not having to run the dehumidifier.

Initially, when she was thinking of installing vinyl or a vinyl plank, I was concerned about moisture in the slab.
The water table is 'relatively' high in this part of town.
Iinitially when looking at the job, I saw a deumidifier in the room and question her about it. So it didn't get turned on very often.
I love for her to get rid of it dehumidifier and put some sort of sealer on the floor to slow down moisture.
I suppose that and drylok brand material might work just fine. I think something clear would be better than something White in color but I'm open to suggestions.
 
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Mark Brown

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Something cheapish and reliable is Planiseal MSP, it is a topical coat barrier for RH up to 99% as long it is not hydrostatic... basically blah blah blah and can be effectively installed on a CSP of 1 although that is not ideal for bonding obviously but it does work.

The reason I recommend that is that when we use it, it has been very effective at reducing moisture transmission from slab. Last one I did was around 97%, it was a green slab that never cured. I ran CC tests on it after the fact and I cannot remember the numbers, but they were astonishing low. Better is the anecdotal stories I can give. We did one ladies basement before a laminate installation because it was exhibiting signs of moisture, alkali salts and musty grossness. Well, we applied the MSP and came back the next day and the quality of the air was insanely different. That was the day I learned to love that product. There are WAY BETTER moisture barriers, but pound for pound, if what you are looking for is something that is easy to use, prep and gives results that would be my choice, hands down.
 

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I was hoping for something that was clear, because someday a new owner might want to tear off the wall and make this area back into a full size garage that said I suppose it could always be skim coated with another cement product to cover up the red. I'll check on that and see if it's possible to get some this week.
The local Habitat ReStore has had a couple of bags of a Tamms product. I'm going to stop down there and take a look. I think it's called Tamoseal. It's in a 50 or 55 lb bag and I think there's a jug of milk that comes with it.
If it's something that is mixed up and applied with a trowel as a skim coat then this would have two benefits.
A, cheap
B, it's already here so no delivery charge.
 

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I called the tech rep for the Tamo seal and he said that the product wasn't really designed for doing the type of thing that I was thinking of.
He said it's intended more for walls but wasn't designed for anything involving hydrostatic pressure.
 

Mark Brown

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the only thing that will work for hydrostatic is going to be epoxy.

The misunderstanding about hydrostatic pressure is that in building envelope it is very rare and most the time isn't what you are trying to overcome.

Hydrostatic pressure is only present only with submerged. Everything else is moisture vapor transmission and not quite the same thing.

When I'm not at work and have the time I have some interacting literature for you.
 

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No if this was hydrostatic pressure that was involved the carpet and pad would have been moldy because it was probably installed 20 years ago. I recall her mentioning that a couple of the cabinets that were particle board had the bases trimmed because of 'poofyness' caused by moisture on the floor level. I think there's a half a dozen of these locker like cabinets that sat on the floor and because of their structure didn't allow moisture trapped underneath there to vent.
The homeowner removed the carpet and the tack strip. I'm going to stop over there today and when I do I'm going to ask him if the tackstrip was rusty and what the carpet and pad looked like.
The location where this house is, is probably 6 blocks by 10 blocks long and the area is relatively flat and all on a sand base. I'm guessing there's a sandstone base under the area somewhere and it keeps the water table fairly high.
A friend of mine lived about five blocks away and I recall him doing something for a neighbor and that when he dug a couple of feet down on the backyard the ground was pretty wet.
So no, we're not talking hydrostatic pressure and the need for an epoxy coating, I just like to slow down them vapors that are coming up through the concrete.
Something is better than nothing.
 

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I went with something as better than nothing. UZIN has a product called 414 turbo. It's a concrete strenthener, primer MVR.
They say for an MVR that it needs two coats. I was able to get those on this afternoon. It says up to 7 lb or 95% RH. Not nearly as good as the Mapi. I didn't check on the price and this was quicker to get a hold of.
Ordered it yesterday it showed up today and was 144 bucks. Even though there was no plan to do a moisture test I figured this is better than nothing. It's a commercial carpet and I plan to use 28 Oz synthetic felt pad. I think it's a bit thinner than the 40 oz. For a commercial carpet like this, thinner is better. I recommended the synthetic felt pad because I think it would breathe better if it needed to. The room previously had a nearly identical commercial carpet but they used rebonded foam and that had flattened out.
We could have shot blasted the floor and bought a two and a half gallon container of epoxy for $700.......
......but for this craft room I figured something is better than nothing.
...... And you don't have to ask, yes I vacuumed the floor before rolling it on. 😁 Not going to get fancy on this one since it's only carpet. The previous carpet was in there over 20 years and died a totally natural death.
That's my story and I'm sticking to it. 😉
 
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highup

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Unless somehow this material turns into a slimy goo after the materials covered with carpet. 😁
It's not, trust me.
Curious got the best of me so I wanted to find out how this material behaves in water contact.
I filled a quart paint container with mostly with water then drizzled a tiny bit of this product onto the water and it sunk to the bottom instantly forming little drops that slightly resembled salmon eggs.
There was also a minuscule film left on the water.
Later last night, the water surface had become a bit cloudy and I use a piece of toilet paper to dip into the water and remove the film that was on top. It had crystallized. The top of the film was smooth and the bottom of the film had formed bumpy crystals.
Now that I could see through the water again, I noticed a little bubble on top of each drop that was resting on the bottom. When curing it must have formed some gases that expelled through the top of the drop. In doing so each formed a little chimney.
Here's a couple pictures of the thin crystallized surface film and the little drops that fell to the bottom.
I guess if this stuff can turn hard underwater then it ought to be fine on a dry looking slab of concrete.
I think it's the iso in the polymer that makes it behave this way.
Thats 'iso' as in the Diphenalmethanediisocyanate that made that happen.
Hey, I'm a floor hack. I have no clue what I just said. 😁
Still, kind of interesting.
 

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highup

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How else are you going to know?
So what's the next experiment?
Brake fluid, ammonia, chlorine.....
if I die, delete my search history. 😁
No, no more experiments with this stuff. I know what it does now.
I also dipped a 3/8-in piece of plywood into the stuff twice to see what it did. It was just a little piece 1 inch by 3 inches. The plywood is hard enough that I can't put a crease in it with my fingernail. This product can also be applied to plywood, OSB and other stuff be it porous or nonporous.
 

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