Information I Should Have Known About Gypcrete Before Having It Installed

I installed self leveling concrete in the master bathroom (about 7 by 8 feet). It did not come out good with the primary issue being that it was not completely level. I had calculated how much of the SLC I needed to do the job but some of it seeped through holes in the concrete. I did my best to fill all of the holes but SLC will find it’s way through the smallest of holes. I had a situation where the SLC was draining through holes as it was drying, leaving some sloping in places.

For the master bedroom I decided to contract the install of self leveling concrete to third party. I choose to have Koch Mechanical install Gypcrete. Gypcrete is not the same as the concrete product I bought at Lowes for bathroom, some would argue it’s not a concrete product at all. There are a number of things I should have understood about Gypcrete before I had it installed, thankfully non of it’s issues would prevent me from using it.

Gypcrete is a brand name belonging to the Maxxon company. Although proprietary, the name of the product should indicated that it contains a large amount of gypsum. According to the Manufacturer it is superior at dissipating heat vs normal concrete. Thus, the company that installed it for me specializes is installing gypcrete over radiant floor heating.

Gypcrete is installed in a liquid form and can be walked on in few hours, and is completely dries in 30 days. It doesn’t cure like concrete, it just dries. The finished product is like having a floor made of solid chalk. It can be scraped and dented with sharp objects. I don’t know for sure, but it seems like it could be busted up and re-liquified.

Gypecrete absorbs water easily and might react with concrete products. It also isn’t a structural product and can crack easily. For these reason the manufacturer recommends some sort of anti-fracture membrane or barrier between the Gypcrete and thinset. Since I had it installed over a very solid concrete floor (as opposed to a more flexible wood floor) I wasn’t worried about cracks.

Although the thinset I used stated it was ok to use on top of Gypsum, I felt it was a good idea to put some kind of barrier. I put down RedGuard, which is an expensive waterproofing liquid plastic that is rolled on like paint.

I’m happy to report the tile has been installed and there have been no issues with the tile, thinset or gypcrete.

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2 Replies to “Information I Should Have Known About Gypcrete Before Having It Installed”

  1. It also isn’t a structural product and can crack easily. For these reason the manufacturer recommends some sort of anti-fracture membrane or barrier between the Gypcrete and thinset.

    The job I was referring to in the other post had to be framed heavily and 1″ plywood subfloor was used so the (wood) floor and framing would be solid so the gypcrete would not be susceptible to cracking.

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