How To Use Self Leveling Concrete.
Oh, my aching back.
That’s all I can really think about as I write this. This morning I had my first every “Self Leveling Concrete” attempt.
The project in question is the concrete floor of our work-in-progress basement bathroom. We had a serious hot-mess in the worst possible ways:
- Out of Level by 3/4″ over 10 feet
- Countless peaks and valleys
- Three different types of concrete from previous trenching and patching
I researched every website I could find on how to use self leveling cement (SLC), and started to get an understanding on what the heck I was supposed to do. The only SLC I could get my hands on was Custom’s Level Quick RS.
All I really knew for sure was, I needed to move fast!
I assure you, I was fast. I mixed and poured four 50lb bags of SLC in 20 minutes flat. It was like a terribly messy crossfit workout that involved buckets, cement, and a power drill.
It was a success. Here’s how it went, in case you have a floor that needs a similar treatment:
Prep The Space
Dam It: SLC moves like pancake batter as it “finds it’s level”. That means you need to corral it, block it, and stop it from going anywhere you don’t want it to go.
I used Gorilla tape to build a dam around the bathroom perimeter, around the existing toilet flange, and in the thresholds.
Prime It: Since our existing floor was such a disaster, there was no way I would skip this step. The primer looks like nonfat milk when it goes on. I didn’t roll it on, I mixed it equal parts with water, dumped it a little at a time on the floor and worked it in every direction with a stiff bristled brush.
The primer dries clear, and kind of shiny, in about 2 hours. I let ours dry overnight since I was so generous with the application.
GATHER THE GOODS
Preparation is key when doing a project where time is of the essence. Each batch of the SLC will begin to set within 10 minutes, so there’s no a lot of wiggle room to dilly dally.
Since I was working alone, I treated this like an assembly line, getting all of my supplies ready to go before the first bag was mixed.
- I had 4 buckets of water ready, each bucket had 5.5 quarts in it.
- My corded drill (not battery operated) with the mixing beater was ready.
- I pre-cut 3 of the 4 bags of SLC, so I didn’t waste time opening the bags in between pours.
- My trowel was in the bathroom near the area I was pouring first.
- Wrist Watch
- Heavy Duty Gloves
The SLC gets mixed with a beater in a bucket of water (5.5 quarts), for a total of two minutes. It becomes apparent at just about the 2 minute mark that it’s all mixed together.
- Drag and dump the first bucket of SLC in the lowest corner of the room.
- Use a trowel to help push the SLC into every nook and cranny you want it to go in.
Once the first batch is down and looking good (which you have 3 minutes to determine), mix the next bucket.
Pour your next pre-measured 5.5 quarts of water into the mixing bucket and get going again.
The second batch of SLC should be poured very near, and feathering into, the first batch. And keep repeating this until you’re done.
Then you get to clean up the very big mess you made- if you’re anything like me.
Rapid Setting SLC will be walkable in 4 hours, and ready to tile on in 12.
It dries with wavy movements of sand, looking like it’s got ridges, but it’s an illusion- the finished result is very flat and smooth.
And that’s it. Now I get to relax, ice my back, and get ready, because over the next few weekends I’m going to be finishing this bathroom of ours.