[This article was originally published in 2008. I have aggregated all of the articles from our Self Leveling project into a new, more complete article with links to each of the individual articles, including the one below. Complete article: How to Pour Self Leveler Over a Large Area]
Our basement floor is approximately 1000 sq. ft. To make pouring the self-leveling underlayment (aka mortar, cement) over the radiant heating wire easier, we divided the room into quarters to make the pours manageable. I couldn’t find good information online about the best way to create temporary barriers, so we improvised. Here’s what we did; and what we learned:
Building Barriers from Spare 2×4 Studs
After laying the heating wire out on the floor, we created barriers just beyond the perimeter of the wire using extra 2×4 studs I had leftover from framing. We then caulked the crease between the 2×4 and the slab on both sides. Caulking on the inner side prevented the self-leveling underlayment (in our case, LevelQuik ES) from running under the board and out into the open area. Caulking on the outer side provided added assurance against leaks, and extra strength to hold the board in place. The outer caulk seal is important since the barrier is prone to being kicked and stepped on during the pour.
After the boards were sealed, we used masking tape “loops” to attach wax paper to the inside of the board (unfortunately, I don’t have a picture of this). We added the wax paper to avoid the SLU sticking to the temporary barrier as it cured. Overall, these temporary barriers proved very successful, although the pour didn’t come out completely level for other reasons. Here’s what we learned about the barriers:
Lessons Learned (Avoid Our Mistakes)
(1) The wax paper idea didn’t work. We left the excess wax paper hanging over the top of the board towards the outside. We ended up stepping on the paper and ripping it away from the board in the middle of the pour. It was impossible to put back into place once the SLU touched the barrier. Fortunately, the SLU tended not to stick the boards, even without wax paper. So, we won’t bother with this step in future pours.
(2) In three places on the barriers the inner caulk seal failed. As a result, the underlayment pooled underneath the barrier in a hollow section. This was most likely due to a poor caulking job on my part. I used a hammer and chisel to remove these pooled sections of mortar pretty easily. But, this lesson proves that the outer seal as an extra precaution is a good idea. Here’s a picture of the pooling:
(3) Pull up the barriers as soon as possible. One barrier that we pulled up immediately after the SLU had set came up without any problems. We used a razor blade to remove some residual caulk. The remaining barriers I left in place for about 30 days. For those barriers, the caulk hardened a bit and created too strong of a bond, causing it to rip some of the wood away when I pulled up the studs. It took considerably longer to clean the edge of the SLU for the next pour area. FWIW, here’s a picture of the scraps.
Other Helpful SLU Articles
What do you think? Was this information useful? What did you use to contain a self-leveling underlayment you poured?