PSA: How I stopped using plywood underlayment and switched to self-leveling compound on old subfloors

I used to spend hours screwing down 1/4 inch plywood over old hardwood floors to get a flat surface for new flooring. Last year I did a job in an 1890s house in Portland where the floor dipped almost an inch in the middle. After fighting with shims for two days on a single kitchen, I finally tried a bag of self-leveling compound from the local supply house. It cost me about $80 for the bag and primer and took maybe 3 hours total to pour and let cure. Now I use it on any subfloor with more than a 1/4 inch dip over 6 feet. Has anyone else made the switch and found a brand they swear by for deep pours?

3 comments

3 Comments

grant_hart26d ago

Funny enough, I actually tried self-leveler on a crazy sloped floor in my own house once and ended up with a puddle that looked like a melted C-3PO from the ankle down. The stuff is great for that old house wobble if you do the prep right, and I learned the hard way that skipping the mesh is like trusting a wet paper bag to hold your groceries. Abby's dead on about the wood breathing thing too - I had a pour crack right along a nail line because I forgot to prime over the old hardwood properly. Man, nothing makes you feel like a genius quite like watching fifty bucks of leveler turn into a giant terra cotta pot for your kitchen.

abby_wilson5126d ago

That's a good tip but I gotta point something out. You can't just pour self-leveler straight over old hardwood floors, at least not without doing some prep first. The wood will expand and contract with moisture changes and that can crack the leveler or make it pop loose. You need to put down a primer that's made for wood, and even then some pros say you should put down a mesh or reinforcing fabric for anything over a quarter inch deep. Otherwise you're setting yourself up for a big failure down the road when the floor shifts with the seasons. I learned that the hard way on my first pour.

danielr9426d ago

Right because nothing says "problem solved" like pouring a giant concrete pancake on top of a 130 year old house that's been settling crooked since Grover Cleveland was in office. I'm sure that wood floor will just FORGET how to breathe for the sake of your new LVP. You do you, but I'll stick with the plywood and shims where I can actually sleep at night knowing the floor won't turn into a giant jigsaw puzzle crack by next spring.