Can You Use Self-levelling Compound On Wood Floors?

Some of them, yes! Designed to create a smooth, flat surface that is level enough to have new flooring fitted over the top, self-levelling compound is a useful substance that makes renovations a whole lot easier than they could be otherwise.

First and foremost, it is imperative that you make sure the product you choose is appropriate for use on wood floors. Not all of them are, so you could end up with a complete disaster if you’re not careful. WFC delves deep into this topic, below:

There are hundreds of different self-levelling products out there, and the applications they can be utilized for should be clearly stated on the packaging – if it isn’t mentioned in the list of suitable materials, then check to see if there is any advice against using that particular product on a wood floor.

If there’s nothing to suggest you’ll have a problem on top of wood, then you’re good to go!

You could always try contacting the manufacturer, checking their website or doing a quick Internet search of the specific product in question if you’re not sure or still a little worried about it.

A how to guide:

Things you will need:

  • Cleaning supplies, a broom and/or a vacuum cleaner
  • Self-levelling compound
  • Polystyrene sill seal
  • A caulking gun
  • Floor levelling compound primer
  • A paint roller and tray
  • Expanded Metal mesh lath and tin snips for cutting (optional)
  • Industrial stapler (with heavy duty, galvanized staples)
  • Bucket and mixing tool (electric drill and mixing attachment recommended)

Once you’ve ascertained whether it’s fine or not to use your particular leveller over wood floors, it’s time to rock and roll! This is going to take you a good couple of hours, so be sure to put aside the whole day, or at the very least an afternoon.

You’ll want to make sure that the entire room, plus the whole of the floor, has been thoroughly cleaned, swept and vacuumed, so there’s nothing that could impede the levelling process.

Then clear out any furniture and make sure there’s nothing left over that could get damaged (or trapped beneath your new floor!)

Now it’s time to prepare the rest of the room, to make sure the self-leveller doesn’t go anywhere you don’t want it to.

First, securely staple some polystyrene sill seal around the room’s entire perimeter, then use caulk to fill in the seam between the sill seal and the floor. 

You should also make a point of covering any large holes like the ones in heating vents or floor drains beforehand. Cut out some cardboard to the appropriate size, use tape to hold it in place, then caulk it to the floor for added security.

Making time to complete all of these preparations will stop the self-leveller from leaking through air conditioning vents, doorways or straight down to the floor below, so don’t be lazy and skip them out unless you want to spend hundreds (or even thousands) of dollars on cleanup!

Once that’s all dried up and ready to work with, you’re going to want to use a floor levelling compound primer on the entirety of the wooden surface – depending on which brand you go for, you might need to mix it with some water in order for it to work properly, so be sure to read the directions and guidelines and get it right.

Of course, you might wish to skip the above step for ease, but given the wood floor is going to be a much more porous base than, say, a slab of concrete, it’s imperative.

The leveler itself contains a great deal of water, so if it’s poured directly onto your floor, the wood will swell up and then shrink back down again as it dries. 

That doesn’t sound like too much of an issue, but you could end up with cracks in your underlayment as a result of the change in size and weight, which might then affect your tiles or whatever kind of flooring you’ve laid on top.

Don’t skip the primer! It can be applied using a paint roller and brush as we’ve recommended, or even with a spray bottle if you’d prefer.

Now that the primer’s all done and dry, In order to provide some added stability, you’re going to want to install some metal lathe over the top.

This adds strength to the levelling concrete once applied, though if you’ve got underfloor heating, you should avoid utilizing metal lathe and contact the heating system’s manufacturer for further guidance.

Ensure the lathe is at least an inch away from your walls, as otherwise it could penetrate the sill sealer. You also want it to be as flat as it possibly can, because you’re trying to level the floor out, not create more disparity in height!

With the lathe in place and offering some structural support, it’s time for the star of the show – your self-levelling compound!

It’s advised you buy more SLC than you think you’re going to need, as pouring slightly too thick – even just by a fraction of an inch – can result in not having enough mixture left for the rest of the floor.

Be sure to keep the bags of leveller away from any moisture and store them on high ground, as you could accidentally ruin it before you’ve even started.

Follow the instructions for mixing up the leveller to the letter – it’s difficult to give a general overview as every product is different, but it should be pretty straightforward.

We would recommend using a big bucket with at least six gallons of capacity, alongside an electric drill with a mixing attachment, as it can get pretty thick quite quickly and becomes difficult to thoroughly stir and combine. 

Top tip: pour the leveler from a lower position, rather than a high one, as this will prevent major splashes or spills.

Should any get on the wall, don’t wipe it off straight away, as it’s likely to turn into an even bigger smudge. It’s much easier to just let it dry and then scrape it off later!

Likewise, wash your buckets as soon as they are empty – but never empty the water out into a drain.