Self-leveling concrete over plywood Guide

Pouring self-leveling concrete over the wood subfloor

One way that you can make the concrete easier to work with is by using it over plywood. This provides you with a smooth surface, which makes it easy to apply the concrete. With this blog, you’ll learn how to build a self-leveling concrete slab over plywood.

how to pour self-leveling concrete on a wood floor

Deeply sanitize the wooden floor

Remove any trash, especially anything that protrudes from the ground, such as wood chips or splinters. Use a saw, razor knife, or sander to get rid of them.

Next, carefully clean or vacuum the floor to remove any dust or debris that may have fallen on it. Dust and filth can make the compound less likely to stick to the floor, which could cause issues later.

Use a moist sponge or towel to clean the floors after removing all the dust and debris, and then let them air dry.

Seal all Cracks

The plywood’s end grain is where water penetration is most likely to occur. Fill up any spaces with the painter’s caulk between the plywood, the wall, and the boards. You may also use the caulk to seal any holes or gaps in the plywood that you believe water may have managed to seep through.

Put a sill sealer on the wall bases.

Install a sill sealer using a stapler at the bottom of each wall. When walls expand or compress, a sill sealer helps keep them from crumbling.

Additionally, it stops moisture or water from penetrating the concrete composition.
When the floor has dried, you can trim off any exposed material. 

Prevent the compound from reaching the unwanted area

It would help if you built a barrier or wall to stop the liquid compound from leaking through any drains or openings in your room.

To create a ring around drains, you can use cardboard or plastic sheets, sealing the base to prevent seepage.

Seal The Plywood Well

The primer should then be applied thickly to seal the plywood. The ideal method for applying a thick, uniform coat of primer to the whole surface is using a roller and latex-based paint. Give this a full 24 to 48 hours to dry completely. 

For best results, highlight low areas.

If there are any low areas on the floor, mark them with a marker pen. A laser or long bubble level can be used for this. 

As you pour the compound, be careful to pour into these spots to fill them up and bring them up to the same level as the rest of the floor.

Several buckets should be ready before mixing.

You can swiftly mix many batches of the compound by measuring the necessary amount of water and adding it to each bucket you have.

When not in use, place the mixing extension and drill in a bucket of water to prevent them from drying out between mixes.

Make a pouring strategy by working backward from the region farthest from the entryway. If you are confident in your strategy and have all the necessary resources, you are prepared to start.

Mix and Pour the Compound Quickly but Evenly

Utilizing the drill and adapter, combine the dry compound with the bucket’s specified water. For about 2 minutes, fully combine until the mixture resembles pancake batter in consistency.

Make sure to remove all of the compounds from the bucket’s edges and bottom, and break up any dried clumps.

Do not use more water than is necessary. If the surface of the combination develops a white coating, you have added too much water. Pouring can start after the mixture is even and completely blended.

Pour back and forth while staring at the rear to get a roughly equal coat. After that, smooth the mixture with the gauge rake to get a consistent depth.

Move swiftly back to mixing the second bucket when you have finished pouring the first one.

To guarantee an equal coat, cover the entire surface and use the gauge rake.

Do not stop to try to clean the mixture that you accidentally got on the walls or baseboards.

Instead, give it time to dry before scraping it off. You only have approximately 20 minutes before the compound begins to cure and build up, so you must move quickly.

Lightly Sand

Sand off any high spots and vacuum up the dust after letting the leveler entirely dry. You need not require a glass-smooth surface, but you should be able to trace a straightedge over it without noting any significant gaps.

To find any gaps you may have missed, run a work light over the surface as you inspect it with a straightedge.

Advantages of using self-leveling concrete on a plywood

Use the existing subfloor

Once you remove the existing flooring to reveal the plywood subfloor, you don’t have to remove any extra layers. Follow the installation instructions to prepare the plywood. You don’t have to start a new floor so as to set up a new floor

Simple to do 

Self-leveling concrete is simpler to install, especially for do-it-yourselfers, because leveling does not require shaking because it has a lower viscosity than conventional concrete. No extra equipment has to be rented, and the installation procedures are simple to follow.

Get a new floor faster

Self-leveling plywood with concrete may be installed more quickly than normal concrete.

Your new floor might be ready in hours rather than days once the concrete has been poured because the drying period is often shorter.

Businesses may pour a new base over the course of one night and have it ready for use the next morning.

Save money

Self-leveling concrete may be put in very thin layers so as to reduce cost. This results in less material being used than with ordinary concrete, giving it a more affordable alternative. 

Enjoy a lifetime of durability

It has high compressive strength, so you can depend on it to endure for a long time, whether you use it as an underlayment or on the finished floor.

Precautions for self-leveling over a plywood

Avoid excessive weight

If excessive weight is placed on top, subfloors and all the structural components that support them, such as joists and beams, may become unstable.

Make sure you are adhering to the load restriction when using raised flooring with a crawlspace or basement underneath.

check for uneven floor joists

When self-leveling over a wood subfloor, the joists must be exclusively checked because the floor joists are the like the foundation of the floor, and if not well constructed or reinforced well it will lead to cracking and evenly breaking of the self-leveled floor

How thick can you pour a self-leveler on plywood?

According to most manufacturers, no more than a 1/8″ thick application of self-leveling or floor patch compound should be applied at a time.

This depends on the specific floor leveling product you are using.

To steadily raise the thickness up to 1/2″ thick, you can, however, apply numerous thin layers of the compound, allowing each to cure at the required time.

What are common mistakes to avoid when pouring self-leveling concrete over a wood subfloor?

Answer: One common mistake is insufficient surface preparation. It’s crucial to thoroughly clean and remove any debris or contaminants from the wood subfloor before pouring self-leveling concrete. Inadequate preparation can lead to bonding issues and an uneven finish.


How long does it take for self-leveling concrete to dry and cure over a wood subfloor?

The drying time for self-leveling concrete over a wood subfloor typically ranges from 24 to 72 hours, depending on environmental conditions. However, full curing may take up to 28 days. It’s essential to follow manufacturer recommendations for optimal drying and curing times.


What types of flooring can be installed over self-leveling concrete on a wood subfloor?

Various flooring types can be installed over self-leveling concrete on a wood subfloor, including laminate, engineered hardwood, vinyl, and tile.


Do I need to worry about moisture or noise when using self-leveling concrete on a wood floor?

Moisture control is crucial when using self-leveling concrete over a wood subfloor. Use a moisture barrier to prevent moisture migration. For soundproofing, consider incorporating soundproofing underlayment beneath the flooring to minimize impact and airborne noise.

How can I ensure a smooth, level finish when using self-leveling concrete over a wood subfloor?

Achieving a smooth finish involves proper mixing and pouring techniques. Follow the manufacturer’s instructions for mixing ratios and pour the self-leveling concrete evenly across the subfloor. Use a smoothing tool to eliminate air pockets and ensure a level surface.


What are the signs that a wood subfloor may not be suitable for self-leveling concrete?

Signs that a wood subfloor may not be suitable include excessive deflection or bounce, significant water damage, or structural issues. Before applying self-leveling concrete, assess the subfloor’s structural integrity and address any underlying problems to ensure a successful installation.

michael Morris
michael Morris

Michael Morris is a seasoned professional with extensive experience and expertise in the field of self-leveling concrete, I am thrilled to share my knowledge with you.

Over the past five years, I have developed a deep understanding of the complexities involved in working with self-leveling concrete, and I'm here to provide practical advice and valuable insights for readers and enthusiasts alike.

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