How level should a subfloor be for engineered hardwood?

Author: Karolann Wunsch  |  Last update: Saturday, September 13, 2025

Before you begin installing Envision engineered hardwood flooring the sub-floor must be dry, level and broom swept. The level tolerance is 1/8 + or - over 10'. This tolerance applies to nail down, floating and direct glue down applications.

How level does the subfloor need to be for engineered hardwood?

Ambient temperature and humidity along with subfloor moisture content must be in synch with the moisture content of the wood. Flatness required as follows- 3/16" in 10' or 1/8" in 6'. Floating floors requirements are more stringent, see section 4.4 for more details. Sand high areas and joints.

Can you lay engineered wood on an uneven floor?

Needs to be lifted an re-laid. Engineered boards dot need time to settle. Proper expansion gap is required . If the floor is uneven it must be leveled out prior to installation.

How flat does the subfloor need to be for hardwood?

Most experts agree that the maximum tolerance for a subfloor is 3/16” over a ten-foot span. Any dips or mounds exceeding this measurement need to be addressed before installation.

Does the subfloor have to be perfectly level?

No subfloor is perfectly level, but any signs of unevenness and high or low spots must be remedied. Please follow these requirements: Subfloor unevenness cannot be greater than 3/16 of an inch over a 10-foot span or 1/8 inch over a 6-foot span.

How to Prep Subfloor for Hardwood

What is the tolerance for uneven subfloor?

The acceptable tolerance for subfloor unevenness for laminate flooring is typically 3/16 inch over a 10-foot span. If any areas exceed this tolerance, they will need to be addressed before proceeding with the installation.

What is the flatness tolerance of a subfloor?

The Standard simply defines the required flatness of a concrete subfloor. The subfloor, or 'underfloor' as I like to call it, “shall not deviate more than 3/16 of an inch in ten feet.” Photo 1 shows a ten straight edge being used to gauge the undulation of the floor.

How do you install engineered hardwood flooring on a subfloor?

Glue-Down Installation Over a Concrete Subfloor
  1. Step 1: Set the Expansion Gap. ...
  2. Step 2: Apply the Glue to a Small Area. ...
  3. Step 3: Spread the Glue. ...
  4. Step 4: Place the First Row. ...
  5. Step 5: Tap the Second Row Into Place. ...
  6. Step 7: Continue Installing the Floor. ...
  7. Step 8: Cut the Final Boards to Fit.

How to level a subfloor for hardwood?

Thoroughly vacuum the existing floor, and use a long floor leveler and tape measure to ensure the subfloor is level within 3/16 inch for every 10 feet. You'll need to know how to level a floor: Just sand any high spots and fill the low spots with leveling compound.

How level does the subfloor need to be for LVP?

Use the proper leveling compounds to provide a flat surface – subfloors should be 3/16” in 10' or 1/8”: in 6' – the use of a 6' level can help to determine the flatness of the subfloor. square footage – for areas less than 2500 sq. ft – minimum expansion space is ¼” areas larger than 2500 sq.

What is the subfloor tolerance for engineered wood flooring?

Subfloor conditions

HORIZONTAL / FLAT – Maximum tolerance of 5mm over 3 meter, or 3mm over 2 meter. Sand high areas or joints. If the floor is glued, fill the low areas with a latex additive cement surfacing product with a minimum resistance to compression of 20 000 kPa.

What is the acceptable gap in engineered hardwood floors?

Generally speaking, gaps in a wood floor are normal for boards up to 2¼ inches wide if the gaps close during more humid times of the year. Normal gaps can vary in width, ranging from hairline gaps to the thickness of a quarter.

What is the best flooring to put down on uneven subfloor?

One way to install flooring on uneven floors is to choose a type of flooring that is naturally flexible. This makes carpet one of the most ideal options: it's cheap, easy to install, and very attractive. For only slightly uneven flooring, sturdy materials such as luxury vinyl plank can also be used for full coverage.

How do I know if my subfloor is level?

Check the Level of the Subfloor

To check for small high or low spots that may not even be visible, place a long level or straight pipe on the subfloor. Move it around to different areas and mark any high or low spots you find with a pencil or marker. Most floors will have at least some slight variations.

What is the best subfloor for engineered hardwood floors?

Particle board is made from wood chips, sawdust and resin and is one of the older materials used for subfloors. It's best for engineered hardwood floors, carpet, or luxury vinyl as it doesn't hold nails or staples.

Where do I start laying engineered hardwood floors?

Now let's lay some engineered wood flooring! Starting on a clean subfloor, place spacers between the wall and the planks. Use your spacers to ensure there is a ¼” expansion gap from the wall. Set the first plank in the corner of the room, working from left to right.

How level does a floor need to be for engineered hardwood?

Be careful when laying out the engineered hardwood flooring material. Ensure that joints have appropriate offsets and that you avoid discernable patterns. Check to ensure that the subfloor is flat within a minimum of an eighth inch over a ten-foot span.

Does the subfloor need to be perfectly level?

A subfloor needs to be clean, dry, level and structurally sound. Use a level to determine if the floor is level within 3/16-inch change per 10 feet. Mark any high or low spots with a pencil or marker. If you're gluing the new floor to the subfloor, use a sander to remove oil, wax, paint, adhesives or other materials.

What goes between subfloor and hardwood?

Simply put, underlayment is a layer of material between your subfloor and your floor. While some flooring comes with the underlayment attached, others will require you to install a separate underlayment. Most of the time, underlayment consists of rubber, cork, foam, or felt.

How flat does subfloor need to be for engineered hardwood?

The prep work for laying engineered hardwood flooring varies depending on what's under it, but any subfloor needs to be flat (within 3/16 inch in a 10-foot radius, or 1/8inch in a 6-foot radius); structurally sound and clean; and free of dirt, paint, drywall patch and other contaminates.

Is it better to glue or float an engineered wood floor?

The choice between floating and glue-down installation for an engineered wood floor depends on various factors such as subfloor type, room dimensions, and personal preference. Floating installation offers easier DIY and allows for expansion, while glue-down provides a firmer feel and minimizes movement.

What is the most common method of installing engineered wood floors?

Floating installation: This is the most popular option for a DIY installation since it does not require attaching the new floors directly to the existing subfloor. You'll still need an underlayment. However, once that's installed, you simply glue or snap the planks together to finish the project.

What is the acceptable floor level tolerance?

Just like ceramic tile, wood and resilient flooring require a high degree of flatness that can easily be achieved using a cementitious SLu. Many manufacturers of wood flooring require that the variation in floor flatness be no more than 3/16" in 10' and 1/8" in 6'.

How flat does the subfloor need to be for hardwood reddit?

A common, although by no means universal, rule of thumb is 1/8" in six feet. That is a six foot straight edge or level is used and pivoted in a circle and there is no more than 1/8" of deviation or space under the straight edge at any point.

What is a reasonable flatness tolerance?

For parts under 36” in both width and length, flatness should not exceed ¼”. For parts whose length is between 36” and 72”, the flatness variation should not exceed 75% of the flatness of a 10' sheet for that given width.

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