How smooth does a subfloor need to be for laminate?

Author: Mr. Bart Douglas  |  Last update: Saturday, March 15, 2025

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.

How smooth does a floor need to be for laminate?

Before laying the underlay, it's essential to ready the sub-floor. Concrete sub-floors should be completely dry, while wooden ones need to be smooth and level before underlay can be laid.

Can you lay laminate on a slightly uneven floor?

Installing laminate wood floors on an uneven floor requires proper preparation to ensure a smooth finish. Start by identifying the uneven areas using a level. For minor dips or humps, use a floor-leveling compound to even out the surface.

How flat does a floor have to be for laminate?

Floor Flatness

Installing over an uneven subfloor could result in excess movement that might cause gaping and possible breakage. All subfloors require some preparation. Industry standards specify that the surface of the subfloor must be flat to within 3/16” in a 10-ft. radius.

How smooth should subfloor be for vinyl planks?

It's a floating floor. There is no such thing as a perfect subfloor. It is sometimes normal for there to be soft spots. As long as it does not give more than 1/8'' of an inch. If it does then the floor prep was not done properly. The subfloor should be flat 1/8'' in 6'. Which is pretty hard to achieve tbh.

How flat does subfloor need to be for vinyl plank

How level does the subfloor need to be for laminate?

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.

Does floor have to be perfectly level for vinyl plank flooring?

A flat and level floor is key so that the adjoining vinyl plank flooring doesn't have varying heights. It is absolutely essential that the subfloor is completely level.

Can you put laminate directly on a subfloor?

Laminate flooring is designed to be a floating floor that may be installed over virtually any type of sub floor. And by “floating”, we mean that it doesn't need to be nailed or glued to the sub floor.

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 to tell if your floor is level before laying laminate?

To identify and measure minor bumps and dips, lay a long straight edge across the floor, from one wall to the other. Then walk along the edge and look for gaps between it and the floor. You can move the line across the floor and measure these gaps at various points to map out the irregularities.

How much uneven floor is acceptable?

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. Subfloors must not slope more than ½ inch per 6 feet (25 mm per 1.8 m) Subfloors must be structurally sound.

How to fix uneven subfloor for laminate?

Then, depending on the subfloor you're working with, you have several ways to fix it.
  1. Self-Levelling Compound. Self-levelling compounds are polymer-modified cement solutions that transform your subfloor from rough to level. ...
  2. Grinding and Sanding. ...
  3. Use Thick Underlay. ...
  4. Install Plywood.

Why is my laminate floor not laying flat?

If the subfloor has dents or bumps, the laminate won't lay flat, causing that spongy feeling. Eventually, if the subfloor is really uneven, you could break the laminate. Another reason behind the bouncy walk could be an improper installation of underlayment. Buckling also leads to a bouncy floor.

Can you lay laminate on slightly uneven floor?

Before you lay laminate flooring, you need to make sure that the subfloor is level. If the subfloor is uneven, the laminate boards will not lie flat, resulting in gaps and bumps. The good news is that it is possible to level an uneven subfloor before installing laminate flooring.

Why does my laminate floor feel bumpy?

A poorly prepared subfloor is a leading reason for bouncy laminate floors. Uneven surfaces, dips, or gaps beneath the laminate planks can cause the flooring to flex when walked on. Solution: Before installation, ensure the subfloor is smooth, clean, and level.

What happens if you don't stagger laminate flooring?

If you don't stagger the flooring, the floor will be less structurally sound, which increases the risk of damage or separation of the planks. While subjective, not staggering the flooring can result in an odd and repetitive appearance, which can affect a home's cosiness.

How flat does a floor need to be for laminate?

The secret to a perfect laminate floor. The sub-floor has to be absolutely flat - 90% of your worries will then be over. Don't scrimp on the screeding; this is the whole secret to a long lasting trouble free floor. Screeding is a touchy subject but forms part of the job.

How smooth 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.

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.

What goes between subfloor and laminate flooring?

Installing an underlay evens out any imperfections in the subfloor, helping ensure the laminate is level and stable. This extends the lifespan of the flooring because a level and stable subfloor supports the laminate's locking mechanism.

Does subfloor have to be level for laminate?

The subfloor must be level before installing laminate flooring. If the subfloor is leveled, the laminate planks will not lay properly, causing uneven and unsightly floors. If the subfloor is not level, you can use a self-leveling compound to level it out.

Do I need a vapor barrier under laminate?

When laminate flooring is continuously exposed to moisture rising from below, it swells and suffers irreparable damage. A vapour barrier is an effective way to protect your floor.

Can I lay down vinyl flooring if some of the subfloor is slightly unlevel?

In some cases, carpet may be the best flooring choice for uneven floors. The proper procedure for fitting LVT is to ensure that the subfloor is flat before laying your LVT on top.

What are the requirements for a subfloor for vinyl plank flooring?

The subfloor surface must be smooth, flat, dry, clean and solid. Carpet staples or adhesive residue must be removed to ensure proper installation. Subfloor should be flat within a tolerance of 1/8” over a span of 4 feet. Any unevenness over 1/8” must be sanded down or filled with a floor leveler.

How to fix uneven subfloor for vinyl plank?

Depending on the situation, you can either sand down areas of the subfloor that are too high, or install shims beneath the subfloor so that the entire floor is brought up to the same level.

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