DIY Laminate Flooring Installation Dangers: Plank Gaps

laminate flooring installation plank gaps

Many of you enjoy doing things DIY (Do It Yourself). You have as much fun in a hardware store as some people have in a shoe department. And for those who truly enjoy DIY, the flooring industry has many ways for you to have fun. One of the most poplar segments is installing your own “floating” floors. You buy the tools you need, read the instructions that come with the flooring, and have a good old time. But wait, there’s more. There’s more you need to know that might not be included in the flooring installation instructions, that is.

When you buy a particular product, you’ll have no idea what kind of installation instructions are inside the box. Some manufacturers include instructions that are barely more than pictographs. They are a “universal” language meant to be used in multiple countries with diverse languages. You follow pictures, not words. Needless to say, some things always get lost in “translation.”

Other manufacturers include detailed instructions on how to prep the subfloor, lay out the materials before installation, and install the product. Even clean-up and post-installation maintenance directions are provided.

But the most detailed instructions won’t always tell you everything you need to know. Even reading the warranty won’t necessarily give you complete information.

Here is a case in point. A floor was installed by an individual who loved working around the house. He installed his own floating laminate flooring in an area of his home without heat or air conditioning. He enjoyed it so much that he installed flooring for his relatives and friends, too. So he was surprised when, after several years, his own floor had “issues.” Gaps suddenly appeared between plank joints. He complained to the retailer. They turned the claim into the manufacturer, who in turn asked me to look at the laminate. I have reproduced most of my inspection report here:

I observed end and side gaps up to 3/32” near the tiled entry and at the exterior double doors. The floor is 1/4” out of flat (dips) over 10’ lengthwise in the center of the room. A high pin meter reading of 10% was noted near the exterior doors. A non-invasive moisture meter (scale: 10%-20%) indicated consistent levels of 16%-18% in all areas of the room except for 20% near the exterior doors. A large metal safe that the consumer stated weighs 750 pounds is against one wall. A pool table sits in the center of the room. The flooring is locked in at one bathroom door jamb. When I lifted the molding to check for expansion gaps, I found one 1/4 round nail driven into the flooring. Where I was able to lift the molding, I found expansion gaps of 1/8”-3/8”. Each doorway has a threshold.

The XXXX Flooring Installation guide states:

  • Make sure the subfloor is flat. Any unevenness greater than 2mm (1/16”) over the length of 1 meter (40”) must be smoothed out.
  • XXXX® flooring with underlayment already attached to the flooring plank requires the use of a moisture barrier (included in the XXXX Installation kit) over concrete and wooden subfloors. (This is current policy; required over both concrete & wood.)
  • Under Doorframes: When sawing the planks, ensure that the expansion joint under the door is at least 10mm (3/8”).
  • Ensure that humidity in the room is always at least 50%. Use a humidifier if you need to.

The North American Laminate Flooring Association “Common Complaints” states:

“End gaps can be caused by: locked in floors; unlevel subfloor; low humidity; or an absence of a vapor barrier causing high subfloor moisture. Crackling sounds are due to uneven subfloors; lack of expansion space; or relative humidity/temperature levels that are not within specified limits.

Buckling occurs when there is an insufficient expansion gap around the room perimeters.

Without room to expand, the floor will push itself up in the center creating a buckle effect. This phenomenon is worsened in rooms without proper climate controls.”

The Laminate Wood Flooring Industry guidelines for floating floors states that: “floating floors must move freely. Nothing should impinge this movement. Objects weighing more than 250 pounds are prohibited.”


It is my opinion that the gaps are due to humidity fluctuations beyond accepted limits as well as site/installation-related causes as indicated above. No manufacturing responsibility exists.

Glenn Revere IICRC #113098

So what happened here? Mr. Fix-it ignored several steps that are clearly spelled out in the installation instructions. He didn’t test the subfloor (concrete) for moisture. He didn’t use a moisture barrier. The subfloor was not flat enough to meet tolerance. The room didn’t have HVAC controls. He “locked down” the flooring by not undercutting the door jambs and nailing through the molding into the laminate. AND (this is not in any written material from the manufacturer) he put a 750 pound safe on the floor! Even if all of the other above-listed problems had been avoided, the safe is so heavy that it alone is enough to cause the installation to fail! The weight of the safe pushes the laminate into the subfloor and prevents the flooring from “floating.”

How was he to know about prohibited heavy objects? The information is out there. But, as the old saying goes, “You won’t see what you are not looking for.” You must perform your due diligence and learn as much as you can. In all honesty, professional installers could have warned him about safe’s weight only if the installers were aware that a heavy object would go in the room after they left the job site. Then they could have warned the consumer that an iron safe placed on the laminate would harm the installation.

So, enjoy your DIY projects. But don’t assume anything. Ask questions. Explore the information that’s available on the Internet. Maybe join a chatroom for wannabe flooring installers. And, good luck!

Who is Glenn Revere?

Glenn Revere has been a carpet expert since 1973. He’s a certified flooring inspector and the author of All About Carpets, the only book written to protect and inform you about your carpet choices, from carpet buying and carpet warranties to carpet care and maintenance. He is also a consumer education blogger for The Huffington Post. You can find him on FacebookGoogle+ and Twitter.


Photo: Glenn Revere

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