Engineered Bamboo Flooring Installation Problems

bamboo flooring installation

When a wood floor has problems, there are only four causes for those problems: manufacturing, installation, the home’s indoor environment, and maintenance. Sometimes when I look at complaints, I only find one cause relating to the problem. Sometimes I find multiple causes. In today’s Inspection Safari, I share with you an inspection that has complaints with multiple causes.

This engineered bamboo floor was installed throughout a well-maintained two-story inland San Diego home. The main floor had a concrete slab (foundation), while the upstairs subfloor was 1/2” plywood. The flooring was replaced by the retailer after one year because of multiple installation problems. I was asked to inspect the new (replacement) floor. The homeowner complained that the color of the replacement was much darker than the original installation, which she felt was the correct color. She also had concerns regarding the installation. I have reproduced the bulk of my inspection report below:

The floor snaps and squeaks throughout the installation. I measured floor flatness in the living/dining rooms at less than 3/16” over a 10’ span length and width. I found weighted deflection of 1.5 mm in the bath hallway near the entryway wall.

End joint stagger varies from 2 3/4”- 24” throughout the installation. I found planks as short as 1/2” at the room perimeters. I measured overwood on 5 boards at both long and short sides at .006”/.152 mm in the living room.

The long transition strip between the living room wood and the kitchen tile is bowed and cracked. I noticed glue on the wood along the “T” moldings at the kitchen and hall bath. There is no transition molding at either doorway between the living room and entry/dining room.

I checked all room perimeters and door jambs for impingement. Perimeter gaps are a minimum of 1/8”. The base molding is not pressing on the wood floor. Jambs are properly undercut. Flexible caulk was used between the transition moldings and wood at the kitchen and hall bath entries. This removes the perimeter gap and “locks in” the flooring, impeding normal movement.

I used a non-destructive moisture meter and took 30 qualitative readings throughout the installation. The readings ranged from 15%-17% (scale: 10%-20%). The indoor air temperature during the inspection was 87F; RH was 48%.

I could not compare the installed wood color to a store sample or the original installation.


Subfloors must be flat so that the installed wood flooring does not experience deflection. In addition, short end joint stagger and short boards contribute to flooring instability.

Industry standards permit a defect tolerance not to exceed 5% of total installed square footage. The overwood is within this tolerance.

This wood floor is installed in a home without air conditioning or a whole-house dehumidifier. This is considered an uncontrolled environment.

Transition moldings must be placed in all doorways, including the two between the living room/entry/dining area.

The manufacturer’s Installation Instructions for Engineered Bamboo HDF Flooring state:

“Bamboo floors are natural products containing natural variations. Variations in color…exist between samples, pictures, and purchased flooring. They are normal and does not mean that the product is defective.

“Squeaking and clicking noises are the result of interactions among flooring…and subfloors when they move. Limiting the movements of the flooring system usually eliminates most of these noises. Sometimes, it is impossible to eliminate them completely and minor squeaking or clicking noises are to be accepted as normal flooring phenomenon.

“Do not store flooring in uncontrolled environmental conditions. An existing home should have a consistent room temperature of 60F-80F and RH (relative humidity) of 35%-55%. Continual deviation from these conditions will affect the dimensions of flooring, especially bamboo.

“…transition molding is required…at wall openings — with or without door.

“Required expansion gap width is 1/2”. It is required around the perimeter of the floor and between the floor and all vertical obstructions.

“The minimum length of the first and last plank is 12”. If the last plank will be less than 12”, adjust the length of the first plank. Minimum end joint stagger is 6 inches.”

This manufacturer allows perimeter expansion gaps in wet areas (kitchens, baths) to be filled with a silicone based sealant when installing their other floating wood products. However, this engineered bamboo HDF flooring should not be installed in this manner.

It is my opinion that the squeaking floors are 65% installation related and 35% site (environmental) related.

Glenn Revere IICRC #113098

This inspection illustrates the fact that there is more to flooring than selecting a product from store samples. Wood flooring, especially, must be carefully installed according to the manufacturer’s specifications. While there are general guidelines for any installation, each product has its own specifications. There are instruction sheets for the installers in every box of wood. The instructions also explain the necessary indoor environmental conditions and proper maintenance to keep your new floors looking their best. After a proper installation, it is up to you to make sure that your home has a “nurturing” environment for your new wood floors.


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. You can find him on Facebook, Google+ and Twitter.


Photo: “Bamboo Floor” by Shelton Dunning is licensed under CC BY 2.0

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