Common Problems

What Can Happen, Why It Happens & What You Can Do About It.

White Line Syndrome

What It Means: White lines appear on the board edges.

Likely Causes: This is due to finish stretching as the flooring gaps. Typically this means there was improper acclimation before install, sealer was not applied before the urethane finish or humidity levels in the environment dropped excessively.

Solution: Minor cases may dissipate within a season or two. Sever cases may need a recoat or a complete re-sand. Always try and regulate humidity levels in your home.

Gapping in the Floor (Old Floors)

What It Means: Small to large gaps start to show between the floor boards in older floors.

Likely Causes: This typically results from an expansion and contraction of a solid pine subloor,  using 8d nails as fasteners, many years of dirt that has gotten in the gaps or settling of the foundation over the years.

Solution: Virtually all old floors have gapping; it’s part of their character. Wood filler is usually not an option because it will break out and ruin the look in a few months’ time.

Gapping in the Floor (New Floor)

What It Means: Small to large gaps start to show between the floor boards in newer floors.

Likely Causes: This is generally caused by improper acclimation, relative humidity levels in the environment dropped excessively during dry, winter months or small areas may have gotten excessively wet and dried out.

Solution: Minor gapping is to be expected during the dry, winter months. Excessive gapping due to improper acclimation has no easy fix. Contact your installer. Always try and regulate relative humidity levels in your home.

Cupping in the Floor

What It Means: Cupping occurs when the wood swells and pushes the board edges up, causing a cupped look.

Likely Causes: Cupping may result from improper acclimation, relative humidity levels in the environment increased excessively or the subfloor has excessive moisture in it.

Solution: If cupping occurs due to the environment’s excessive relative humidity levels, take steps to decrease the humidity. Most often this means turning on the air conditioner. If due to a “wet” subfloor, find the cause of the moisture and fix the problem. Most often this can be fixed by installing a dehumidifier in the basement. Crawl spaces may need special attention to keep from causing excessive moisture from wicking into the subfloor. If cupping is due to improper acclimation, a complete re-sand is necessary.

Floor Board Movement (Old Floor)

What It Means:  Floor boards depress when pressure is applied in old floors.

Likely Causes: The movement may be a result of expansion and contraction of solid pine subfloor,  using 8d nails as fasteners or broken tongue and grooves.

Solution: Virtually all old floors have some movement; this is to be expected, especially with old douglas fir floors. Contact your installer for options.

Floor Board Movement (New Floor)

What It Means:  Floor boards depress when pressure is applied in newer floors.

Likely Causes: On new floors, board movement happens when there is poor quality flooring with improper milling, a poor nailing schedule, broken tongue and grooves or if the installer didn’t use tongue and grooves at transitions.

Solution: Minor cases may be spot repaired with epoxy and pin nails. Excessive cases have no easy fix. Contact your installer.


What It Means: Side-bonding occurs when the finish seeps down between boards and glues them together. Side-bonding will usually only be noticeable when relative humidity decreases and the wood floor contracts.

Likely causes: Side-bonding typically occurs with the new water-based finishes due to their high strength and low viscosities. Using a high-quality sealer is advised to prevent side-bonding.

Solution: Regulate relative humidity levels. In excessive cases, a complete re-sand may be necessary. If flooring is permanently gapped and relative humidity levels are stable, your wood floors may not have been properly acclimated. See “Gapping in the Floor (New Floor).”


What It Means: Panelizing refers to when sections of the floor stay tight and create one large gap at its edges, causing a paneled look to the floor.

Likely causes: If panelizing is occurring at the perimeter of the floor, it is likely that wood glue was used for the last few rows and is holding the boards together. If panelizing is occurring throughout the floor, there may be excessive “side-bonding.”

Solution: If panelizing is occurring in a localized area, repairing may be necessary. If it is excessive throughout the floor, a re-sand may be necessary.

  • What our customers have to say…

    “We so appreciate Jim’s professionalism, honesty, respect, eye to detail, and woodworking skill. He is a perfectionist not only with the install but also with the cleanup at the end of each day. Our beautiful new floors have dramatically changed the look of our home and everyone who comes to visit will comment on the change. We are extremely happy with our new floors.”

    Ron and Carol Halverson, West Fargo, ND

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