“Do I really have to spend all this extra money on subfloor repair? Or are they just trying to up-sell me?”
It’s a legitimate question.
And considering the amount of extra labor and materials cost that goes into proper subfloor preparation, it often carries a price tag that sometimes equals what you planned to pay just for the flooring product and installation.
But here’s the thing: if there are problems with your subfloor, your brand-new (expensive) flooring installation is going to start failing within two to three years, and sometimes it only takes a few weeks.
Floor failures caused by unresolved subfloor issues
Many of the most common flooring complaints in hard-surface installations are caused by subfloor problems. The subfloor-based flooring complaints that inspectors see most frequently are:
- cupping/curling
- flared edges
- broken edges
- lifting
- buckling
- end joint gaps
- side joint gaps
Some of these issues take months, or even a year or two, to become a problem. Others, like buckling of wood laminate or WPC vinyl, can show up within days of installation.
How do I know if I need subfloor repairs?
- cracks in a concrete slab;
- visible water marks;
- mold; or
- “humps and holes” (bumps and dips large enough to feel underfoot as you walk across the floor).
Beyond the more obvious visible problems, though, moisture issues and subfloor out-of-flat can cause damage to your floor even if they haven’t reached a level where they are noticeable to an untrained observer. Your builder or installer should perform a subfloor assessment once they have removed your existing flooring, and they should share the results of that assessment with you.
What is involved in a subfloor assessment?
All subfloors, whether concrete, wood, or a previous flooring product, need to be checked for three things:
- Compatibility with your new flooring product;
- Flatness; and
- Moisture levels.
Some flooring products have additional subfloor requirements that need to be checked, but compatibility, flatness, and moisture are universal concerns.
A proper subfloor assessment is quantitative, rather than qualitative. Moisture readings should be measured and recorded; flatness assessments should identify the locations of problem spots.
Often, homeowners are skeptical of subfloor assessments performed by the installer, due to the installer’s potential for a conflict of interest.
Luckily, there is no mystery involved in a subfloor assessment. What is measurable is also reproducible. The installer should be able to show you the areas of particular concern. You can ask to see the measurements, and even take measurements yourself.
Independent Third-Party Assessments
For your peace of mind, you can also hire a third-party subfloor assessment from an independent floor inspector. Floor inspector websites such as FCITS, CFIU, and Floor Detective (among others) have ‘Find an Inspector’ tools that will locate independent flooring professionals within a reasonable distance of your zip code.
Subfloor preparation is often not even on a homeowner’s radar when they start calculating the costs of a new floor. Some people avoid the added expense of subfloor remediation due to immediate budget constraints, a lack of trust in the recommendation, or simply unawareness of its importance.
At a minimum, however, your flooring project should include a thorough assessment of the subfloor conditions. Ultimately, the decision of whether or not to address any subfloor issues should be an informed one.
