We have a maple hardwood floor that was installed & finished on-site in September. Since we moved in (November 1), we have maintained the level of humidity at 35% to 40%. Unfortunately, large gaps and splits in the boards appeared after less than 2 months.
Why did this happen?
I don’t believe a customer should accept a floor like this. How do you recommend dealing with the contractor and convince him that the floor needs to be replaced?

Thank you for your advise!

Gaps in between the boards usually are caused by the flooring shrinking width wise. This could be caused by a couple of things.

* The flooring was delivered and installed without proper acclimation. The moisture content was too high. Without the contractor measuring the MC, it's hard to know for sure.
* The home had a higher humidity level in Sept, when the floor was installed. If your relative interior humidity was around 50% or more ( common for homes in the late summer ), and now it is 35% ( which is too low ), this can cause the boards to shrink as well.

Since we are coming out of the heating season in many areas, it is normal for floors to shrink slightly during the heating season, unless to have humidity controls in your home and keep it at the same RH year round ( 45 to 50 % is considered ideal ). Furthermore, maple is pretty unstable, and being light in color, gaps show much more readily. I know this from 30 yrs. of experience. So, either wait till the humidity returns to normal ( Next Sept ) or use a humidifier to get the interior humidity levels up to normal.

This may not solve the entire problem. If it does not, you may need an independent inspection to assess if there are installation discrepancies. I would highly doubt the contractor would readily agree to a complete replacement. If the boards do not return to normal after a year and normal humidity levels, he may agree to fill and re-coat the floors, which is an acceptable remedy in many cases.

It is wood, doing what wood, does.

It has lost moisture since the day it was installed.

Wood being hygroscopic, swells with added moisture and shrinks with a loss of moisture. Humidity is the moisture vapors. Drop the humidity and the floor shrinks, add humidity and the floor swells.

Every different species of wood, shrinks and swells different amounts, given a percentage of added moisture. Maple just happens to be a species that shrinks a lot, and swells a lot, with little moisture change.