I’ve seen a few problems up here in Canada with cupping of newly installed prefinished hardwood floors. Each individual board is cupped and there is no overall heaving of the hardwood flooring. There does not appear to be jamming at the edges (which makes sense ’cause the floor is not heaved) so I’m pretty sure that the problem is not just a matter of poor acclimatization to the house interior humidity and resulting expansion. It seems to me that this is just an issue of excess humidity in the house resulting in each board swelling more at the underside (where it is unfinished) as compared to the top side, which is finished. This is much the same as we see on outdoor decks with only the top finished. Unfortunately, I don’t usually get called right away to look at these problems, so the inside RH levels are different from what they would have been shorthly after installation, but high humidity seems to be the likely culprit.
I’m just wondering if anyone has noticed that prefinished floors have more board cupping problems than site finished floors and whether or not some of you have taken to advising clients in more humid houses to stay away from prefinished floors altogether. It would seem that, regardless of how long you let the boards acclimatize before installation, if its too humid in the house the boards will cup regardless.
Thanks. This is first time on the board, so I’m looking forward to joining the fray (and be gentle on me!).
Replies
Don't know what brand or what storage conditions or how the supplier stores his stock or what underlayment and prep, or a zillion other things. I don't especially care for the appearance of prefinished, but my experience has been that it is very consistent and durable and less prone to cupping than site-finished products. Contact the manufacturer and ask them for comments.
Pre-finished will cup more than bare boards because the finish will slow moisture absorption into the finished face.
Pre-finished (and preferably unfinished flooring) shouldn't be installed until the house is tight and dry and at the moisture/heat levels it will have during occupation.
IanDG
Have you ever investigated the moisture content of the subfloor? And what is the slip sheet that's installed under the hardwood? Welcome to the board.
Remodeling Contractor just outside the Glass City.
Quittin' Time
Unfortunately, I get the call to the site months later, thus the moisture content at the original time of installation is unknown. At the time of my site visit the moisture content of the subfloor, the floor itself and other wood items is typically less than 9 %.