Tongue and groove separated on the edges

Q: I had engineered oak floors installed in October. They are tongue and groove, and were laid as a floating floor in my condo. Now, some of the boards have separated on the edges. The separation is around 3mm or so. What could be the cause?

Thank you for your time.

A: I wouldn’t have expected this with an engineered floor. They are constructed similarly to plywood so the boards are very stable. I can’t imagine that the top, hardwood layer would be able to shrink independent of the other layers. And I assume this is a click type of joint. Generally this type of joint required inserting the next board on an angle and then pushing down to click them together. It shouldn’t just pull apart. Changes in moisture content are generally the cause of wood shrinking or expanding. I think I would contact both the installer and the manufacturer. If this was a solid hardwood floor, nailed down these gaps would be very minor and normal. I’m not so sure I can say the same for an engineered floor.

Follow-up Q: Thanks for your answer.

This is actually a tongue and groove system, and the boards are glued to each other on the edges. This is not click. This floor was installed as a floating floor. Does this change your opinion? I don’t know if this was an effect of moisture, but the moisture is not affecting any other area. Maybe the glue gave up?

A: Okay, interesting. I said ‘click’ because in the early days of laminate flooring, before click joints each panel was glued together, squirting the manufacturers recommended adhesive into the groove. Then they invented the various joints that snap together and the glue joint went away. But those floors, as laminates still are, are rather thin. Some engineered floors are not thin but rather 1/2″ to 5/8″ thick. I would be doing some research before relying on a glue joint install with a floor that thick. Here is what I would do. Go to the web site of the manufacturer, unless you have the directions that generally come with each box of flooring. Find out if they recommend this type of installation for that product. It sounds like the floor may have shrunk a tiny bit and it has pulled away. If this were severe shrinkage It could potentially start breaking either the tongue or bottom edge of the groove side. That hasn’t happened which is good. Find out from the manufacturer if they recommend this type of installation.

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