Engineered Oak flooring splitting

[fatmcgav]

Hey there

We purchased and installed engineered oak flooring as part of our living room renovation a bit over 12 months ago.
The flooring was installed over a screeded wet UFH system using Bona R848 Flexible wood adhesive. The screed was given plenty of time to dry before we installed the flooring.

However recently we've started noticing that some of the boards appear to be splitting. Some are just at the ends, but a couple appear to run pretty much the whole length of the board.

Attached are a few photos of the worst boards.

Has anyone seen this before? Any suggestions on what could be causing this? Is this a product defect, installation error?

I've also emailed the company I purchased the flooring from to see what they think. The flooring is advertised as having a 25 year guarantee, so for it to be splitting after a little over 12 months feels poor.

 

[crazydaze]

The issue with the floor will be down to humidity and/or heat. Splitting is normally attributed to heat/drying out rather than excessive moisture. It would be worth double checking the specs and use of the UFH system compared to the recommended max temp specs of the floor, I suspect that the manufacturer of the flooring will point a finger of blame at the UFH being used at to high a heat for the product.

 

[fatmcgav]

So I've just pulled the cabinet apart to get to the ufh manifold, and it looks like inlet side was running at about 50c, with a return temp of around 40c... So possibly was a bit high...

I've tweaked the inlet temp and flow rate and just letting it settle for a bit...

 

[fatmcgav]

So the company arranged for an "independent" inspector to come round and inspect the flooring.
I've just received a copy of the report, and this is the summary:

Some planks have splits and cracks.
The flooring is level and glued to a screened subfloor with the correct
expansion gaps. There are no sign of damp and the humidity levels on the day
of the inspection were low. These readings on the day of our inspection have
no bearing on what they may have been when the problem first arose.
The flooring is suitable for under floor heating.
The consumer noticed the cracks in the planks about 12 months after fitting.
Wood being a natural product is affected by moisture and humidity. The wood
expands and contracts e.g. during the winter when the heating is on, the wood
loses moisture and will contract.
There was one area, please see photos, where there was a slight rise and gap
in one of the planks.
All this has been caused by changes in humidity, which is seasonal. This
indicates that there has been fluctuating temperatures and humidity.
Although the consumer is disappointed in the floorings appearance, this is not
a product fault but caused by localised conditions.

Surely "fluctuating temperatures and humidity" is normal for every house that this flooring gets installed into? Is it not unreasonable to expect the flooring to be able to withstand such fluctuations?

 

[foxhole]

Found this on several sites, seems yours is way too hot .
Your underfloor heating must be designed in such a way where you do not get hotspots beneath your floor. The underside of your flooring must not reach temperatures above 27 degrees celsius. If any areas of your floor exceed these limitations it may cause damage to your floor.

 

[crazydaze]

Foxhole is correct, the floor has seemingly been laid way outside it's temperature operating parameters by the looks of it.