Hi, It's a long while since I laid herringbone woodblock. Actually it was about 40 years ago when it was reclaimed and you dipped the block into a bitumen bucket!! Anyway, my son has just had an engineered herringbone floor laid on a screed concrete base. (House 7 years old - B&B floor) Apparently they trowelled the floor with adhesive and then used a tubed adhesive on the back of the blocks. But after it was laid, I noticed a reasonably large area (1 - 1.5 meter's) just as you walk into the room which has either become unbonded or never stuck. (I suspect adhesive skimmed over or dust). It was only laid a week ago. Sounds hollow when tapped. The fitter is saying that its all OK and it could be the subbase not stuck or an undulation and isn't a problem. As I have been out of this game for a while (Wall & Floor tiler) does is this acceptable?
Hi, thanks for the reply. Pretty sure Subfloor is power floated over Block and beam. The house is only 7 years old. So it would be extremely unusual to have any areas that are blown. Installer said it’s definitely stuck to the floor. Said if the floor was out of level there maybe voids underneath making it echo….. but even so, if that was the case (which in my mind would be bad practice. Surely you check the floor before you start with a straight edge?) it would be bonded in the blobbed areas? In tiling you wouldn’t expect any blown areas?
So did he grind the power floated floor , do a moisture test then if needed apply a moisture suppressant then a 3-5mm smoothing compound. Most power floated floors will have a wax finish which you can’t glue to
He did say that he likes to put a membrane down normally, but as it was quite a new substrate I did advise my son to leave it. (As you know damp is very unusual on a suspended Block and beam floor due to the construction method used) He didn’t latex any of the floor. Stuck straight on. No grinding at all. I just can’t see how hollow areas are acceptable in a floor layers book? It’s a bit like a dodgy tiler “Blobbing” the back of tiles on an uneven floor? But I’m not a wood flooring expert. Hence why I found this forum
You do get hollow spots with wood flooring. The adhesive is a lot thinner than tile adhesive. You can’t really build up like you can with tile adhesive. If the floor is flexing or creaking it’s a problem. A large hollow spot can be injected or removed and repaired.
Thank you for your reply. Yes I can understand some areas…. But over a square meter patch is a bit annoying. I did think of some type of injecting (Tilers do this as a repair for hollow areas) but didn’t know the system used and whether it would create any problem as it wood. However the engineered flooring must be 20mm thick. Is there a particular product you recommend?
