Floor PIR board rocking

[pilgrim]

I am laying my insulation for under the floor and one of my PIR boards is bowed and I didnt realise until after I had cut it. This means that it rocks quite a lot if I stand on one side compared to the other it lifts up approx 15mm. This board was the last one I laid and it is cut to fit around the door frames so I cannot just flip it over to compensate for the bow.

The PIR is 120mm thick with 100mm EPS underneath it (which is flat!). I am going to be putting the egg crate matting underfloor heating system and 70mm of screed on top of these boards then laminate wood flooring boards on top of that.

Do you think this will cause me any problems or will it be ok to leave it? This is unfortunately in the highest foot traffic area, it is right in front of the front door and at the foot of the stairs / entrance to the living room. 

 

[PeterW]

Lift it and put a few cuts in the back of it and squirt a bit of foam into each cut then re-lay it with a couple of blocks on top to hold it down if you really want it flat but your screed will push it down tbh with the weight of that.
 

Don’t forget the slip membrane under the egg crates. 

[pilgrim]

38 minutes ago, PeterW said:

Lift it and put a few cuts in the back of it and squirt a bit of foam into each cut then re-lay it with a couple of blocks on top to hold it down if you really want it flat but your screed will push it down tbh with the weight of that.
 

Don’t forget the slip membrane under the egg crates. 

Ah I didnt think of cutting the back. I left some rubble on top of it over night so hopefully that will have helped. Yeah I have enough of my DPM left over to cover this top layer as well and I'll tape all the joints, hopefully it'll all be good and im just overthinking everything!!