laying floor insulation

[plugy]

Trying to lay some pir floor insulation over a garage floor then caberdeck. Is there an easy way to do this?
The insulation seems to be bent, so laid sand down to compensate but proving a lot harder than we thought.
the panels still seem to move when stood on (flexing). Will the weight of the caberdeck firm them up?
Any advice would be appreciated. Doesn't seem to matter what we do cant get them to be totally solid.

 

[endecotp]

Yes they will straighten out under the weight of the flooring, to some extent.
There was a similar thread not long ago in which Woody suggested making some cuts in the boards to help them straighten out. I’ll see if I can find it.

Edit:
https://www.diynot.com/diy/threads/...much-how-to-push-it-down.538623/#post-4552894

 

[plugy]

Thanks for the help, well had a go at putting them in today. What a b*******d to do. Some of the PIR boards were 2 inchs out, like a banana. They have been in and out that many times trying to get them right. Been impossible. Done our best, taped the joints and filled the gaps. Started to put the caberdeck over the top but some gaps underneath, so the floor is flexing. I am assuming you can fire some expanding foam underneath and let cure to take up most of the play? Will this work?

 

[endecotp]

Two inches is a lot. How did they get like that?
I suspect they will bend back given time and some weight. Are you in a hurry?

 

[plugy]

Already in, probably the last few bits of crap for the builder's merchants. Will post on the DIY disasters next week.