2nd layer of osb underfloor

[Eldad]

The builders if my garden studio have installed osb underlay in top of joists that are spaced around a 50cmx100cm insulation.

It took them a long time to build the roof and a lot of rain has fallen on the floor (it was covered but this wasn't enough). 

Now, the underfloor is squeaking and the side of each board has swelled a bit. 

They have agreed to add an additional layer of boards before we lay down ufh and lvt. 

They want to use 18mm osb boards but I read that plywood would be a better option, even 12mm.

 

Should I insist on the plywood or will osb be enough? 

[jfb]

Did they glue the osb down with expanding PU glue?

squeaking could be because they didn’t use any and so might still squeak regardless what you put on top

[Eldad]

I don't think they used glue. Looking at old photos, it looks like they only used screws. 

[Nickfromwales]

9 minutes ago, Eldad said:

I don't think they used glue. Looking at old photos, it looks like they only used screws. 

That will squeak forever more.

 

Take the OSB off, bite the bullet, or regret it for….ever more.

 

Adding layers = 💰🔥

[Nickfromwales]

Oh, and use glue!!!!!!!!

[marshian]

12 hours ago, Nickfromwales said:

Oh, and use glue!!!!!!!!

 

yep for a floor with lots of foot traffic glue the joints...

 

For a loft with virtually no traffic just screw (never know when you might need to lift a board for access)