Floor structure for small outbuilding

[MP1]

Good afternoon,

 

I am building a small outbuilding (30sqm - office and gym) on a raft foundation. The raft and walls are already in place and I trying to figure out the bast floor structure. Currently I am looking at:

 

- DPM atop of the raft foundation concrete

- 130mm PIR insulation atop of DBP

- 22 OSD atop the insulation

- floorboards atop the OSD

 

What do you think about this structure?

How would you recommend bonding all the layers together?

 

Any suggestions would be much appreciated.

 

 

[PeterW]

OSB is a floating floor layer there so you want to glue the boards together and use T&g OSB. Sheer weight will hold it down, if you’re really worried then a couple of thin beads of expanding foam will glue it to the PIR. I’d consider laminate rather than floor boards but if you use boards then just use hidden nails to secure them to the OSB. 

[MP1]

Thank you @PeterW It makes sense. I think I will opt for laminate and some rubber floor in the gym area. 

 

This may be a basic question but I have not done it before:

Does the DPM have to be glued to the concrete with anything (e.g, silicone?) and then the PIR to the DPM?

[MP1]

Ok, I think I know how it needs to be done.

 

For everyone who may be looking for the same answers:

 

 How to construct a floating floor | Insulation | Kingspan | Great Britain