Insulation - Awkward Spaces - Expanding Foam And Under Floor Insulation

[Owain]

Hi,

Have used lots of sound deadening and sticky back foam insulation; but still got those awkward struts across roof.

Do i ignore and just foil over them or carefully fill with expanding foam?

Also i have put deadening under whole floor, but no insulation. Not sure if to use sheet of celotex then laminate or just put my sheet of 12mm ply back down before using lino?

Any advice?

 

[Owain]

 

[Fish]

No not foam them.!

 

[Teesix]

Evil stuff it is.

 

[Owain]

Yep have resisted so far. But short of another layer of dodo over them, which means not so easy to replace roof and a lot of headroom....

 

[t0mb0]

Seems a high risk strategy! If you do try it though, make sure you use a proper foam gun, the stuff straight from the can is impossible to control.

 

[oldiebut goodie]

That expanding foam is open cell usually - it can absorb water ( the last thing you want in there).
I knew someone who had the bright idea of using it in a dinghy, it took him ages to dig it all out after it absorbed water!

 

[Owain]

So thats a good reason NOT to use expanding foam. But so far no sugestions for alternatives.

 

[DXX]

If you insulate the floor won’t there be an issue with the side step not fitting? I know the California step is a deeper option but probably not enough for a sheet of Celotex.

 

[Skinnysye]

Depending on the thickness put your sticky back foam down, then plywood and fit a deeper step, I wouldn't use celotex but somebody may come along and prove me wrong.
I used this type of insulation under the plywood floor.
Van Insulation Lining - Self-adhesive foam with foil inner surface
And bought one of these steps to your required depth
Caravelle Side Step

 

[Owain]

I have 4.5m of dodo extreme, 17mm foil backed left after doing sides/roof . So i may use that...

But no solution for those roof spares.