Pitched roof, is 14x120mm enough to hold the insulation at cc120?

[Toobster]

As the headline suggests, I'm wondering if inner panel 14x120 is enough to hold back the insulation in our sloped roof. I haven't decided whether to blow in loose fill or install insulation boards. The insulation thickness will be 30 cm.

You don't want the roof to sag inward.

Best regards,

Tobias

 

[jerk]

What CC will it be between each board? It then depends on how hard they spray the loose fill. It has a great pressure if packed tightly, and then 14*120 might be too weak. CC 30 is the requirement if I remember correctly, and I would prefer 28*70 so it can also hold up things like a heavy lamp, for example.

 

[Toobster]

Hmm don't understand what you mean? The trusses are cc120 and the panel is 120 wide so it should be cc12 on the panel?.

 

[gadu^]

Jerk is thinking about gles as these are usually 28x70 which are placed with cc30.

Without knowing, but having fitted an attic with gles and gypsum, 14x120 feels a bit flimsy spontaneously.

 

[Toobster]

Mhmm.. I hadn't really planned to have sparsely at all. Just full-covering panels!

Previously, there was only full-covering raw boards on the inside of the rafters and then 1 tretex board. No spars to hold up the insulation there... is it needed?

 

[gadu^]

Not really necessary, but the question is whether your panel can withstand the insulation without starting to sag...
I assume the panel is tongue-and-groove?

 

[Toobster]

yes, it is tongue-and-groove. But whether it can handle it is what I was wondering about.

http://www.moelven.com/se/Produkter...or/Golv-och-panel/?prod=5962&prodcat=1895_244

 

[BigGitt]

Spray a little harder, it won't hold. If you place discs with thread or string as support, it will hold. Type 2x145mm.

 

[Toobster]

Mhmm.. how do you tighten these wires? Steel wire between the rafters?

 

[BigGitt]

One can take regular fishing line and stretch it against the first rafter with regular clips along the entire house. And turn. So that there is, for example, 20cm between each line. You insert the is6lering. Build on the next 145mm stud. Stretch the line. Is6lering. Plastic. Panel...

 

[Toobster]

aa ok thanks for the info.. unfortunately, I have full trusses.. or will have.. that are barely 40cm "deep", but maybe one can stretch wire zigzag inside between the trusses.

 

[pbengtsson]

If you install sparsely, you can place the panel in a different direction, towards the ridge. It's quite tricky to fit the insulation if you have to be careful and keep an eye on lines and age-resistant plastic.

 

[BigGitt]

If you thin, it's just as good to spray in. Ready in 3 hours.

 

[Toobster]

ok.. so the order is:

1. set gles
2. pull electrical
3. Plastic
4. set panel
5. blow in insulation

or?

 

[pbengtsson]

1) plastic/windproof fabric (check with the insulation manufacturer)
2) sparse
3) Spray insulation
4) Install electricity (might work before spraying too)
5) panel

How do you handle the air gap against the outer roof, I assume it's already there.
If you are going to spray, it's important that it is sealed at the eaves as well.