Roof insulation

[Francie 6,362]

3 minutes ago, NEWKID said:

If you were putting insulation board under your roof tiles, so up in the rafters you would need to leave a space between the roof and insulation for air flow...

But you will be insulating above you ceiling, so the air flow won't be affected

I'm just doing in-between joists of the ceiling keV,thanks for your help mate.

[slip lead 862]

The old fiberglass stuff isn't as worn but isn't a fire hazard,  celotex, kingspan and other foam insulation is.

Edited November 29, 2020 by slip lead

[NEWKID 26,191]

23 minutes ago, slip lead said:

The old fiberglass stuff isn't as worn but isn't a fire hazard,  celotex, kingspan and other foam insulation is.

Not anymore mate, insulation board has had to change massively since Grenfall... minimum 1 hour fire resistant i think...

[Francie 6,362]

Thanks for the help men

[si brown 8,486]

I used this stuff over the top of glass insulation in my loft, just staple it to top of joists and board over!

ive built new houses and used it in cavity walls on special wall ties too. 
https://www.ebay.co.uk/itm/Per-Metre-1-2m-Wide-Double-Foil-Insulation-Aluminium-Bubble-Shed-Loft-Attic-Van-/293189039259?_trksid=p2349624.m46890.l49292

[PLEDGEY 493]

Kingspan/Celotex has twice the insulation of rockwool. There's another insulation product that's called Tri iso 10. It's supposed to be as good as kingspan but only about 20mm thick. Don't get that, it's mad expensive and failed building control tests.

[mC HULL 10,440]

On 29/11/2020 at 19:07, NEWKID said:

Insulation between the joists, as much as you can (probably 150mm or 200mm depending on joist depth), ply on top and then you can store easily up there...thats what I would do anyway..

I’d be careful what weight you put up there joists really want doubling before you think about boarding loft and storing up there or all your up stair ceilings will need replastering at best

[dublin dezzy 1,023]

Spray foam best stuff ive used in an attic covers every part and not too expensive

[Francie 6,362]

23 hours ago, si brown said:

I used this stuff over the top of glass insulation in my loft, just staple it to top of joists and board over!

ive built new houses and used it in cavity walls on special wall ties too. 
https://www.ebay.co.uk/itm/Per-Metre-1-2m-Wide-Double-Foil-Insulation-Aluminium-Bubble-Shed-Loft-Attic-Van-/293189039259?_trksid=p2349624.m46890.l49292

Do you mean staple it on top of joists si,or in between like the wool?

Just one layer?

[si brown 8,486]

6 minutes ago, Francie said:

Do you mean staple it on top of joists si,or in between like the wool?

Just one layer?

I stapled it over the joists in full lengths and taped the joints with alloy tape.

I didn’t use the stuff off eBay as it was what we use on site but it’s the same stuff. 
we used it on loads of houses for the nhbc/ Barrats 

[mC HULL 10,440]

1 hour ago, dublin dezzy said:

Spray foam best stuff ive used in an attic covers every part and not too expensive

Remember roofs breath that sprayed on to roof tiles is a bad idea plus if you get a leak you won’t no until wood is rotten everywhere atb

[Francie 6,362]

3 hours ago, si brown said:

I stapled it over the joists in full lengths and taped the joints with alloy tape.

I didn’t use the stuff off eBay as it was what we use on site but it’s the same stuff. 
we used it on loads of houses for the nhbc/ Barrats 

Thank you si

[mC HULL 10,440]

On 29/11/2020 at 19:10, Francie said:

What do you mean bramble?

 

On 29/11/2020 at 19:10, Francie said:

What do you mean bramble?

He properly mean your roof breaths mate or it would get condensation even if you put to much insulation on the eaves were your base plate is for instance will cause condensation 

if you was doing it properly we’re roof tiles are depending on type of roof you would put 2 vent tiles bottom 2 vent tiles top of roof each side the use kingspan in between but leave a gap between felt and insulation and then plaster board then from eaves to the ridge is breathing 

the floor is another ball game all together depending on we’re base plates are you may need steel joist putting from one base plate to the other spanning house 

then you have to double your joist bolting threw and notching at each base plate spanning house 

then you can board and start thinking about chopping out 

you get it wrong it can lead to a whole heap a shit down the line atb

[mC HULL 10,440]

[mC HULL 10,440]

This vented at eaves and ridge mate