kingspan adhesive

[elmsoft]

Hi
I am using Thermaroof 127 to insulate my extension ( warm ) roof. I will be nailing the vapour barrier and then want to use adhesive to fix 120mm TR27 to that, followed by 50mm TR27 to that, and then 9.5mm OSB to take a fibreglass top surface.
I have looked at the on-line installation video on the Kingspan site and it refers to “suitable adhesive” . I am not sure what exactly that means and want to ensure that the adhesive I use is indeed suitable. Can anyone suggest either a more detailed specification or exemplar trade product?

Thanks

 

[Doggit]

Well I'll first admit that I'm not an expert at this, but I think you're going around this the wrong way. The thermaroof already has a vapour barrier in to, and the vapour barrier goes on the underside of the insulation, not the insulation getting glued the the barrier. A more standard method, would be 18mm osb on top of the rafters, then put 120mm of kingspan between the joists, then fix your VCL to the underside of the joists, and then fix the plasterboard to the joists. 170mm of thermaroof is a bit excessive, but someone may correct me.

 

[elmsoft]

Thanks Doggit.
I'm sure you are right but I think you are describing a "cold roof". The method I'm describing is I think a "warm roof" ( I might have it the wrong way round).
Anyway, it's the method that the plans specify and the 170mm is in the drawings too. So right or wrong the BCO expects to see it.

 

[Doggit]

Actually no, the BCO will often take a reasonable view, and advise you what he wants to make the build comply with regs. He's not bothered if you follow the plans or not. In the case of a loft, a warm room is one where the insulation is under the rafters so that the room up there is warm, and a cold loft would have the insulation in between the ceiling joists. I will be admit that I've never understood the transition to a flat roof for those terms though. But if you were to have downlighters in the ceiling, then you'd have the insulation above that, so that'd be a warm roof, and if the insulation was just above the plasterboard, then I think that that gets classed as a cold roof, but with 170mm of insulation, I think the whole void is being filled, so not sure of the true designation.

 

[noseall]

A warm roof is one where the insulation sits wholly above the roof timbers. The idea being that the roof timbers are at the same temperature as the room below (warm), thus removing any cold spots and dew points. As long as the insulation is thick enough then there is no need for anymore insulation between or under and no need to ventilate.

Anything else is cold or hybrid roof and will require robust methods of fitting or ventilating in order to deal with problems associated with condensation.

Currently 120mm of Celotex type insulation above the joists/rafters is sufficient as a warm roof. We use 180mm spax fixings for this type of roof. As long as you have adequate joint support noggins in place and your joist spacings are no more than 400mm then you can fix say 126mm Kingspan insulated deck, direct to the furrings/joists and lay your roof material on top.

 

[freddiemercurystwin]

Actually no, the BCO will often take a reasonable view, and advise you what he wants to make the build comply with regs. He's not bothered if you follow the plans or not. In the case of a loft, a warm room is one where the insulation is under the rafters so that the room up there is warm, and a cold loft would have the insulation in between the ceiling joists. I will be admit that I've never understood the transition to a flat roof for those terms though. But if you were to have downlighters in the ceiling, then you'd have the insulation above that, so that'd be a warm roof, and if the insulation was just above the plasterboard, then I think that that gets classed as a cold roof, but with 170mm of insulation, I think the whole void is being filled, so not sure of the true designation.

Doggit, respectfully everything you've said here is incorrect in some way, really if you don't know please don't post.

 

[noseall]

Here is a flatty being prepared for insulated deck complete with side support trays and joint noggs. The second image shows the furrings too..

Flatty1

• noseall
• 15 Feb 2018

Flatty2

• noseall
• 15 Feb 2018

 

[Doggit]

Doggit, respectfully everything you've said here is incorrect in some way, really if you don't know please don't post

Well it may be, but I don't know that I'm wrong till someones kind enough to correct me, and I did say that I wasn't completely sure. I am always glad when someone teaches me more than I knew yesterday, but thanks for the polite way you did it; not everyone on here has your manners Freddie

 

[John D v2.0]

Cold loft and cold roof are different. Cold loft is where the void is outside the insulation, cold roof is where the timbers are partly on the cold side of the insulation.
Loft is a choic for convenience of t occupier, roof is a design choice for the building fabric