Cold vs Warm roof. Should I care?

[^woody^]

most important word, 'if'

Yeah, like if I dont put self raising flour in the cake mix, if I don't put the remote where I can find it, if I don't put clean pants on in the morning.

Not just in roof construction, but in anything, if you dont do something right then things will go wrong or will more likely to go wrong.

 

[^woody^]

I'm assuming you mean 90mm circles? I need to measure but the squares they have done look almost the width of the joists. So it's 300mm squares. I cannot see how they can effectively fill those in, I bet they weren't planning to. Is this just lazy or standard?

You need to ask them. Those voids could be left out so that the lights can be wired in, and then the insualtion replaced. Its common.

But what you need to be sure of, is that the builders are following the approved plans, fitting the insulation in accordance with the insulation manufacturers guidelines, and fitting the lights in accordance with the light manufacturer's guidelines, and following any other Standard that may have been specified in your contract.

Some lights are low heat, some lights give off more heat, some require more space around them than others, some require a smoke/flame hood some will have this function built in to the housing.

I doubt very much that your plan drawer has specified Enlites. So it will come down to who decided to use them and if they are compatible witht the specified roof design. This issue (ie related to design and compatibility) is completely different to the quality of the workmanship.

 

[Notch7]

I'm assuming you mean 90mm circles? I need to measure but the squares they have done look almost the width of the joists. So it's 300mm squares. I cannot see how they can effectively fill those in, I bet they weren't planning to. Is this just lazy or standard?

Its 90mm deep, 70mm dia.

What the builders have done is put some insulation in and left squares missing, to be filled in later.
Its allowed the downlight cable loops to be put roughly in the right place.

Ive always done warm roofs with downlights to avoid the awkwardness of cutting pockets out of the insulation

 

[Mmark]

You need to ask them. Those voids could be left out so that the lights can be wired in, and then the insualtion replaced. Its common.

OK that's good to know, I'll bring this up later today. Just trying to arm myself with knowledge, before I talk to them. So appreciate the advice.

Someone else said to get downlight hats, not for the fire rating as lights are fire rated, but to help with the cold. Good idea? Anyone recommend one that is particularly good for its thermal properties?

I doubt very much that your plan drawer has specified Enlites. So it will come down to who decided to use them and if they are compatible witht the specified roof design. This issue (ie related to design and compatibility) is completely different to the quality of the workmanship.

The architect diagrams were warm roof, so this is all new territory The Enlite Pro E6 where just what the electrician said he prefers to fit. I actually asked for Ansell Orbios (have them in the kitchen), but the Pro E6 were similar spec (same beam width, 6w instead of 8w with only 50 less lm), so I said OK.

I asked builder (sales person, not site manager) today about that. He said "we asked you at the beginning of the project, if you wanted more or less head head. You said more head height, and we said that means cold roof". This might be true, back then I was clueless on cold v warm roof. Probably I'd still prefer the head height, as long as the cold roof is installed correctly.

 

[Leofric]

Might have missed something but have you been back to the architect to check that these revised details comply with building regulations ?

 

[johnny2007]

we asked you at the beginning of the project, if you wanted more or less head head. You said more head height, and we said that means cold roof"

That's not true, cold roof doesn't hive more head height, if anything it reduces it.

 

[Notch7]

we asked you at the beginning of the project, if you wanted more or less head head. You said more head height, and we said that means cold roof

Bulls hit.

As Johnny said.....not true.

Anyway, you need to remind them they were contracted to build to architects drawings........you pay for an expert so you dont need to decide things out of your area of expertise.

Warm to cold roof is not a minor change, it shoukd have been referred back to architect.

 

[Leofric]

This 'more or less head height' thing is misleading. If you design the roof from the internal head height you require it doesn't matter whether it is a cold or a warm roof; but if the roof has to be designed from a fixed external ridge level, then having the insulation over the rafters as a warm roof would reduce the internal headroom.