Green Building Forum - flat roof help Wed, 01 Jul 2026 00:53:43 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 flat roof help https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237449#Comment_237449 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237449#Comment_237449 Tue, 08 Mar 2016 22:48:51 +0000 marsaday
I am doing a lot of work on the house and will be rewiring. So the plaster board ceiling is coming down in the kitchen, where the flat roof is.

Currently there is some cotton wool type insulation. I would like to fit kingpan in there instead, but understand it is not quite as straightforward as that. I will need to leave a 50mm gap and provide ventilation.

At the moment there is no ventilation and i am not sure if i can get any in there. So could i just fit the kingspan and fit a vapour barrier on the underside of the joists before i fit the plaster board ?

I also need to fit firings to give the roof a proper fall.

A warm roof sounds ok to do, but my flat roof area is 23sq/m, but only about 13 sq/m is actually a room (kitchen). The rest is a garage and so i don't need to insulate the whole area and i would need to do that is i made a warm roof.]]> flat roof help https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237451#Comment_237451 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237451#Comment_237451 Tue, 08 Mar 2016 23:06:07 +0000 tony flat roof help https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237452#Comment_237452 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237452#Comment_237452 Tue, 08 Mar 2016 23:10:43 +0000 ringi flat roof help https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237509#Comment_237509 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237509#Comment_237509 Wed, 09 Mar 2016 18:54:50 +0000 marsaday
It is going to make things so much harder for myself if i have to insulate on top of the deck and then make a new deck. I also need to put in some firings to create a fall. I am a bit lost with it.]]> flat roof help https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237510#Comment_237510 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237510#Comment_237510 Wed, 09 Mar 2016 19:54:15 +0000 djh Posted By: marsadayIt is going to make things so much harder for myself if i have to insulate on top of the deck and then make a new deck. I also need to put in some firings to create a fall. I am a bit lost with it.
You can buy insulation sheets that already have a fall built-in, which might make things simpler for you, but probably more expensive; I don't know their price.]]> flat roof help https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237512#Comment_237512 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237512#Comment_237512 Wed, 09 Mar 2016 20:46:50 +0000 tony
You are committed to taking the deck off I reckon as difficult to add firings without.]]> flat roof help https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237517#Comment_237517 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237517#Comment_237517 Wed, 09 Mar 2016 22:11:10 +0000 marsaday
http://www.diydoctor.org.uk/project_images/building_a_flat_roof/warm-flat-roof.jpg

Warm Flat Roof: By fully packing a warm flat roof with insulation there can be no air to condense. However this type of warm roof relies on there being absolutely no voids whatever otherwise interstitial condensation will occur and this can go unnoticed for many years.]]> flat roof help https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237518#Comment_237518 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237518#Comment_237518 Wed, 09 Mar 2016 23:12:13 +0000 Nick Parsons
A Warm Roof (note the capitals) has the structure below, and the insulation on top.]]> flat roof help https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237519#Comment_237519 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237519#Comment_237519 Wed, 09 Mar 2016 23:14:27 +0000 gyrogear
(Otherwise, how will the latter breathe ?)


Posted By: Nick ParsonsA Warm Roof (note the capitals) has the structure below, and the insulation on top.


+1 for that ...

gg]]> flat roof help https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237529#Comment_237529 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14105&Focus=237529#Comment_237529 Thu, 10 Mar 2016 09:56:18 +0000 djh Posted By: tonyLikely they won't have enough fall.
available ex–stock in falls of 1:30, 1:40, 1:60 and 1:80.

They all have BBA of course.]]>