Flat Roof Insulation - Quote

[canalsiderenovation]

We are just reviewing our builders quote for our flat roof area. Does this look sufficient insulation? 

 

200mm joists

18mm plywood decking

120mm Kingspan Thermaroof TR27

Hertalan single ply membrane

[wozza]

Is the 120mm Kingspan being fitted between the joists or above?

 

 

Edited April 6, 2020 by wozza

[canalsiderenovation]

9 minutes ago, wozza said:

Is the 120mm Kingspan being fitted between the joists or above?

 

 

Errr no idea. Having call with builder so need to ask. Does it make a difference??

[Moonshine]

23 minutes ago, canalsiderenovation said:

Errr no idea. Having call with builder so need to ask. Does it make a difference??

 

yes, above the roof (warm roof) won't that the bridging of the joists. However i would say from how it is described that its above the joists.

 

Also how are they doing to achieve the 1:80 fall?

[canalsiderenovation]

13 minutes ago, Moonshine said:

 

yes, above the roof (warm roof) won't that the bridging of the joists. However i would say from how it is described that its above the joists.

 

Also how are they doing to achieve the 1:80 fall?

 

I've written it as it is in the quote so likely above. No idea re the fall. That's one to ask....

[Temp]

Recommended reading..

https://www.labc.co.uk/news/how-avoid-defects-claims-flat-roofs

 

https://ebcsltd.co.uk/wordpress/wp-content/uploads/2016/09/13flatroofs.pdf

 

Make sure you understand the difference between a so called warm and cold roof construction. Traditional cold roof types must be correctly ventilated to minimise risk of condensation forming in the roof and rotting joists. If you have the height available a warm type is recommended these days.

 

Edited April 6, 2020 by Temp

[canalsiderenovation]

Thanks @Temp those links were really helpful and put me in a better situation to ask questions tomorrow.