cold bridging

paulmallon

I am makeing my own lintels for a sunroom.
J ust wondering is it ok to make a solid steel plate say, 300mm wide to support both inner and outer leaf or does this give rise to cold bridging?
Would building control even approve this type of lintel?
would it be best to have 2 seperate lintels?
ive been looking at those keystone ones but they are very sore on my wallet!!!

Mellor

If you were to use a flat steel plate it would have to be quite thick. This results in a cold bridge.
To increase the strength of the lintel it is normally bent in the middle (various different shapes). This bend makes the lintel stronger, therfore it can be thinner. I'm trying to think of an everyday example of this, think of a metal venetian. The single metal pieces are quite rigid in one direction and not in the other. Far more rigid than if the piece were flat.
A bent lintel is thinner and longer so less heat gets through.

Another option is of course two lintels, one on each leaf. An "L" angle of the right strength cound do this.


Price "catnic" lintels and see how they fair.

ardara1

The new\accreddited details for Eng & Wales will insist on 2 separate lintel - perhaps better going this direction now? - if a single plate is used at present it must be perforated (???)