Closing the cavity on a gable wall!

[Salmon]

Hi All,

Just a quick question for those in the know! Do you need to close the cavity on a gabled wall. My blocklayer is currently building the gable walls of my house and I am building up a cavity which is insulated with xtratherm rigid board insulation. Some people I have talked to have told me that I should close off the top of the cavity with concrete and others have said that when the roof goes on this will be sufficient for this job.

Any advice?

Salmon

 

[kiwijbob]

you should close the cavity ALWAYS ! see page 169 of the 4th
edition of the homebond book. You need this closed for thermal
insulation properties

 

[Carpenter]

The cavity must be closed, to prevent thermal looping and maximise the insulant efficiency of the air retained in the cavity. The traditional method to do this was to pack the cavity, shutter and pour a concrete "closer". This method was labour intensive and now most authorities would be happy to see the cavity closed with slates or tiles, bedded in mortar, with overlaps. Cavity Trays do a great product called the "Type J" cavity closer and support which gives you the "Rolls Royce" solution at a cost!

 

[manukev]

your blocklayer will probably cut strips of insulation and close the cavity with these,like you would see done around window and door opes