joining new wall to existing cavity wall

[sudbrooke]

I recently had an extension built onto the existing house (which has cavity walls). The builder simply butted up the new wall to the old, using ties that were screwed to the old wall and set into the mortor joionts of the new wall.

Now I am planning another extension and I got a different builder over to discuss. He sais you should always cut into the olf wall, through to the cavity, and make th ecavity of teh old and new wall continuous , other you get a cold point and damo can get through.

I see this maks sense, but do buiding regs. require it, and why did the previous builder not do it, or the building inspector require it?

 

[PrenticeBoyofDerry]

did they intall a strip of damp course, when they fit the wall starter?

 

[jeds]

Your new builder is right. The old builder was either too lazy to do the job properly or couldn't be bothered because he just wanted to get the job done as quickly as possible and didn't care what the result was like as long as it looked good enough for you to pay him or he didn't know what he was doing. The building inspector probably didn't see it, or if he did he couldn't be assed to do anything about it.

Could be any of these. Not very satisfactory I know, but there you are.