Garage Conversion, help needed interprating building control

[higgster]

hi guys,

I am converting my semi integral garage.

Had the building control guy round yesterday to find out what they expect/require.

I have a few questions with ref to the damp proofing, searched all over the net but can't seem to find specifics.

It is a single skin wall, has a damp proof course 20mm up from garage floor, he said the best way is to build a 100mm stud wall on top of a course of bricks, infill with 100mm celotex, I understand this but oviously I need to lay the bricks on a dpc, I have to put in a dpm, do I lap this under the dpm, (wont be any return up the brick)
Also he mentioned a breather membrane between the stud wall and external wall, might be tricky to fit this once stud wall built??
also he said that I need a cavity tray and weep holes between the stud wall and external wall, I understand the need for weep holes but a cavity tray all around?? due to the floor height there is only 20mm between heights.
What do I do with the top of the cavity between, external and stud wall?? does it get left open to the roof or do you need to cap it off??

hope that makes some sort of sense,

any help greatly appreciated.

 

[Ethorathius]

Well i would have thought your external wall would be load bearing so your roof will be sat on it assuming your having a pitched roof so your plate will rest there. So there will be a gap at the top but it will be covered by the roof. The gap gives ventilation to stop damp.