Leadwork on single story extension. Window help

[Bcarey]

Hi there

I have had a single story extension built by a friend I am a plasterer myself so have helped him out. The roof is all but complete barring the lead work.

Problem I have is there is only a 2 course gap between roof line and bottom of above cills and I am not sure how to run the lead can I go tight to underside of cill?

Thanks in advance
Billy

 

[freddiemercurystwin]

Good practice is a 150mm upstand in the lead so 2 courses.

Provided that the dpc under the windows, if there even is one, is also in this course ie the lead should not be above the dpc. Otherwise (albeit pretty unlikely) any moisture or rain that has got through the outer skin higher up will trickle down the dpc and could get trapped in the wall behind the lead though this is only really possible at each end of the windows.

We don't know what age or type of construction the house is?

Nine times out of ten where I am in the country if its a cavity wall, Building control insist on fitting a cavity tray where the new roof abuts the wall.

 

[Bcarey]

Hi the house was built in the late 1920s and is a 9inch solid wall if that helps?

 

[freddiemercurystwin]

Ahh OK, no dpc under the window then so stick you lead under the cill as you planned.

 

[Bcarey]

Thanks for the help what size lead would you use?? Obviously the six inch upstanding but how much going onto the roof?

Thanks

 

[Nige F]

www.leadsheetassociation.org.uk/apron-flashings

 

[joe-90]

Apron flashing? I know a housewife that used to do that. Very popular with the lads, I can tell you.