EllwoodJT

Ok not going with shingles now partly because of your reply. Many thanks it's good information. I'm going with an interlocking fake slate it goes down to 10°, much dearer but I'm happier. Next question tho.... On top of 6" rafters spaced 450mm I'm putting t&g osb board 18mm do I need a membrane on the inside under the osb? (the interlocking tiles use their own adhesive backing 1m wide all BS EN Iso credited stuff) obvs I'll be using 100 kingspan from inside. Any suggestions appreciated. Many thanks so far.

Does anyone know if there are any regulations on using bitumen roof shingles on a new extension? I don't mean floppy Wicks shed roof shingles I mean proper ones like they use all the time in Poland, Russia etc where lower temperatures and potential bad weather are likely. I'm building an extension with roof either side approx 1600mm wide by 4000mm projection with glass in the middle approx 4500mm. Its a pretty low pitch 13°. There is an interlocking composite fake slate but I wondered if building control would object to shingle style tiles if properly fitted? Thanks in advance!

Thanks again. How deep a slot vertically? Do I need to go thru to the cavity or just 40mm ish? Do I need to wedge dpc in the virtical slot? How often should I position weep holes above the tray? Cheers

Finished floor level of house and therefore extension is green line and dpc on house is black line. Stainless crocodile wall starter will obviously be where blue lines are roughly. How do I overlap into house dpc? Do I carefully cut the mortar joint exposing some of the house dpc, do I additionally apply some sort of sealent? How do I cut vertical barrier, how deep etc and overlap it with the horizontal dpcs below it? Many thanks in advance.

So far thank you I will take photos and do a sketch tomorrow. ?

Could someone advise me on the correct procedure for overlapping the dpc on my extension. The house dpc is one brick below floor level. 1- Do I / can I, use 300mm dpc as a cavity tray from the extension floor level down to match the house dpc level (one brick) if so how many weep holes should I provide ? 2- how do I tie this in with the house dpc, do I need to chase very far in to overlap extension dpc and house dpc? 3- How should I approach the virtical dpc/starter kit, how far in should I chase the wall etc. Many thanks in advance! I can post pictures if necessary.