Extension roof basics

[23vc]

Hi
Couple of questions on my extension roof, any feedback appreciated as always
Plannung to use trusses and rear plane will continue across new trusses, front will be stepped in/down a bit as is common.
Tiles are concrete interlocking, Mendip or similar

1. Existing gable overhang has what looks like the old asbestos soffit underneath, I was hoping to just leave this alone, and pop a couple of nails from the first new truss into the existing timber barge board? Making sure the truss sits at the right height for the new battens to carry the roof across

2. Was hoping not to strip or re felt any of the existing roof as it's not in bad shape, where the roofs join at the back (same plane carries across onto new roof) is there a minimum felt overlap, or can I pretty much leave the existing alone?

3. At the front I was planning on using lead fixed up underneath existing barge board then dressed down onto the new tiles, seems the easiest way and seen others done that way (not sure what question I'm trying to ask here but any tips welcome)

Cheers
John

 

[^woody^]

1. Yes that's ok. Make sure that the verge is not kicking the battens up though. If it is, it will need to come off.

2 You'll need to lap to the second rafter, if the felt is firmly fixed to the rafter nearest the gable. If the felt at the verge is in poor condition, then lap to the third rafter.

3. That's ok if the lead will be tight up against the wall, and secure behind the barge board. It could slide if not

 

[23vc]

Thanks woody that's a massive help.
I did think the battens may be kicking up a bit at the existing verge but I'm struggling to tell, they sit on top of the barge board, but looking at it from the back garden there's no visible kick up to the tiles. Then again with these clunky shaped tiles it's not that easy to tell
There is no undercloak it's currently got verge cap thingies

 

[23vc]

Sorry meant to add, this soffit sheeting running under barge board is really thin, like 3mm thick. It's grey and got that dotted texture on the back. Any ideas how likely it is to be asbestos? Not sure of how to get rid of it if it is, but I'd be tempted to soak it with the hose and gently pursuade it off

 

[^woody^]

Asbestos cement sheet is normally thicker than 3mm, more like 6mm or 1/4" for the old fogeys and very rigid.

3mm and bendy will likely be asbestos free modern stuff.

Generally, lift the laths up, take the mortar off in lumps, remove any nails holding the undercloak to the timber beneath, then slide the undercloak out. Use water and a mask, but outside is relatively low risk for this work on asbestos cement.

Verges invariably kick up, and need checking when you come to line the tile laths through.

 

[23vc]

Thanks woody. Understand that cloaked verge always kicks up but there is no undercloak on this verge, the board I'm on about is nailed to the underside of the barge board. I'll get some tiles off and have a closer look