Joining roofs

[23vc]

Hi
I need to continue my existing roofline across onto my new extension trusses. It's concrete interlocking tiles. I know I need to lap the new felt over the existing by a couple of rafters worth, but I can't work out how I'd do that without ripping the existing battens off and damaging the existing felt, and basically end up ripping the whole existing roof off.
Can you gently pursuade the old battens off and slip the new felt under them? Can't see how unless you get the nails out completely? Any pointers much appreciated, I'm keen to leave the existing roof alone as much as poss as I've not got the whole thing scaffolded

 

[catlad]

Prize the old batten up with a crowbar half inch
then with a bolster chisel hit the old nail between
the baton and the rafter too crank it a little, then you
hit the baton back down and the old nail should stick
up a bit giving you the option to pull it out.
You are then free to slide your new membrane in.

 

[23vc]

Thanks a lot for that, I was thinking it was something along those lines but that's given me more confidence to crack on, cheers

 

[noseall]

If you happen to spilt any battens (and where cutting back to the next rafter is a problem) then just fix a support batten beneath the split one and fix to two rafters.

 

[23vc]

Cheers noseall, how is the support batten fixed to the rafters, skewed screwed? As I'm assuming it runs between rafters not above

 

[23vc]

Sorry ignore my previous reply I misunderstood, I've now realised the support batten sits below going down the roofline still on top of the rafters

 

[noseall]

Sorry ignore my previous reply I misunderstood, I've now realised the support batten sits below going down the roofline still on top of the rafters

Correct. Because of the angle at which the tile sits, this support batten can sometimes be chunkier than a tile batten, should it need be. We will regularly fix a support batten at these old-new junctions simply because old laths (battens) are often thinner and brittle.