How best to deal with underlay between me & my neighbour?

[benraz69]

Hi, I live in a semi-detached house with an old outhouse attached at the back of the property (neighbours is the mirror of mine). A lot of water has started coming in. Had a look - quite a lot of the slates are cracked, some of them with large bits broken away.

Whilst I’m redoing the slates, I’d like to replace the underlay (it’s got at least a couple of small tears & a few pinholes where I think the previous roofer used too longer nails for the slates).

My question is, bearing in mind the battens & underlay go all the way across mine AND my neighbours outhouse too, how do I finish the underlay over my roof without disturbing my neighbours?

(Her slates are fine, she obviously had them done not too long ago).

 

[catlad]

Plenty of overlap.

 

[datarebal]

If she's had hers done recently then if you are lucky the roofers may have made life easy for you at the join.
Remember they had the same detail to deal with.

 

[benraz69]

If she's had hers done recently then if you are lucky the roofers may have made life easy for you at the join.
Remember they had the same detail to deal with.

Unfortunately not, I’ve already lifted the slates to the join/boundary. I guess the underlay was in better condition on her side.

Plenty of overlap.

Thanks, where’s the best point to cut/finish the old underlay on my side? Over the top of the first rafter I come to?

 

[catlad]

If your not replacing all the felt and only putting a patch in then you will need to unpick the batons and slide the new piece in.

 

[datarebal]

So are you saying ,your neighbour had their roof stripped and re slated without new underlay or batten ? Jeez !

 

[benraz69]

So are you saying ,your neighbour had their roof stripped and re slated without new underlay or batten ? Jeez !

Looks that way, but will confirm later. The battens look in okay condition to be fair. It is only an outhouse I suppose, so maybe they didn’t think the job needed to be A1 (just reread my OP & realise it may not have been clear it was just the outhouse, apologies).

If you’re not replacing all the felt and only putting a patch in then you will need to unpick the batons and slide the new piece in.

Sure, but obviously I’ll still need to cut away the old stuff on my side. Is the best place to do so over the rafter closest to the join/boundary? i.e. presumably I don’t want to trim it halfway between rafters, as the old underlay may sag/crumble below-?

 

[catlad]

Can't you just slide the new felt over the old?

 

[benraz69]

Can't you just slide the new felt over the old?

I could, but then you would see all the old, falling down underlay from below (it’s an outhouse, so the ceiling isn’t lined). We’re hoping to sell in the autumn too, so thought a surveyor might not like the look of that.