Roof leaking along joint with older roof

[tomevery]

hi there, i have inherited a roof problem that i didn't discover until too late. I bought my upper flat in a 4 in a block (See photo). my side (on the right) has been re-roofed with tiles and my neighbour's house has the original slate roof (i think).

As visible in the photo, my roof is slightly raised leaving a step down to my neighbour's roof on the left. Added to this, there are 4 unused flues i think you call them sticking up between the two roofs.

one month after moving in, we decided to have a good explore up in the loft, not done previously as it was only partially floored. it was then that we found the rolled up carpet soaked in rain water directly underneath the where the two roofs join.

The rain is basically getting in (presumably in multiple areas) and running allong the wooden planks underneath the tiles and dripping down into the loft. where exactly its getting in (and why) i'm not exacty sure.

Has anyone seen this / anything like this before or suggest any fixes / costings for repair?

Thanks and any feedback / suggestions greatly appreciated!

 

[Alastairreid]

Are the 4 vents unused?

you should have a bonding gutter between the 2 roofs, hard to tell from the pics if you have.

 

[tomevery]

Hi
The vents are not in use.
It doesn't look like there is anything resembling a bonding gutter in place. Just what looks like cement filling the gap?!

 

[Stevetheroofer]

I would remove the vents and strip back slates and tiles to allow the fitting of a bonding gutter. Cost wise I would allow £400 plus scaffold( if access is poor for ladder working)

Steve

 

[Alastairreid]

How do you know your neighbour is not using the vent on their side?
as it looks like they have a loft conversion.

The caps missing from the top vent as well.

 

[tomevery]

I've asked the neighbours and they say their vents are not in use. . The one at the top just has a different type of cap.

 

[scottishslater]

looks like a bad attempt at a join one side looks like fiber cement slate the other tiles they have taken the tiles over the fiber slate by six or seven inchs and just blocked it off with mortar.