Chapter one
Shared ridges on the Bilsham and Burndell terraces
Cottage terraces built for the engineering works have stood for over a century, and each roof leans on its neighbours.
The Victoria County History records terraces of cottages built in Bilsham and Burndell roads in the late 19th and early 20th centuries for the employees of the engineering works. Whether or not a given row has been re-covered since, the shape of the roof has not changed: a single long ridge, a party wall between each pair of houses and, usually, chimney stacks that sit astride the wall and serve two homes. That arrangement makes a terrace roof behave differently from a detached one. Water entering beside one stack may appear as damp in the neighbour's bedroom, and a repair on one slope has to meet the covering of the next house cleanly, without a step or gap at the boundary.
At a glance
- Terraces date from the late 19th and early 20th centuries
- Neighbouring roofs share ridges, walls and stacks
- Removing a chimney from a party wall needs notice

1.1 The stack, the flashing and the party wall
The weak points on a terrace are the places where something rises through the roof or ends against it. Every chimney stack carries flashings, which are lead turned into the brickwork and then worked down across the tiles, with a tray or gutter behind. The brickwork can also be a problem: crumbling pointing lets water into the stack, which then comes out of the ceiling below. We check each stack from a ladder where it is safe, and from the loft side too, and photograph what we see. If a stack needs rebuilding, our chimney repairs page explains the options, and costs vary with access and height.

1.2 Before you take a chimney down
Building Regulations approval is always required to take down a chimney breast, as the breast is part of the structure. Where the breast or stack is on a party wall, GOV.UK lists chimney removal as notifiable work: the neighbour is served notice before the job starts, and no reply from them cannot be taken as consent. On a terrace that is the normal situation, not the exception, so we raise it at the survey. A stack that is merely leaking can usually be repaired without any of this, which is a smaller job and one we recommend whenever it properly solves the problem.
Where a Yapton terrace roof tends to let water in
| Spot | Fault | Answer |
|---|---|---|
| Shared stack | Open pointing, split lead | Repoint, redress lead |
| Party wall abutment | Lifted flashing, cracked cement fillet | New lead flashing |
| Long ridge | Cracked bedding, loose tiles | Re-bed and fix with clips |
| Rear gutter | Blocked outlet, sagging run | Clear, refix or renew |






