GLead flashing and lead sheeting should be used to weatherproof the junction between the chimney and the roof.

- If the chimney is built of brick, the lead flashing should be lapped a minimum of 150 mm (6 in) over the top of the brickwork and should extend down the sides of the chimney at least 150 mm (6 in).

- If the chimney is built of concrete, the lead flashing should be lapped a minimum of 100 mm (4 in) over the top of the concrete and should extend down the sides of the chimney at least 100 mm (4 in).

- If the chimney is built of stone, the lead flashing should be lapped a minimum of 100 mm (4 in) over the top of the stone and should extend down the sides of the chimney at least 100 mm (4 in).

Lead sheeting should be used to weatherproof the junction between the lead flashing and the roof. The lead sheeting should be lapped a minimum of 100 mm (4 in) over the top of the lead flashing.

Chimney repair and maintenance

Due to the very nature of there job Chimney stacks are usually exposed to the elements and are exposed to the winds. We find that most clients forget about there chimney as it is on the roof and out of your eyesight, the issue is that if you do not pay attention to your chimney and have regular maintenance checks then loose pieces of masonry go undetected and they can become unstable, these loose pieces will need replacing at the earliest signs of deterioration to avoid a full repair.

Chimney leaks

The common Causes of Chimney Leaking:

- Rain Going Straight In from the Top: A chimney cover makes sense to most people. Not only does it keep the rain out, but keeps birds, animals and debris out.

- Cracks in the Chimney Crown: The chimney crown is the cement part on top of the chimney. Most crowns have small cracks. Water freezes and thaws in the cracks all winter long, year after year, forcing small cracks to eventually become big cracks.

- Leaking From the Inside Out from Condensation: Gas fumes are very low temperature and have a lot of moisture in them. These fumes can start condensing on the inside of this too-large, too-cold old chimney, literally soaking the bricks and keeping them moist all the time.

- Chimney Flashing: The flashing is what keeps water from going into the place where the brick structure comes through the roof (or otherwise comes close to the roof.) There’s a fairly large gap between the bricks and the roof and water will pour through that hole if it’s not sealed up.

- Leaking Bricks: Bricks and mortar both pass water, and often lots of it. The problem here is the same as with the crown- the freezing and thawing all winter long with the resulting damage which causes leaks in the house.