Roofing Question

Damp patches on chimney breast wall

Every time it rains i have some damp patches that seem to appear on the chimney breast wall in the bedroom. Most of the patches seem to be low down on the wall. Any suggestions?

7 Answers

Best Answer

Hi there,

There are a few possibilities that could be causing your damp patches.
First port of call would be to have a roofer call by and check whether your leadwork is all intact and performing its proper function, on older homes in particular the back gutter (bit where roof meets chimney) can be perforated by a slipped tile or slate. The flashing above the backgutter can also move around and become dislodged over time due to the expansion and retraction in hot/cold weather.
Another option to look at is if you have cowels installed (the tin hat looking things) on any open pots. Rain can come down an open chimney pot, particularly if it is no longer in use and so therefore sees no heat and never really gets to dry out properly.
My final and probably the most common problem that i come across is that the chimney needs repointing (grind out all of the mortar joints and replace it with new) and if this is the case it usually pays to have a complete reflaunch at the same time (flaunch is the shaped layer of mortar that holds pots in place and closes off top of stack).

Hope i have helped?

Northampton Lead

Answered 11th Oct 2011

Northampton Lead

Member since 15 Dec 2009

Hi there, first step is to take a look from inside the attic. to see If you can see any day light.If yes you will need to contact a roofing contractor to take a look from the out side of the roof,to see if any tiles have slipped,or lead work has been dislodged.Kind regards.

Answered 13th Oct 2011

TRM Roofing/Builder

Member since 23 Apr 2008

Check to see if you have any open chimney pots, if so fit rain/bird guards, dont block of ventilation, you also need vents inside.
Check front and back lead aprons, flashings and soakers.
Check for any missing/broken tiles.
Check pointing.
You could have a blockage in that position, and damp is traveling through.

Answered 11th Oct 2011


Member since 29 Oct 2008

The lead has failed in you roof check this

Answered 12th Oct 2011

JGB Contracts

Member since 5 Nov 2010

No feedback

If the Damp patches are on the ground floor it may be rising Damp but if it is up the stairs I would get the flashing checked.

Answered 11th Oct 2011

JB Home & Commercial Solutions.

Member since 29 Jun 2009

Hi it could be a few things either lead flashing needs re newing or broken tiles or cement flaunching or even pourus bricks which may need water sealing

Answered 11th Oct 2011


Member since 27 Nov 2010

Hi, sounds like either the lead flashing of the chimney is failing or the chimney may need capping. Thanks

Answered 11th Oct 2011

m.s construction

Member since 15 Jul 2010

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