Is Ceiling and Wall Dampness due to roofing or chimney ?

[Leakyroom]

[see images below]

We had new guttering fitted recently thinking that would resolve damp marks on ceiling and upper interior wall. Since then we applied Damp Seal to plaster, sized it ready to paper then after rainfall the plaster bubbled in areas on image - the original areas of concern.

I have checked loft as far as possible, all seems dry. There are eaves trays and new felt at eaves. Ridge tiles also new. Chimney has been capped, re-pointed, with vent brick present, flashing seems intact.

Any ideas how to solve this would be much appreciated !

Ceiling/wall dampness

• Leakyroom
• 28 Jul 2014
• 1

After using Damp Seal and Size, bubbles of moisture still forming under Size in area above...

chimney from outside.

• Leakyroom
• 28 Jul 2014
• 1

New guttering, dry loft, flashing around window has been checked - dampness on interior wall

 

[ree]

Where you redline the stains on the chimney breast area(?) is where you must carefully examine the ceiling and brickwork above in the loft - pull away all insulation etc. and use a powerful light.
Look up at the felt and determine that its not too saggy or too short from the eaves or back gutter?

You could even stay in the loft, and observe while someone else plays a hose and water tests the stack area.

Externally, could the damp be puddling on the projection to the left of the c/breast? Is that area fully flashed including the cheek of the c/breast?

Back gutters on stacks are notorious for introducing leaks - only close inspection and pics will tell what condition the b/g is in.

Pointing and flaunching are also suspect.

Has the flue(s) been swept recently? Soot can cause a form of dampness inside the c/breast.