Leaky wall?

[N_i_c_k]

Today I discovered a damp patch had appeared on an interior painted wall. The patch is about 2ft across and half way between floor and ceiling, in a bungalow.

In the roof space I can't easily get closer than about 15ft from where the wall meets the roof but from what I could make out there is no sign of water coming in there - not conclusive though.

The outside of the wall looks like it might be the culprit. The wall is brick and has (or is supposed to have) cavity wall insulation. The mortar on the outside had some gaps and holes in it about where the damp patch is, which I hastily attempted to fill with some Geocel "The Works" sealant.

If the leaky wall theory is correct then I'm guessing the wall needs repointing? Could it be something else?

Thanks

[Cash]

Water will penetrate through the bricks (unless they are engineering bricks) as they are rather porus (especially with the amount of rain we are having at the moment) - hence the cavity wall system, which allows any penetrating water to run down the back of the outer skin to below the damp courses and soak away.

From your description, I would suggest that at the point of the 'patch' you the classic case of either a dirty wall tie (a snob of comp on it) and/or a lump of compo or broken brick bridging the cavity and allowing the water to penetrate across to the internal wall.

The only real cure, is to open the cavity at that point and clear it out - or you if you have a guarantee on the cavity insulation, claim off that to get the job done.

As for repointing - possibly a waste of money at this stage, until you confirm that the cavity isn't bridged. For the reasons, see my first paragraph

HTH

Cash

[tabbypurr]

OP only need repoint where mortar is missing or falling out. Whatever you do will take a good while to see results. I'd start with an inspection of all the likely causes & fix the mortar gaps - with sand/cement not a sealant.

NT