After what seems to be a never ending torrent of rain I have noticed an wet/damp patch on the wall in our lounge. Its about four feet in the are and localized to an area about 8in wide.

The wall that it has appeared on is an external wall. I have checked the pointing (lime) and the bricks in the surrounding area and all looks to be fine.

Never noticed a patch in this place before 😕

I am guessing that it will dry out on its own but any thoughts on how I might help stop this happening again?

Its only noticeable due to a slight color change in the paint (darker)

Could try posting a picture of it with a bike in the foreground on here. You’d get some advice then.

Is there anything on the outside of the wall which might cause water to run against that part of the wall ? e.g. shed, guttering downpipe etc

RealMan – Member

Could try posting a picture of it with a bike in the foreground on here. You’d get some advice then.

😆 Couldn’t get it to show 😆

allthepies – Member

Is there anything on the outside of the wall which might cause water to run against that part of the wall ? e.g. shed, guttering downpipe etc

No, nothing. Its a clear piece of wall.

I guess water could be getting in further up but I cannot see where this could be 😕

Leaking roof, coming down the cavity wall somewhere?

Sure it wasn’t your kids (if you have kids) messing about and getting water on the wall but it not drying out?

I had damp patches from a leaky rook, such that water came down (internal) cracks in the wall (stone) and produced damp patches in areas where the external wall was fine.

woody2000 – Member

Leaking roof, coming down the cavity wall somewhere?

Non cavity walls 😕

Plus it seems a strange place to have come to rest. No sign of anything further up in the same room or the one above 😕

The age of your house may make a difference. Is it solid or cavity wall?

Bricks can become (more) pourous as time goes by. You can get a silicon sealant to paint on which may help if its solid wall. If its cavity then there may well be something bridging the cavity . not sure how you get that out easily

I would hazard there is a bridge in the cavity and the moisture penetrated the exterior wall (simply by having rain hitting it for an extended period), across the bridge and onto the ultra-absorbent interior plaster.

Geey-jay beat me to it 🙂

The house is cavityless and was built in 1881.

I’m guessing that the bricks in that area maybe succumbing to age?

I will look into a sealer.

Jeez there is always something.

Hope you get it sorted. I have a patch in the hall of my place, interior wall adjoining next doors hallway, no brickwork to get wet, no drains, no gutters, no cavity, appears halfway up the wall after rain and has no damp below, above or either side of it. To say I’m baffled would be an understatement.

joolsburger – Member

Hope you get it sorted. I have a patch in the hall of my place, interior wall adjoining next doors hallway, no brickwork to get wet, no drains, no gutters, no cavity, appears halfway up the wall after rain and has no damp below, above or either side of it. To say I’m baffled would be an understatement.

Ditto hope you get it sorted too.

A couple of suggestions have been to use a sealer paint on the interior but I worry that this would just mean that the patch would relocate 😕

Must just move a plant in front of it or something…

Hope you get it sorted. I have a patch in the hall of my place, interior wall adjoining next doors hallway, no brickwork to get wet, no drains, no gutters, no cavity, appears halfway up the wall after rain and has no damp below, above or either side of it. To say I’m baffled would be an understatement.

We have a similar thing too, halfway up a first floor landing. No sign of damp on exterior wall but a patch that comes through in very cold weather. I am assuming it is a bridge radiating the cold from outside (if you can radiate cold air????) and causing a condensation patch.

something like this

Don’t get too carried away though it stops the house breathing so you don’t want to paint the whole house in it

I’ve worked on several conservation jobs and I would not recommend using any kind of silicon sealant on the outside as this may introduce other problems. Your house was designed to be breathable, using lime mortar and it’s been fine without silicon up until now. If there’s water penetrating the wall from outside you need to identify the cause, usual suspects tend to be leaking roof, gutters, downpipes etc. Look further away than just directly outside the damp patch as water may track away from the penetration point before it appears on the inside. Check if you have any hot / cold water pipes around that area that may be leaking. Another thing to check is the condition of the pointing outside. Has the face of the pointing crumbled and need remedial work? Also check for damaged stones / bricks that act as a ledge to hold water. If you are re-pointing make sure you use a lime mix. Do not use anything that is cement based as this will cause a lot more problems. Same principle applies if its render on the outside. For more info look at Ty Mawr website (lime products). There very helpful (if you can get through to them) if you need advice on any of their products.