Damp Problem on a Solid Brick Gable End

[glock339]

Hi, I have bought a small semi-detached cottage that I am busy renovating (total DIY amature by the way), which has a problem with damp on it’s gable end. The front and back walls are cavity brick, but the problem gable end wall is just a solid brick wall with no cavity. It seems like the damp problem has been a long on going thing with this wall as it looks like the previous owners had tried various things to remedy it. Such as chipping off the bottom meter of the origional plaster work and running some kind of render internally along the room with about a meter return on the adjoining walls. I don’t think this worked though as I remember the wall paper was in a bad state in these areas before I removed it. I think a lot of the water is run off from next doors concrete path which runs along side my house and is aprox 150mm above my suspended wood floor level. The concrete path in question dosent have anywhere to run off aprt from my and next doors walls and always looks a bit damp and mossy. I tried to add some pics of the wall etc but I can't seem to figure out how to up load them???

Now then, I also want to insulate this gable wall internally for heat efficiency but I’m concerned about just covering up this problem wall without solving the damp problem first. I have been told by a couple of people I could get away with putting in some air bricks in the external wall which on the one hand would give me some extra heat loss in the newly built cavity but would help with the trapped damp. I have already begun the studding for the internal insulation and left a 30mm gap between the timber and the wall.

So would the way I’m going work if I stuck in a couple of air bricks or do I need to have a big re-think? Any help and ideas are much appreciated!!
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[ajrobb]

I think a lot of the water is run off from next doors concrete path which runs along side my house and is aprox 150mm above my suspended wood floor level.

Sounds nasty. I wonder how long the path has been at that level? Does it slope towards your house or your neighbours? You'd hope the path would be 150mm below your damp course, which would be 150mm below your floor level. Could your neighbour drop the path by 450mm?

I think my big worry would be that the bricks and mortar are strong enough to stay wet. It needs to be built like foundations.

Now then, I also want to insulate this gable wall internally for heat efficiency but I’m concerned about just covering up this problem wall without solving the damp problem first. I have been told by a couple of people I could get away with putting in some air bricks in the external wall which on the one hand would give me some extra heat loss in the newly built cavity but would help with the trapped damp. I have already begun the studding for the internal insulation and left a 30mm gap between the timber and the wall.

So would the way I’m going work if I stuck in a couple of air bricks or do I need to have a big re-think? Any help and ideas are much appreciated!!

I assume your joists run front-to-back and don't sit in the wet wall. I'd open up the new cavity to the underfloor, put some air bricks at the top of the cavity and maybe more air bricks under the floor front and back. Don't worry about the extra heat loss, just add a few mm of insulation. I'd remove the new plaster/render from the bottom of the wall inside - it might contain concrete and/or gypsum, which will stop the wall drying out.

You say you've started the studding. Are you using treated timber at least? Heritage House have suggested galvanised steel.

 

[glock339]

Sounds nasty. I wonder how long the path has been at that level? Does it slope towards your house or your neighbours? You'd hope the path would be 150mm below your damp course, which would be 150mm below your floor level. Could your neighbour drop the path by 450mm? icon_lol.gif

Lol yeh I'll just ask if they fancy dropping the path! I haven't stuck a bubble on it but it dose look fairly level, might have a proper look if I get chance.

I think my big worry would be that the bricks and mortar are strong enough to stay wet. It needs to be built like foundations.

Hope so!!

I assume your joists run front-to-back and don't sit in the wet wall. I'd open up the new cavity to the underfloor, put some air bricks at the top of the cavity and maybe more air bricks under the floor front and back. Don't worry about the extra heat loss, just add a few mm of insulation. I'd remove the new plaster/render from the bottom of the wall inside - it might contain concrete and/or gypsum, which will stop the wall drying out.

Yes the joists do run front to back and I have trimmed back the floorboards about 30mm to allow air to circulate under the floor and wall. I have also removed all of the plaster/render, although if I'm honest it was mainly because it was about 50mm thick and diddn't want to loose even more length off my room!

Ahh good I was planning on sticking some air bricks at the top of the cavity, glad to hear I'm on the rite track anyway. I was also going to put some lower down on the gable end, just above the path level. Is this worth doing?

You say you've started the studding. Are you using treated timber at least? Heritage House have suggested galvanised steel.

Well I gave it 1 coat of fence/shed preserver and then a coat of external timber stain/preserver, basically just what I had handy at the time Hope this will be OK? Afraid my tiny budget has been taking a good kicking lately so I'm scraping together anything I can use!

Thanks very much for the reply by the way

 

[glock339]

Ahh, figured out how to add pics!!!

Bit late now but better late than never, will hopefully get some time this week to crack on with the air bricks etc.

My dodgey diagram of the wall and next door path:

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A not so good photo of the path and alleyway:

[/url][/img]

 

[masona]

Is your next door neighbour wooden flooring the same level as yours?

 

[ajrobb]

Or use the BBCode:

Untitled

• glock339
• 20 Apr 2010
• 2

Untitled

• glock339
• 20 Apr 2010
• 2

 

[glock339]

Is your next door neighbour wooden flooring the same level as yours?

No their floor is above mine and the path. I've been told that my cottage and the one that's attached to mine were amongst the first dwellings in the village, built for dairy worker families. The other houses in the street came quite a bit later on and it appears the one next door to me was built a foot or two higher, the street is on a slight slope.

 

[masona]

Do you know where your next door footing level is?

 

[glock339]

Only just realised I had another reply sorry!

No I don't know exactly what level it is just that is defo above mine, sorry for being a bit vague!

 

[ajrobb]

A big problem with damp bricks is the risk of spalling (frost damage). I'd check the condition of your bricks above your neighbour's path. Ventilation to dry the bricks from the inside can be important in protecting them from damage.

When you get a heavy downpour, check to see if water is running/standing against your bricks. You'll still have a problem of splashing wetting the bottom 2 courses.

If the concrete path is made with ordinary Portland cement, it could prevent water from getting into the subsoil. Old lime concrete will let water through.

 

[glock339]

Cheers for the info ajrobb I'll have a sneaky peak next time it chucks down, shouldn't have to wait to long knowing the great British weather! I'll also try and measure up properly where the path level is up to internally on my wall and see if the dampness is worse above or bellow it etc.

I was just wondering the other day would a little drainage channel running along side my house on the path help? Its quite likely next door wouldn't be to up for me putting this in the side of their path though I suppose!