Perished bricks? Damp proof course being replaced...

16 Oct 2009
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United Kingdom
I'm having a new damp proof course installed at my Victorian house, as there is penetrating damp, which is causing the plaster to come off the wall inside.
The damp proof installer has removed the plaster, but he says that the brickwork has been damaged and is soaked, so bricks probably need replacing.
However, there is render up to about waist height on the outside and he needs to remove it, in order to make a complete analysis.
He says that the outside render is also acting like a sponge.
Essentially he is saying that he thinks there are 'perished' bricks which will not dry out, or if they do, they'll just get wet again and the damp will come through the wall.
Of course, all this means that we have to write a blank cheque and funds are short right now...
I've only heard of brickwork being damaged by spalling (the face of the brick falling off due to water damage and freezing), and I'm not sure if that would happen under rendered brickwork.
Can anyone confirm?
Even if the brickwork was damaged in this way, would that still result in the bricks soaking up water, considering that the surface of the brickwork is rendered?
Has anyone seen this problem previously?
Any advice would be appreciated.
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Render plinths, which is what you describe, are notorious for creating damp difficulties. Typically, the render has to come off, just like the interior plaster.

If you had used the Search facility on this forum to read up on a massive archive of info and pics of just what you describe you would have been able to pose your question(s) with far more helpful information.

Perhaps do a search and then come back with info and pics?
Well if Stephen Fry reads it from a script it must be true.

Meanwhile back in the real world.

It would be reckless to give a definitive diagnosis on the strength of the limited information. Dampness is never straightforward and often the result of various problems acting together.

It does rather sound like your installer is being economical with the truth. A remedial injected damp proof course will do nothing to prevent penetrating damp.

The external render soaking up water like a sponge may not be such a problem. That is what it is supposed to do. It is only generally a problem if it bridges the damp proof course. In which case all you need to do is cut a horizontal joint in the render to stop the bridging.

If they are saying that the render needs to be removed because it is a cement rich hard render that is trapping moisture within the wall that is a different matter. I would suggest that removing it will cause extensive damage to the brickwork so best to leave well alone and just treat the source of the moisture getting into the wall.

I would get a second opinion from a reputable contractor or surveyor.
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Too late...he has removed the render and there is indeed damage to the brickwork. Whether or not it was damaged beforehand, I don't know.

Basically, I think we're screwed now, but I'm going to ask him to halt the work for the time being.
I have a slightly similar problem. My render plinth has started coming away from the wall by itself, so water was getting behind and blowing the faces of the bricks out.

I intend to cut and stitch the damaged bricks, but wonder what to do with the exposed bricks below the damp proof course. Leave them uncovered? I see some houses with black paint along the bottom of the wall, perhaps that's what they've done in a similar situation?

I suspect that any damaged bricks, have been damaged under the render, due to water absorption and cracking in the winter as it freezes.

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