# Interior wall flaking



## Stoort (Jul 30, 2012)

I have a small village property in the Algarve hills and my question concerns interior moisture. The wall next to the front door of my casa is deteriorating to the extent that the white plaster is flaking off leaving some holes in the wall. I don't think there is a damp course in these old traditional homes. It's only affecting about an area 2ft square. What is the remedy? I'm no builder but I'm guessing the area will require to be ragged and filled with plaster? Is this likely to be expensive and can I do it myself?

Thanks


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## Strontium (Sep 16, 2015)

Hi, 

Could you post a photo of the said wall and damage? When you say traditional I take that as meaning field stone - as in dry stone wall construction - with infill of mud/mortar for stability then a render for sealing and additional stability.


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## Stoort (Jul 30, 2012)

some of the images.


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## baldilocks (Mar 7, 2010)

The reason there are no DPCs is earthquakes. If your house is in a zone that might be subject to seismic activity there is a danger that, if a DPC is in place the house could slide off the foundation.

We had the same problem and, in many cases, around here they tile about 1 metre up the wall, which can look quite attractive. What they did in this place is cover the lower part of the wall with a plastic imitation of tiles - it looked bl**dy awful and was poorly installed, even being held in place with rusty nails.

The solution we used was to hack off the old plaster. Wash down the area with clean water to remove any salts that have been carried up the wall. Allow it to dry fully. Get some PVA glue (white glue - cola branca) dilute this with about 40-50% water (mixed well) and brush it onto the area allow to dry thoroughly (if the surface is extremely absorbent, apply a second coat) - this will leave a layer of clear plastic on the surface. Then re-plaster and paint with a plastic emulsion paint.


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## Strontium (Sep 16, 2015)

Emmmmm.

If the walls are of traditional field stone and infil construction and not block/brick then it's not possible to have a DPC because of the construction technique also the traditional wall has to "breathe" so will absorb moisture when it;s humid/damp then release the moisture when its less humid/damp so, after a period of time, the moisture content of the wall is equivalent to the moisture content of the surrounding air. Putting an impermeable layer on the lower part of such a wall will prevent the moisture evaporating, similar things happen if the mortar/render used is Portland cement based with no lime content - Portland cement based mortar doesn't breathe where as lime based mortar does.


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## RichardHenshall (Jul 26, 2009)

It looks to me like a rising (or penetrating from low level) damp problem that has already been 'fixed' by re-rendering the area below the tide mark (or applying an impermeable filler to smooth that area). This is encouraging the damp to rise further.

Is the external ground level too high or is there another external source of water penetration that could be fixed before refinishing the wall with a breathable material?


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## Strontium (Sep 16, 2015)

^^^as he says.

That looks like render visible on the corner but in picture 2 it looks like the upper part is painted render - as is traditional - but the lower part is smoother suggesting it has had additional work because there is some moisture getting in and being trapped somehow. I've seen this problem often, if you can get a local builder, ie one who had worked on many older houses he/she will have also seen this all before and usually will find where the moisture is getting trapped and remove the repair and an over lap area (as the salts may have concentrated in this bit) and re render with the correct render. which matches the upper wall. A days work plus standard materials so maybe 100 euro.


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