Damaged Cob wall

[Guest]

Caps lock is activated.

[David Gardner]

Hi-a  friend has a listed cob house and boundary wall
Parts of the surface of the wall, which has a tiled top, recently fell away in the torrential rain and strong wind we had last week
see attached photo-in total about 1 square metre
In addition to the visible damage there is a large void behind adjacent parts of the wall,
on average about 100mm deep,
but no hole right through the wall
so in effect the damage extends to 2-3 sq metres
but it is basically dry due to the tiled capping-although this needs some attention
 
The purpose of this email is to seek your advice as to which of your products I should order for her
together with the cost, including delivery to Exton, Devon and any repair advice or
for you to do the work
 
regards
David Gardner

[Kevin]

Hello David,
Thank you for your enquiry.

From looking at the picture and from your description, the render on the wall has blown. 
This could be due to two reasons:
1 that the wall has been rendered with cement, which is common but wrong, which doesnt adhere to cob and also doesnt allow the moisture in the wall to escape as it doesnt allow it to breathe.
OR that probably through the capping or through cracks water has got behind the render and pulled it away form the wall.

Although a large area has collapsed the void you describe behind adjacent sections is also ready to fall down.  If you tap it you will find that it sounds hollow.
The solution is to remove all the blown render then re render with 2-3 coats haired lime mortar and then a top coat of unhaired to match the existing finish.  I would also suggest checking and repairing all the capping as that is very likely how the water got in it.
It is hard to give you a price without seeing the wall, as we need to establish just how much render has blown and needs replacing.  We would be happy to come out and have a look and then give you a price to carry out the work, but we would have to charge you a small amount for petrol and time which we would knock of the price should you give us the job.
If you would like to discuss further please do not hesitate to give me a call and we can arrange a time to come and take a look.
In the meantime I would recommend you cover as much as the wall as possible with a tarpaulin as if it continues to rain and the cob gets soaked the wall could easily collapse.

Be happy to discuss further

Kevin Miles
Sublime Renovations