Usual damp issue

[shiningliao]

Hi,

Damp issue on the wall. Picture first as it explains quicker and better.

Untitled

• shiningliao
• 11 Nov 2013
• 1

House was built in 1930s with solid wall. There are damp problem along the pathway to the garden. After a bit of research on internet and investigation, I have found the following problems:

1. External wall was rendered by using cement which trap the water inside the wall.
2. High external ground level. (The ventilation hole in the picture actually been raised up in the past, that ventilation hole is above the indoor floor level)
3. There are DPC in the past but seems not working properly.

So, I am seeking for advice to resolve the problem.

 

[shiningliao]

I found the hollow rendering on the external wall. So I taken them out easily and it revals damp issue. However, I am not sure if the water come from ground or from above (rain water soak in via crack gap)... or both.

The plan for this part of problem is to use lime mortar rendering so that it can hide the ugly damaged bricks and also let the wall to breath.

One thing I am not sure is. How low I should lime mortar render it to? As low as old cement rendering?

 

[shiningliao]

After taken out the old cement renedering, I see the old DPC. It still have empty holes there. Is this normal? I thought DPC will inject chemical and fill the holes.

This pictures shows clear empty holes on the wall.

Untitled

• shiningliao
• 11 Nov 2013
• 1