Injection damp proofing, has it actually been done?

[Steven Fitch]

Hi

I have recently had a local company out to carry out some damp proofing work on some internal brick walls. They are at the stage now where they say so far they have completed:

- Taken off the plaster to around 1m high.
- Drilled the two lowest courses of mortar approx every 100mm.
- Applied the injection damp proofing.
- Re plastered The Walls

All they need to do is re attach the skirting boards.

At this point i have decided to have a look at the work and from what i can tell, no injection has taken place, All of the holes which are still visible are empty and i can easily stick a screwdriver in them to approx 3inch deep, scrape away a bit and brick dust comes out.

Common sense and a quick images search on google suggests they should be full with something resembling a silicone seal.

Basically my walls look like this (image from google, not my actual walls)

and i was expecting them to look something like the left hand side of this?

Any advice appreciated.

 

[^woody^]

The injected material is a liquid or cream. It soaks into the wall, and that's how it works. The holes are empty, and just filled externally for weathering.

 

[ree]

Did they "re-plaster" the internal walls with gypsum plaster or a sand and cement render?

Was the re-plastering kept from contact with any solid floors?

Were the backs of any wood skirting examined for fungal damage? In older properties wood plugs (inserted in the brickwork) were used to fix skirting to. They have to be removed during remedial work.

 

[Steven Fitch]

Did they "re-plaster" the internal walls with gypsum plaster or a sand and cement render?

Was the re-plastering kept from contact with any solid floors?

Were the backs of any wood skirting examined for fungal damage? In older properties wood plugs (inserted in the brickwork) were used to fix skirting to. They have to be removed during remedial work.

Yes there is a few inch gap between the new plaster and the floors which will be hidden by the skirting.

They used a dark coloured (sand and cement i believe) under the plaster.

The skirting is off and still present at the site so i will have a look at the back of it, i dont recall there being anything obvious on the back of it.

 

[theprinceofdarkness]

The fact that they did not patch the holes shows a poor job. When I had mine done (which worked 100%!), two holes were drilled in every brick, one half way through, the other half way into the other (inner) course of bricks. A wand with a pressure seal to the hole was put in and the silicone pumped in until you could see it sweat through to the front of the brick. The inner course used a different probe and guess work was used as to when the inner brick was saturated.
All the holes were patched up with colour matched mortar, which was only a fair attempt.
The reason to replaster is that hydroscopic salts may have worked their way up the wall driven by the original rising damp. If these are not sealed in, theoretically the moisture in the air can cause them to appear on the surface of any decoration. Ordinary sand and cement and plaster will not stop this. Just slow it down.
Frank

 

[gregers]

they probably used a water bourne solution hence why the drilled the mortar bed and not the bricks,there are various methods of dpc injection.and differing chemicals.