Rising Damp

Steve_xx

I assume that the path to the front door has been raised? I assume this due to the fact that the airbrick is at ground level and therefore heavy rain will penetrate the holes in this airbrick and will end up in the house.

The wall has been rendered and I note from the pics that the other airbricks are set back into the wall. Rain may be running into them and then running down the inside wall. I would suggest that the pointing around those airbricks needs to be angled at 45 degrees, like putty holding a piece of glass in a window frame. This will ensure that water is drained outside, as it looks to me like it's possible that rainwater could be ducted indside.

The line which juts out at the bottom the wall may not be the damp proof course, it may just be the way the house is built. Do you know whether you have an injected damp course or is it a plastic or bitumen course? If it's an injected course you will/should be able to see where the holes to inject it have been drilled in the wall. If you cannot see these holes then it looks like you may have 'bridged' the damp proof course. The next question is where actually is the damp proof course. Is it at or slightly above the line in the bricks that you mentioned, or is it below the airbrick that is at ground level?

Is the damp patch on the inside anywhere near the floor level airbrick on the outside?

Suzy_M

You can't really solve the damp problem until you know where the dpc is so using the image that shows the street -

Is the unrendered brick wall opposite yours a house wall?

If so is the house identical / similar in age, design and/or materials as yours?

If it is closely examine your neighours wall and you may be able to see where the original dpc should be. I can see there is no blue engineering brick course so look out for what looks like the edge of roofing felt between two layers of bricks. This should give you some indication of where your original dpc should be. - Or the brown rubber plug holes if it has a injected chemical dpc.

If you can't see plugs or the "roofing felt" look even more closely and you may be able to see if there is a difference between the bricks used at or near ground level and a bit higher. If there is a difference the lower bricks may be engineering bricks (they'll be much harder and denser) and would have been used below ground up to the dpc level.

If the wall opposite is not identical /similar to yours have a look around the neighbourhood for a house like yours that hasn't been rendered and see where the dpc is on that.

george1010

Id agree that your DPC has been bridged. We have found in our experience that your dpc level in most cases would sit underneath your airbrick.

The airbrick is there to allow airflow under your sub floor. Have you noticed any bounce to your floor area.

Course of action

Install new dpc to bottom of your wall. If possible install a french drain along your side of the wall. Your rendered section on the wall should have a bell mouth drip batton above your airbrick (just above your new dpc). Inside the house hack off defective wall to 1m in height and rerender with a 2 coat sika 1 fine sharp and cement 3:1 mix.

You may even find that your wall has been rendered with bonding which is no good for external walls.

more information on the above can be found at:

www. atruss .co.uk/high_ground_levels

ATRUSS PRESERVATION London damp proofing specialists

red40

Another problem you have along with the DPC being bridged is that the DPC level is only around 75mm above the path. The distance between any floor level and the DPC should be 150mm.

cyclonebri1

Looking at the wall opposite your house, by the brick bond it appears to be a non cavity wall property, ie, the wall will be 9" or double brick. Just as likely, even more likely, to be penetrating damp than rising damp. The thinning of the wall for the socket outlet won't have helped either.

Try an exterior waterproofing solution as a 1st option, but rain water will definately be entering the wall via the air brick if there is no liner in the wall at that point. I would hack out the airbrick to ensure it's redone properly, , :beer:

keystone

George, Red, Cyclone

I should think that its been fixed by now. This thread is 16 months old!

Cheers

cyclonebri1

keystone wrote: »

George, Red, Cyclone

I should think that its been fixed by now. This thread is 16 months old!

Cheers

Don't you just hate it when threads get ressurected like this, even when you know2 you are right,;):rotfl::rotfl::rotfl: