Damp Treatment Before Plastering

[Skavenger]

Hi;

Just ripped out my kitchen and will be getting the walls skimmed.
Before we ripped out the kitchen we suspected we had a damp problem partly due to our next door neighbour building a shed against our outside wall which has left a gap that is always wet, partly because he uses the gap to store all manner of building leftovers, guttering etc.

Anyway after ripping out the kitchen units the walls actualy aren't that bad at the very base the plaster (a very thin coat) has blistered in a few places but the render underneath appears to be sound. We do suffer really badly with condensation in the winter so maybe this is a condensation problem and not rising damp?

Anyway our original plan was to strip back the plaster along the length of the wall and apply a Chemical DPC on the inside wall, because of his shed we cannot access the outside wall sufficiently. Anyway this may not be neccessary as its not that bad, I thought of brushing outs the blistered plaster with a wire brush and painting on bitumen then replastering.

Is this OK and if so anyone recommend a product that I can get from a DIY store such as B&Q, WIKES, Homebase or FOCUS.

TVM

 

[trowelmonkey1]

firstly, your neighbour should be asked to UN-BRIDGE your DPC as it's causing damage to your walls and will continue to, may not be too bad now but over time will get worse and you can't sort the problem properly until the damp problem has been cured.

assuming the above has been rectified, you need to let the walls dry out fully and 'make-good' the blown skim with easifill which you should be able to do yourself, sands down nicely once dry so should get good results, assuming the patches aren't too big

 

[Skavenger]

UPDATE - Well I removed the 1-2mm thick plaster (hey they were pretty sparing when they applied this stuff) a foot above the ground along the external wall.

Using a multimeter I have carried out a basic moisture test and the readings are pretty low 2-3v apart from at the very base of the wall and in the corners where it rises to 4-5v.

The render in one corner seems to have blown so I stripped this back without too much trouble and there were gaps in the mortar in a couple of places through to the cavity - could this have been part of the problem.

Anyway my plan is to remove a brick and rake out the cavity in this area to remove any bridging after which i'll repoint the brick work and then render the walls, however before we replace the render should we coat the walls to damp proof them, someone suggetested bitumen paint which I bought but before I slap it on the length of the wall 1 foot high can you:
1. Apply render onto bitumen painted brickwork?
2. Apply plaster onto bitumen painted plaster?

Other questions:

3. What other treatment should I apply to the brickwork or render?
4. Should I remove the render along the entire length and bitumen as above or use another treatment?
5. Should I run a dehumidifier before patching up?
6. Should I fit an airbrick in the internal kitchn wall behind a cupboard is is this asking for mould?

I would rather not strip of the render to 1m along the entire length and apply a Chem DPC as it does not appear to need it - does it?

I am aware of couple of potential external causes one mentioned above and missing pointing in one / poss both corners which I will also rectify.

Lots of questions I'm afraid.

 

[Skavenger]

UPDATE - Some pictures of the walls before I removed the plaster and some of the render:

The white wall without the pipe was the worst and is where most of the render has been removed. It was not crumbling but had blown away from the wall.

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