Damp proof course - DIY or call the professionals?

[SJRSJR]

I have rising and lateral damp in a party wall due to being on a steep steet and the neighbouring house being three feet higher. It's going to cost £3k for chemical injection and tanking, which I can't afford. I'm capable and am considering doing it myself by hiring a heavy duty drill to bore the holes and injecting thixotropic gel (Tri-Gel) as you then don't need the high pressure injectors. I know a good plasterer who says he can do the sand/cement render. (I'm also aware of the Party Wall Act and that I need to get my neighbour's consent first).
I know I won't get a guarantee but I can't wait until I can afford it.
I read conflicting things so any tips would be appreciated.
Is this a job to be avoided or can it be done by a competent person?
Some say drill the bricks, others say drill the mortar?
Some say that if the wall is already damp a chemical injection will stop it from evaporating?
And if I can't drill from both sides of the wall as seems to be recommended is it a lost cause anyway?

Thanks

 

[noseall]

RISING DAMP.

dodgy words on this forum.

 

[Frederick]

First you really need to make sure it really is rising damp. Safeguard's guide to Rising Damp and its Control has a useful section at the beginning about how to diagnose different types of dampness - see http://www.dryzone.eu/en/useful-literature-about-rising-damp/

If you decide that it is in fact rising damp then you need to decide whether to do it yourself or get a professional in. Getting a professional in gives you the advantage of having a guarantee when you come to sell the house. On the other hand, if you do the job properly yourself you won't have a damp problem so it won't come up in the survey.

P.S. My own experience with using TriGel was not a positive one - the damp proofing effect only appears to spread about 1cm around the injection hole so there are large sections between holes through which the damp continues to rise. I'd suggest you either use Dryzone (full-strength cream) or inject the old way using damp-proofing fluid.

 

[noseall]

rising damp does not exist. just ask softus.

 

[Frederick]

Yeh, we all know what Softus's opinion is

 

[SJRSJR]

I had it inspected and they said it was rising and lateral damp.

Thanks for the tip on the gel. I was wary about using the liquids for fear of it soaking through to my neighbour's plaster.

And I hope this isn't a stupid question but am I right in thinking that if my neighbour's house is three feet higher I should be drilling the holes at that level to create the barrier, and then deal with the damp bleow by tanking?

 

[masona]

Need more info where the damp is, internal or external wall, how high is the damp? Could it be condensation and not damp etc

Interesting links here , here and here

Before you do anything, there's loads of info on rising damp if you do a search here.

 

[markie]

Where's softus when we need him

 

[SJRSJR]

It's an internal party wall from front to rear. The obvious problem is in the kitchen at the rear where the damp can be seen up to 6 ft high - if the adjoining house is 3 ft higher that makes sense and surely lateral penetration is the cause. In getting it checked out by a damp company I'm told that none of the houses in the street were built with DPC and that the damp stretches all the way along the party wall through to the front of the house where the plaster in the hallway can easily be pulled off . Lucikly I'm in the middle of decorating but this has stop me progressing and I just can't afford the additional cost right now, hence the question about DIY.

All my research makes me think it's been correctly diagnosed, but I just don't know if I'm underestimating the skill and knowledge needed to put it right. Is doing the chemical injection yourself that complicated?

 

[Frederick]

The only difficult bit is the replastering. Other than that its just a question of:

1) Removing affected plaster.
2) Applying tanking slurry from the bottom of the wall to just above desired DPC level.
3) Drilling holes in mortar and injecting Dryzone cream or damp-proofing liquid.

Whichever system you use, you are really trying to damp-proof the mortar as the damp usually travels through the mortar (unless you have very permeable bricks). The reason people often inject damp-proofing liquids into the bricks is that you need to get a good seal around the injector when using a damp-proofing liquid. If you try to do this in the mortar course most soft Victorian mortars will crumble when you try and tighten the injector seal.

 

[masona]

It's an internal party wall from front to rear. The obvious problem is in the kitchen at the rear where the damp can be seen up to 6 ft high

Have you checked all the plumbing pipe is not leaking?

You may also have a main cold feed buried in the wall?

Do you have lead pipe, after approximately 70 yrs, the lead can get pinholes leak?

 

[SJRSJR]

Thanks Frederick, can you recommend a good tanking slurry?

masona - there aren't any pipes on that side of the kitchen but it's always possibe my neighbours have a leak. I will check.

 

[Frederick]

I tend to use Vandex BB75 tanking slurry because that's what my local Jewsons stock and because I've never had any trouble with it. I've been told that Thoroseal is an acceptable alternative, although I've never tried it.

 

[ginger100]

hi, can you not ask the firm that surveyed the property to give you the instruction you need as they know your circumstances and are the best source of advice for you.
We ain't all baduns tyring to do you youk now!

 

[mikeyd]

Ginger: Check the date of the last post before you reply..

(easy mistake I know)