Damp Proofing - Job doesn't appear to have worked.

[Wuckers]

[quote="izalarfin"]paint just comes off the wall even though we used unibond etc,' Explain.

When the plastering over the bricks took place we gave it 6 months to dry out,...in reality it dried with in a few weeks. We wanted to just paint the walls so before painting we applied a coat of unibond....gave it a week to dry and then painted over it.....the paint was good quality dulux, but sad to say 6 months on and it started coming off.

The floor is solid terracotta tiling, been there eons. Are these 6 or 9 inch square ?. They're the 6in

Do you have salt crystals forming and is the new plaster bubbling out in small patches ?. Yes I think so..

I've had a bit more of a look today, it appears confined to these two rooms, there is no guttering (due to the way the roof is pitched) on one wall so it isn't a leaky guttering. I've been to the rooms above them both and there is no damp in either of them (never has been for that matter)

Some of it appears drenched in moisture due to the very high pitched squeal I get from the meter, some of it the meter just croaks in small tones.

Do you get black mould spots ? Nope, nothing like that at all.

[izalarfin]

As said.

really old properties such as yours can be an absolute nightmare to diagnose and treat... ..

Your paint coming off is due to the unibond, if you do a search on here or ask about it in the dec' forum they may tell you a way to fix this.
If the tiles were laid before the fifty's then they are most likely laid on a bed of lime mortar on top of coal cinders that was used to level
up the soil or over a old brick floor that is laid out on the soil and if they didn't cut the new render back an inch above the floor then
the damp could be drawn up the face finish plaster,
the salts that weep from the wall if left will show up as a crystal and if viewed from a side angle will shine or reflect light and by the time
you can see them the plaster has started to bubble and blow off the wall.
Have you had the bricks drilled and the dust put in a moister meter and tested or the new render ?, if not then it would be worth your
while to have this done, if you know a farmer then you might ask if you could used his that he test his grain with.
Drainage around your outside walls is your first place to sort as the quicker you can dry the ground against your walls the less the bricks
soak up.
My house was built in 1860 / 70 and has no dpc and this spring I finished building a retaining wall underground from the footings to one brick above soil level, I done it in class B engineering's leaving a 125mm cavity and caped this slabs ( ask for details if needed / wanted)
this has dried out the walls and the floor which was most noticeable by how much warmer it was under foot.

[Wuckers]

The house was built in 1780....

The drainage is ok on the outside, it runs to a soakaway nowhere near the wall, no puddles are left.

There is another room that has previously been damproofed and it was corkboard insualtion on the walls, the damp has never returned.

In regards to this one room though, I will find the unibond issue and sort that out.

There are salt crystals in attendance but these walls were hacked back to the original brick...surely that would have cured it? Should they not have used a special plaster when making good the walls after injecting them etc?

As for drainage, in the other room that is proving problematic they again hacked it off to bare brick, I had the pipework and washbasin and toilet all removed...they inject the wall but I'm not so sure they got the right place...or the right depth when injecting,,I read up on wykamols sight and I don't think it was put in at the right place.

I think it needs looking at by an expert who can then maybe pinpoint the problem and put their name to it at which point I'll approach the original deamp proofing company and see what they want to say about it but essentially I paid for something that has not corrected the problem and by the looks of it was incorrectly diagnosed and treated.

[Deleted-user-3]

what youre asking for would be an 'expert witness', someone trusted and qualified who will state their findings in court etc...
that'll be chargeable...
the problem with some injection methods can be that the substrate injected isnt sound. In the case of high pressure injection if the bricks are shafted then the fluid just dissapears into the hollows in the wall and achieves nothing in the way of damp proofing the brick. A noticable drop in pressure and the rapid loss of fluid from the container usually gives this away straight away...
cream injection works differently and relies on the water already in the bricks to penetrate the substrate where it crystalises forming a waterproof barrier..
'injection mortar' is another method using a similar principle to cream injection but in the from of a mixed mortar which is more robust than cream, sometimes used on old stone buildings with ambiguous or unknown construction
do you know which method your origional company used and why?
also do you know the origional diagnosis of the problem?
dpc injection should always be carried out above anything that can bridge the dpc, either internally or externally... anything below that is classed as 'wet' and internally, if exposed higher than the floor should be tanked...
both internal and external dpc injection should be at the same level..
double drilling is a method where the internal skin is drilled from the inside then injected with high pressure delivery, then drilled deeper into the wall and repeated... its possible to inject both sides of the wall from one side using this method, but it can easily go wrong as it means injecting blind...

'getting the levels wrong' shouldnt really happen but it does..
following a course of bricks to an opening such as a door, then following them back round the outside might give you a clue?

the only 'special plasters' generally used are 'limelite', used for renovation work, has a built in salt neutraliser and is skimmed as normal
or straight sand and cement render with added waterproofer and salt neutraliser... the waterproofer you find on the shelf down the builders merchant tends not to have a salt neutraliser
There are new products coming on the market all the time but theyre generally variations on the same theme.. the bottom line is, plaster will not stop the damp. the problem needs to be sorted before re-plastering.

there are 2 ways to stop water ingress be it rising damp or penetrative damp.
1) stop the water getting to the substrate in the first place e.g external membrane, fix the leaky gutter, cap and repair the chimney, drop the ground level
2) provide some sort of barrier to stop it coming into the inside of the substrate e.g. tanking, dpc injection, internal membrane coupled with internal drainage system (usually used in basements), introduce a cavity (newbuild houses)


like you said, it needs someone who knows what theyre talking about to have a look...
whether or not theyre prepared to stand up in court and have theyre diagnosis treated as fact will be down to their professional qualifications and the size of your wallet..

[Wuckers]

Thank you for that CWplastering, very helpful indeed.

In regards to the expert report, I had an expert report on other work of the company involved and his opinion held weight with the judge and they lost the case. At that time the damp work they had carried out was still early days and it was still sort of in the process of drying out, but here we are just over a year on and the problem is still very much apparent.

I've applied for the guarantee from the damp proofing company, I suspect it won't arrive and then I'll have to go through the motions of court and experts report.

The core issue is I paid them to fix the dampwork which they assured me they would...but it hasn't actually worked out like that and the damp is still apparent., I don't want blood I just want the issue solved and a damp free environment in those two rooms.