Dryzone Dampcourse

stebiz

I have hacked off plaster to my house and asked for a DPC company to come and inject dryzone. He came today and did front room but would not do backroom 'Hi front room done i can guarantee that room for you but the back room and extension no damp injection will solve the problem as someone has removed the wooden floor and install a concrete floor no matter what you do to the walls damp stains Will start to show through at low level"
The concrete floor has a membrane. Can somebody enlighten me please? Help.

Doozergirl

You didn't need the first injection.  

Can you post photos of the affected areas, inside and out and with some context around them rather than just a picture of a damp patch. 

A photo of the whole outside wall is also important. 

🙂. 

stebiz

It's a mid terraced and the walls did look very discolured, especially at low level. Here's a pic of the front room showing a failed dpc. The white is the dryzone. I haven't got one of the rear room which is the same but a solid floor with vinyl floor tiles, installed with a membrane in 1980's.  

neilmcl

stebiz said:

I have hacked off plaster to my house and asked for a DPC company to come and inject dryzone. He came today and did front room but would not do backroom 'Hi front room done i can guarantee that room for you but the back room and extension no damp injection will solve the problem as someone has removed the wooden floor and install a concrete floor no matter what you do to the walls damp stains Will start to show through at low level"
The concrete floor has a membrane. Can somebody enlighten me please? Help.

As mentioned, you didn't need any DPC injection. Brickwork gets damp because it drawers water from a source, eg, from water penetration or condensation and then isn't allowed to breath and dry out properly. More often than not a chemical DPC can actually damage brickwork over time and can also lead to damp issues of it's own. It's one of the biggest rip offs in the building and restoration industry. 

Can we have a picture of the wall from the outside?

stebiz

neilmcl said:

stebiz said:

I have hacked off plaster to my house and asked for a DPC company to come and inject dryzone. He came today and did front room but would not do backroom 'Hi front room done i can guarantee that room for you but the back room and extension no damp injection will solve the problem as someone has removed the wooden floor and install a concrete floor no matter what you do to the walls damp stains Will start to show through at low level"
The concrete floor has a membrane. Can somebody enlighten me please? Help.

As mentioned, you didn't need any DPC injection. Brickwork gets damp because it drawers water from a source, eg, from water penetration or condensation and then isn't allowed to breath and dry out properly. More often than not a chemical DPC can actually damage brickwork over time and can also lead to damp issues of it's own. It's one of the biggest rip offs in the building and restoration industry. 

Can we have a picture of the wall from the outside?

It's a party wall.

stebiz

What's the thoughts on the new plaster? Plasterboard okay?

neilmcl

stebiz said:

neilmcl said:

stebiz said:

I have hacked off plaster to my house and asked for a DPC company to come and inject dryzone. He came today and did front room but would not do backroom 'Hi front room done i can guarantee that room for you but the back room and extension no damp injection will solve the problem as someone has removed the wooden floor and install a concrete floor no matter what you do to the walls damp stains Will start to show through at low level"
The concrete floor has a membrane. Can somebody enlighten me please? Help.

As mentioned, you didn't need any DPC injection. Brickwork gets damp because it drawers water from a source, eg, from water penetration or condensation and then isn't allowed to breath and dry out properly. More often than not a chemical DPC can actually damage brickwork over time and can also lead to damp issues of it's own. It's one of the biggest rip offs in the building and restoration industry. 

Can we have a picture of the wall from the outside?

It's a party wall.

How old is the property, can we assume it's not a cavity wall? Might be worth speaking to your neighbour to see what's on the other side.

Personally I'd hack all of the existing cement plaster, let it dry out and replaster with a breathable lime plaster.

stebiz

120 years.

floppydisk1

Lime plaster all the way, as said earlier , chemical DPC is a no no in 120 year old house and total rip off. I hope it was not plastered with cement based render.  I have seen 2 - 300 year old houses  houses injected and plastered with gypsum or cement based plaster and it all gone pear shaped in year or 2...  Lime plaster will allow wall to breath and dry out slowly on its own, with no chemicals and no cement to keep water in.

Doozergirl

And the photos of other affected wall? Inside and out.  

Are there any air bricks ventilating the under floor area of the photographed room?  

Is your neighbour's side still a suspended floor? 

The problem isn't going to disappear even on that wall.  I would suspect that either the subfloor isn't ventilated, causing a build up of condensation underneath which spreads up the room edges, or there could be a leaking chimney above, if there is one nearby.  

FreeBear

stebiz said: What's the thoughts on the new plaster? Plasterboard okay?

There will be an original DPC just below the floorboards - If you take a look around the outside, you may well see a course of hard engineering bricks, a thin layer of slate, or possibly the edge of a bitumastic layer. That injected stuff is way too high to do any good, and as soon as you plaster, it will bridge the stuff anyway. The guy who did that work is a muppet.

The pattern of brick says that it is a solid brick wall (consistent with a Victorian build). Plasterboard and/or gypsum will turn to mush after a few years, so you want to be using a (pure) lime plaster. Anglia Lime do a premixed chalk plaster with added polyester fibres which can be applied up to 20mm thick then finished with a fine plaster - No where near as cheap as PB+gypsum, and you may struggle to find someone willing to do the work. But as long as the exterior hasn't been messed around with, a lime plaster will last a long time.

Just don't go slapping on the waterproof render/plaster that usually accompanies chemical "injection" or you will be hacking it all off again in 5-10 years time.