Damp in internal wall

fdl8

southcoastrgi wrote: »

if it's black mould it's not rising or penertrating damp it's condensation & lack of ventilation, OP if you want to pm me with your email addy I'll send you a very good fact sheet

Thank you - I will PM you

ruben93watson

I agree with @Ionkontrol. Get in touch with an independent damp surveyor to produce a report, not a damp proofing contractor.

fdl8

I'm arranging for another two companies to come take a look - one I sourced from the Property Care Association website .

I had a more in-depth reply regarding the internal wall:

[FONT=&quot]Upon speaking to our Damp Proofing Contractor he explained to me the main reason for the raising damp to the internal wall is due to the internal walls being built off the same foundation/sub base as external walls which are subject to the same ground tensions allowing dampness to rise by capillary attraction where no physical damp proof course exists or where the damp proof course has broken down due to the passage of time.

[/FONT]Does that make sense to people in the know?

uk_messer

fdl8 wrote: »

I'm arranging for another two companies to come take a look - one I sourced from the Property Care Association website .

I had a more in-depth reply regarding the internal wall:

[FONT=&quot]Upon speaking to our Damp Proofing Contractor he explained to me the main reason for the raising damp to the internal wall is due to the internal walls being built off the same foundation/sub base as external walls which are subject to the same ground tensions allowing dampness to rise by capillary attraction where no physical damp proof course exists or where the damp proof course has broken down due to the passage of time.

[/FONT]Does that make sense to people in the know?

It's just more crapola. You don't turn up stick a meter in a wall and then decide you need a 4k injection treatment without lifting a single floorboard to even see whether a DPC exists or where the dampness is coming from.

As for black mould, that can still be from rising damp combined with poor ventilation. The most common reason is poorly paved exteriors which have been built too high, sometimes above the DPC. Also many have had the lower pitted bricks rendered over for cosmetic purposes which then bridges over the DPC.

fdl8

I've got an independent surveyor coming to look at the house next Wednesday - at a charge of £85 - so it will be interesting to see what he has to say.

fdl8

The independent surveyor has been and has said the situation is even worse than the other two companies have stated. He agrees that the internal wall needs to be done (as does pretty much every downstairs wall) but he went further to say that the rear of the house needs to be re-rendered due to cracks. So we have rising damp as well as issues with cracks in the render allowing water to come in. I fear the next quote is going to be substantially more than 4 grand!

He also spotted signs of woodworm in the floorboards but advised that I can treat this myself with insecticide from B&Q.

GolfBravo

IMHO before you spend any more money go to this website http://www.heritage-house.org/ and read about damp and condensation in old buildings.

AlexMac

If it was me, and unless the place feels or smells damp; I'd ventilate as much as poss. over this summer, heat and ventilate well this winter, and meanwhile, while its still warm and dry weather, strip wall-paper from vulnerable areas, sponge the visible mould with bleach or fungicide then do an initial quick redecoration job, using ordinary 'breathable' matt emulsion paint on the walls (not impermeable 'vinyl' emulsion).... and then sit back and see.

If after a year you really have excessive damp, get the work done then

Externally, I'd ensure
-no build up of soil against walls,
-that any air-bricks are clear so they ventilate the sub-floor below the floorboards (and maybe add sub-floor ventilation if absent) and
-no leaking or splashy gutters or downpipes (probably more important than re-pointing);

100-year old houses inevitably get a bit damp but are incredibly tolerant and built to breathe. Ironically, modern waterproof external cement renders can cause more problems than they solve, by preventing drying out!

Given that there are only 3 sources of damp; rising, penetrating or atmospheric (condensation/poor ventilation, etc), if you give it a year, the worst thing that will happens is that the damp persists. This will mean either
- there really are problems of rising damp due to deteriorated DPCs, and/or
- that over the years, damp wall-plaster has absorbed mineral salts from the brick or soil below and become 'hygroscopic' (more prone to absorb atmospheric moisture or condensation)
- that water is penetrating from splashes, gutters or (perish the thought!) plumbing leaks.

But I bet it will dry acceptably

The reason that so many of us are suspicious of the experts is that if you stick a damp-meter in anything some damp will register!

Or go down the engineered route; strip, inject, waterproof/render and replaster; then wait til your neighbour moans if the damp migrates to 'their' side of the party wall! Good luck!

whatatotaljoke

fdl8 wrote: »

Hi

The survey flagged it as a potential issue. The first contractor went in before the purchase was complete, the second after we had moved in. The quotes are pretty much the same give or take a couple of hundred quid.

Water does pool outside some parts of the house in heavy rain but I don't know if/how that would affect the internal wall.

The house was built around 1910 so I don't think it will have any DPC.

It does not matter if a property has or hasn't got an original DPC. Water can only rise 3ft above the water table or ground that is saturated.

If anybody gets told they have rising damp how has that been proven?? By a so called damp meter? That is no more than fraud. To say any property needs work they need to prove the house has a rising damp problem with carbide testing. Damp meters are picking up surface moisture which is irrelevant.

You have a humidity problem which needs to be reduced - if you actually do have rising damp then your one of the only people that has

whatatotaljoke

AlexMac wrote: »

If it was me, and unless the place feels or smells damp; I'd ventilate as much as poss. over this summer, heat and ventilate well this winter, and meanwhile, while its still warm and dry weather, strip wall-paper from vulnerable areas, sponge the visible mould with bleach or fungicide then do an initial quick redecoration job, using ordinary 'breathable' matt emulsion paint on the walls (not impermeable 'vinyl' emulsion).... and then sit back and see.

If after a year you really have excessive damp, get the work done then

Externally, I'd ensure
-no build up of soil against walls,
-that any air-bricks are clear so they ventilate the sub-floor below the floorboards (and maybe add sub-floor ventilation if absent) and
-no leaking or splashy gutters or downpipes (probably more important than re-pointing);

100-year old houses inevitably get a bit damp but are incredibly tolerant and built to breathe. Ironically, modern waterproof external cement renders can cause more problems than they solve, by preventing drying out!

Given that there are only 3 sources of damp; rising, penetrating or atmospheric (condensation/poor ventilation, etc), if you give it a year, the worst thing that will happens is that the damp persists. This will mean either
- there really are problems of rising damp due to deteriorated DPCs, and/or
- that over the years, damp wall-plaster has absorbed mineral salts from the brick or soil below and become 'hygroscopic' (more prone to absorb atmospheric moisture or condensation)
- that water is penetrating from splashes, gutters or (perish the thought!) plumbing leaks.

But I bet it will dry acceptably

The reason that so many of us are suspicious of the experts is that if you stick a damp-meter in anything some damp will register!

Or go down the engineered route; strip, inject, waterproof/render and replaster; then wait til your neighbour moans if the damp migrates to 'their' side of the party wall! Good luck!

Mould grows on distilled water - condensation. So it can not be rising damp.

Be aware when you ventilate a property in winter - cold air contains moisture so you may make your property more damp. Never dry clothes in doors and use extractor fans.

Injected DPC's are a total waste of time - if you managed to actually find rising damp then you need to tank the wall.

Damp specialists? Not one specialist proves the work needs doing. They all come out for free and give quotes for thousands