A plasterer has just finished a chemical DPC at my house and replastered. One of the walls was really bad but it's all done now.
This same wall, a few days later is still damp (he used Limelite Renovation for both layers). I'm just wondering how long I should wait until for this patch to dry out.
Is there any paint-on damp proofing that I could use to cure this remaining problem?
Thanks,
Ed.
Could be damp for a while, at least a month, depending on the thickness of the plaster and the weather etc. Did the guy not tell you how long to wait?
Rob
He just said "give it a while". Hmmmm...
I did notice that the bricks were still damp before he replastered. It happened to be the worst bit out of the lot, anyway. The bricks above it had turned white from the treatment and seemed mostly dry. The ones lower down are the ones still wet.
Is it worth gently heating the room to see if I can find out whether the treatment's worked?
Supposing it didn't work is it possible to drill into the wall and reapply some more of the DPC chemical without having to knock off the plaster?
Cheers, Ed.
Rob Summers wrote:
Oh dear. Most injected DPC are just a method for ripping off punters. It's very rare that they fix any kind of damp.
Not surprising. A damp wall will take weeks to dry out, but if the cause of the damp was wrongly identified, it will never dry out.
I don't know this plaster, but a full scratch and finish coat will take many days to dry out anyway, plus however long the wall takes to dry out.
No, at least not without accurately identifying the cause of the damp, and not at all if it's condensation (which is a very common cause).
ouch. From your comments it sounds like you've been got.
just forget about it. If its still damp in 6 months, the cause hasnt been fixed. Brick walls take months to dry out. At this point theres no knowing if the dpc man did anything that would make the wall dry out, only time will tell. Often they remove soil and vegetation from the outer side of the wall, which fixes the problem.
Painting things on wont draw the water out. Quite the opposite, any barrier only slows evaporation down.
I see no connection between the 2.
sure, but entirely pointless. A DPC has nothing to do with damp problems in almost all cases.
NT
So can anyone tell me how to diagnose a damp interior wall please?
Can condensation really be the cause of very damp bricks. What is the standard solution for that?
Thanks,
Ed.
Andrew Gabriel wrote:
The only DIY method I know is to fix a small piece of glass onto the plaster with a circle of putty or plasticine so that there is a gap between the plaster and the glass. If there is moisture in the trapped air then it will condense out on the inner surface of the glass. This test will confirm damp but doesn't tell you its source. But as your walls have been re-plastered very recently there is no point in doing this until the new plaster has had chance to dry out. Didn't the installer tell you not to paint/redecorate for at least 6 weeks?
Seems unlikely. Condensation often causes damp plaster and mould growth.
Well, there's
And there's what the damp proofing companies will tell you, which may or may not be correct.
Firstly, what made you think it was damp to start with? What times of the year was it more evident? What's the construction of the wall? (type of bricks, mortar, thickness?) What's on each side of the wall? (type of finish, room, outdoors?) What's on the top of the wall? Any chimney flues?
Ventilation, avoiding uneven heating, avoiding discharge of moisture.
| |> Can condensation really be the cause of very damp bricks. What is the | |Yes. | |> standard solution for that? | |Ventilation, avoiding uneven heating, avoiding discharge of moisture.
Better insulate the cavity, so the inside leaf gets warm, and condensation does not form.
Uh-oh. Another one falls victim to the chemical DPC scam....
Cavity wall insulation is normally blown in through holes drilled in the outside wall. Normally straightforward subject to a survey and grants are available.
The usual trick with a chemical DPC is to render the inside with waterproof mortar before the plaster skim. Which does, of course, get rid of damp showing on the inside of that part of the wall. But doesn't cure the cause - anymore than a chemical DPC does.
This is an internal wall, though.
Phil Anthr> > Could that be done without replastering and/or is it straightforward? >
Then it's either rising damp which the dpc should cure (claim under the guarantee if it doesn't dry out in the specified time). Or you have a plumbing leak. Is this a kitchen or what?
|Could that be done without replastering and/or is it straightforward? | |Dave Fawthrop wrote: |> On 03 Aug 2006 07:04:42 GMT, snipped-for-privacy@cucumber.demon.co.uk (Andrew Gabriel) |> wrote: |>
|> |In article , |> | "Ed_Zep" writes: |>
|> | |> |> Can condensation really be the cause of very damp bricks. What is the |> | |> |Yes. |> | |> |> standard solution for that? |> | |> |Ventilation, avoiding uneven heating, avoiding discharge of moisture. |>
|> Better insulate the cavity, so the inside leaf gets warm, and condensation |> does not form.
It is very straight forward, it is done from the outside by commercial companies. The government has offers if you are on benefit etc. You just get three quotes and take the lowest, or best.
|This is an internal wall, though. | | |Phil Anthropist wrote: |> "Ed_Zep" wrote: |> > Could that be done without replastering and/or is it straightforward? |>
|> Cavity wall insulation is normally blown in through holes drilled in the |> outside wall. Normally straightforward subject to a survey and grants are |> available.
Then insulation will not work.
Yep, it's a kitchen but the damp is in a about four different places and not adjacent.
I live towards the bottom of a steep hill. Could it be water underneath flowing downward?
Stuart Noble wrote:
If this is ground floor and the damp doesn't affect the external walls, you have to be looking at some kind of rising damp or a leak. Either way the damp should be worse at the bottom and not go any higher than 1 metre. Is this a solid floor?
Most of the ground floor is wooden floor boards but there are two tiled floors where I guess it seems to be a solid floor underneath.
Stuart Noble wrote:
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