Hi, I have a ground floor flat and have Rising damp in a few walls including the party wall. Cash is a bit tight so I want to fix this problem in the cheapest way.

Would it be possible to simply drill into the mortar through the actual skirting board instead of having to remove them, and then inject damp proofing cream? I realise I would need to find where the mortar is by drilling small test holes through the skirting board first.

The plaster is firm but just a bit damp, would it be possible to leave it on as I assume it will dry out as would new plaster?

Thanks in advance.

Phil

Hi Phil,


what you propose would not work long term.

Once plaster has hardened from it's liquid state when it is applied, if you re-wet it as happens with Rising damp it causes all of the salts to come to the surface. This is why the effected plaster is normally removed, then the DPC is installed and when the wall is dry the plaster is re-applied.

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DIY | Donnas dream house

chances are its plastered to the floor... i.e. the plaster on the walls is in contact with the floor and the 'rising damp' youre experiencing is probably just bridging...
seeing as skirting board is £1.50 per linear metre, sand is £1.50 per bag, cement is 3 quid per bag and a tub of waterproofer is around 12 quid..... your biggest expense is the experienced knowledgable tradesman your gonna need to do the job..

or not, if you feel confident...

besides, a tub of filler is around a fiver... skirting board is cheaper...

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http://www.peterborough-plasterer.co.uk/

Thanks for the replies and advice guys.

CW, you say



I don’t know much about this but why should the damp come from the wood floorboards into the plaster? I assume that’s what you mean by bridging?

Also I’m trying to determine if it would be cheaper to fix the damp myself with injection cream and just pay to have the walls replastered.

So if for example it would cost say £500 to have the full job done then if I fix the damp roughly what should it cost to have the walls replastered only?

Any ideas of cost would be appreciated.

Phil

the wall isnt built on top of timber, it extends down below, under the floor and will probably be sat on what is known as a brick footing... either way, if the plaster bridges any dpc in place (and this is a very common occurence) then 90% of the time all that is required to cure the problem is simply chopping off the bit that bridges the dpc.

however, should you genuinely have a rising damp problem, your still going to need to remove the skirtings and remove any plaster there anyhow...

so... step 1) - remove the skirtings, if the wall is damp, chances are the skirting is rotten, ill be gobsmacked if it isnt...

remove the plaster behind the skirtings...

be absolutely sure of the cause of the 'damp' or better still, make this step 1 before you do anything... you say the plaster is a bit damp, any salts? mildew? are you sure its not just condensation? might well be... is the floor well ventilated underneath? have you got air bricks front and back? are they blocked?

price for replastering? depends on the area.... but to hack off to 1m high, re-render with dricoat undercoat plaster and skim finish? about 50-60 per linear meter will put you in the right area with a minimum start cost of say £250...
its a 2 day job however much there is to do, dricoat takes 24 hours to cure before you can skim it

£500 to hack off, drill and inject, then replaster isnt going to go very far at all...
maybe 2 small walls one side only....

hacking it off yourself and disposing off the rubble would help, as would drilling and injecting with an injection cream... leave just the plastering to the plasterer and youll probably get that linear metre rate down quite a bit, but dont forget its a 2 visit (day) job + materials, and dont expect a guarantee if you inject the walls yourself...

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http://www.peterborough-plasterer.co.uk/

The skirting boards seem to be solid. There are 3 terracotta air bricks at the front of the room opposite the damp wall which don’t look blocked.

11 days ago I painted the entire walls magnolia, as it was a bright yellow previously.

There was a small area about 6” diameter on the bedroom wall which backs onto the lounge wall where the paint was flaking off, so I scraped off the loose, sanded it, applied some undercoat then emulsioned the walls when the undercoat was dry.

Now 11 days later there are 2 parts of the lower wall that look damp/wet but didn’t when it was yellow so don’t know why it’s decided to look damp now and the window has been open a bit all night and wide open (more or less) during every day. It’s as if the paint hasn’t yet dried. The plaster is solid but coldish, no salts. BTW the building is about 115 years old and I don’t think there is a cavity in the front bay window walls.

The £500 was just an idea to try and apportion how much the plastering only would cost in relation to the £500 if you see what I mean.

So……… I’m confused! lol

no worries, your in the right place mate...
its still not necessarily rising damp as such its a massively complicated subject...
'scraped off the loose' does sound a bit like salts, which does actually point to rising damp so i'll base it on that for now.. before you go mad though.... air bricks at the back of the building will ensure decent airflow...
then you got the cold air from below penetrating the lower 6" or so up the gap behind the skirting..

its a bit of a sherlock holmes thing is damp... 'eliminate whatever is impossible, and whatever is left, however impossible, must be true'...

so lets just say youve actually got rising damp...

its a hack off, metre high. (note the full stop). obviously skirtings removed, just replace em.

then, drill and inject following manufacturers instructions to the LETTER

then replaster, however, be aware of hygroscopic salts... google the words hygroscopic+salts then come back...

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http://www.peterborough-plasterer.co.uk/

There is an air brick at the rear of the property. This is just a 2 bed ground floor flat.

I googled hygroscopic salts so sort of understand what that is.

I just cant understand why the repainted wall looks damp/wet when it didn’t before it was painted.

I have had estimates and of course everyone sticks their damp meter everywhere ad says I have damp. Like you need a meter to see it!

Problem is everyone has a different idea as to how to fix it!

If the full job cost say £1000, how much do you think the plastering only would cost?

Phil

take me about 1/2 an hour to drill an inject 4m of wall...
take me about 8 hours to replaster said wall...

your call..

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http://www.peterborough-plasterer.co.uk/

Hmm so on a say £1000 job £58.83 for drilling & injecting & £941.17 for plastering.

Not of course forgetting removing the old plaster & skirting boards.

It’s not worth doing part the job myself in that case.

Thats what the man said!

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By eck! ©

Hi Phil,

Go with the guys who are members of the Property Care Association. They're the ones who are trained, audited and kept accountable - they're likely to have given the correct diagnosis.

Hope it all works out for you.

Ben