DPC help

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windy

windy

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Hi lads

Have a rental property which has a single storey extension. One of the walls have a rising damp problem which is resulting in a wet patch around 4m long and 40cm high along the wall of the kitchen just below the base of the window sill.

Looked outside and the wall is soaking and needs a DPC doin. I have bought some tubes of "dryzone" from TP and hired one of the DPC caulking guns with the metal wand for a fiver. Im happy on how to install the dpc on the outide as it seems striaght forward.

Problem is the bloke at TP said if wetpach coming onto inner wall then i should do the same from the inside of the house to treat the interior wall. To do this i would have to obviously remove a bead of reander to find mortar joints at correct level to inject then render then skim.

I need people to view the house this week to get it rented and i dont really have the time to do the internal plastering.

Is he right or should i try to get away with treating the outside and see if it dries out? If not will i have to revove all backing plaster on the wall or just damp areas??

THanks
 
surely they will be happy that you're fixing the problem unlike alot of landlords? just tell them it will be finished by the time they move in
 
And will someone answer the question

Pointing looks outside

if pointing work needs to be done what mix ratio do u use?
 
windy said:
And will someone answer the question

Pointing looks outside

if pointing work needs to be done what mix ratio do u use?
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Pointing looks outside?
have you checked around the window?
Is it single skin?
what has it been plastered inside with?
rising damp does not exist it has never been found and you will not find it anywhere on the web.
 
Young luke you may well be an master with the ligh saber (Trowel) but me thinks on bricks in water you have much to learn LOL
 
henry said:
Young luke you may well be an master with the ligh saber (Trowel) but me thinks on bricks in water you have much to learn LOL
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Its true you will not find proof of RD anywhere I challenge you to find me solid proof and i will change my mind :)
 
Is this a cavity or solid wall and you say it's 40 cm up from the dpc? If you can drill all the way through to the inside wall drilling the mortar bed then inject this also. You will no that if the plaster is blown then of it comes.
 
flynnyman said:
Pointing looks outside?
have you checked around the window?
Is it single skin?
what has it been plastered inside with?
rising damp does not exist it has never been found and you will not find it anywhere on the web.
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I'd agree with this.

Ground level higher outside?
 
If it's twin skinned and rendered maybe the lads couldn't be arsed beading round the weep vents and smashed them off like we do lol
 
My point is if you stand bricks in water they will after a time soak water into them. I have done a lot of dpc work over the years and have seen water dripping out of bricks when injecting fluid into the bricks. Penertrating damp is due to two things on brickwork 1) the face of the brick has shelled off and morter bed have crumbled over time with weather etc allowing water to find it's way into the fabic of the building. Flynnyman riseing damp is on uk gold .
 
henry i bet it wouldnt travel up through the brick more than an inch a good example is if you look at the bridges in venis have a look at the water levels and it doesnt rise up through the bricks or every bridge over water would be crumbling. Have a look on the web and see if you can find solid proof of rising damp its a myth and is always another problem.
 
has anyone considered the probability judging by the 'remove a skim bead of render' that its bridged..

flynny and the old rising damp argument again...:RpS_bored:

heres one for you flynster...

quick way to see if the damp is receding - draw a pencil line round it yeh?

ive injected walls that have had a damp problem for years, no further treatment other than the injection and hack off and re render with waterproofer...
end of problem..

now your gonna say its the waterproofer that dun it arent you.. :rolleyes)

i give up... :RpS_blink:

although you already know i do agree its rare, and is usually bridging or penetrating or pouring down the skinny little cavity associated with a 9" solid..
 
Chris W said:
has anyone considered the probability judging by the 'remove a skim bead of render' that its bridged..

flynny and the old rising damp argument again...:RpS_bored:

heres one for you flynster...

quick way to see if the damp is receding - draw a pencil line round it yeh?

ive injected walls that have had a damp problem for years, no further treatment other than the injection and hack off and re render with waterproofer...
end of problem..

now your gonna say its the waterproofer that dun it arent you.. :rolleyes)

i give up... :RpS_blink:

although you already know i do agree its rare, and is usually bridging or penetrating or pouring down the skinny little cavity associated with a 9" solid..
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Misdiagnosed in the first place i bet you, and it is never rising damp :)
 
I know there is a bandwagon saying riseing damp is a myth.and a bandwagon who make a lot of money off riseing damp. But let me ask you the question flynnyman why did the victorian builders put slate between bricks and the same today with a plastic strip.
 
theres all sorts of damp penetrating damp water running down walls & ground water pressure its mainly due 2 the morter joints beds & perp joints they act like vains sucking the water up most modern morters have got water proofers in your lot older propertys dident sand & lime or very little cement ie very dry & cant stop the passage of water so they act like a wick ( dryzone) if ifs a cavity the inner skin can be done from the outer skin have a look at dryzone web site or safeguard site :RpS_thumbup:
 
rising damp its a bit of a myth imo its a combernation of the 2 dry bed joints sucking water up & water rising due to sucktion this is why you dont get damp passed 1 meter mark & the walls are soaked at the bottom & damp at the top because the waight of the water pulling back down but this is just my theory :RpS_biggrin:
 
so are soft bricks... the idea is exactly the same, capillary action...
a substrate is porous because there are gaps between the molecules that 'suck' water in..
adding waterproofer to a sand and cement mix fills most of these gaps in..
same way that pva works - 'suction control'...
now off to read flynnys 'link' :rolleyes) but before i do, it seems to me there is more effort expended in disproving rising damp than there has been in proving what is essentially a simple concept...
 
i'm not on either side, i can see where flynnys coming from but on the other hand, if its not rising damp what is it
 
christ on a crutch.... what a carry on :rolleyes)
all that just to find a practical 'documented' example... dunno about that but who goes back and takes material samples after the job? well, assuming the treatment worked that is...
and by 'worked' i mean theres no further sign of damp, but by replastering with a 'dense' (as in added waterproofer) render then how you gonna know?
isnt 'rising' damp just 'penetrating' damp thats come through the floor/dpc/plaster/mortar joints/whatever... the idea is the same yes? capillary action... mentioned on diy not as 'diffusion' (dunno what that is but im guessing its a method of water travelling through a substrate without having 'capillaries')

the silicon injection method -

drill hole halfway into brick, insert lance, form seal with washer on end and apply pressurised fluid until the brick sort of 'sweats' fluid..
yes?

wouldnt work with a lump of steel....

sometimes the fluid runs out of the mortar joints, sometimes it absolutely p'sses out the bricks (cracks etc) but the bottom line is there is a route for water to take a lot of the time... if you fire the lance in, pressurise and nothing visible happened you'd be wasting your time yes?

from the peter cox site -
Damp Proofing | Rising Damp

basically agreeing that MOST 'rising damp' is caused by bridging / penetration / condensation, BUT implying that 'rising damp' is just a catch all term for damp symptoms appearing at the lower half of the downstairs internal wall, HOWEVER, they still treat for it when required e.g failed or non existent dpc in a wall that cannot evaporate the moisture as quick or quicker than it gets soaked up from ground level BRICKWORK...

I like to think of it like this....

if all the other possibilities are eliminated, what remains, however improbable, must be the truth....
(sherlock holmes i think?)
 
henry said:
what about internal 4" walls chris I have seen plenty of them damp .
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im not on flynnys team here, im on the other side mate, although Im not one of these 'yeh its rising damp mate, it wants injecting' nobs...
ive worked for damp proofing companies, came very close to working for peter cox last year (driving licence points f'cked it up) and ive got a reasonable idea of how damp works

4" or 9", same difference, its just that a 9" wall gives you yet another possibility for how the water gets in there... or up there, or whatever :RpS_blink:
 
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