DPC Completely Missing in a Section of the Back Wall

Postby dannyp1313 » Mon Nov 25, 2013 8:57 pm

hello all

im currently trying to correct my wrongly layed patio area. its was put in above the dpc. I decided to remove aco drain on back wall and 1st row of flags. I needed to dig down so I was below dpc and airbrick and re-lay aco to carry off rainwater from patio area. I am then going to build back up to where patio is so then I will have a 6" gap to back wall.

but heres where my problems began.

I have dug away the said channel but a section of my back wall has NO rows of brick below ground. the dpc goes 3/4 across my back wall then stops. then there is a thick concrete base which im assuming is the original kitchen floor and under that is just clay.its about 1.5m long. then the bricks and dpc continue. dpc is black slate type. house built 1920- 1930.

when I first bought the house the kitchen was very small and on the back wall had a small area that jutted out into the back garden and this is where the cooker was. outside was a brick outhouse around the jutting out bit of brickwork. the outhouse became knackered so I pulled it down. the builder who did my new kitchen knockthrough came back to remove jutting out bit and make it flush with back wall. this area is where the dpc is missing.

I havent noticed any damp patches or smells inside from this area but the whole wall had been dot and dabbed plasterboard when kitchen knockthrough went ahead. theres a full row of floor and wall units there now with full height granite splashbacks now

how do I go about by fixing the missing dpc on outside

thanks for any help

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Joined: Sat Oct 19, 2013 11:26 pm


Simply Build It

Postby welsh brickie » Tue Nov 26, 2013 11:24 am

you will have to drill and inject the wall with dpc fluid
welsh brickie
Posts: 2160
Joined: Sat Apr 12, 2008 7:54 am

Postby dannyp1313 » Tue Nov 26, 2013 7:41 pm

thanks welsh brickie

never done a dpc before so I have some questions.

the original dpc stops at the slab of concrete so I cannot continue the direct line to the other side. shall I go 1 row above but overlap the 2 ends of the original dpc, hoping to create a seal?

which is the best product to use? theres so many available on the net???

I have a double brick solid wall. I realise I need to do both courses. I drill straight through 1st brick , when do I stop drilling 2nd brick? half way or right through again?

how far apart are the holes to be drilled?

how much fluid into each hole?

all dumb questions I know but to the amateur...its a scary place to be!!!!!!

thanks for all advice given

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Joined: Sat Oct 19, 2013 11:26 pm

Postby welsh brickie » Wed Nov 27, 2013 8:02 am

drill wherever you deem nessasary, but drill 2, 10mm holes in 1 brick evenly spaced and drill on an angle facing down,
Also make sure you drill only halfway through the brick. You can hire the pump from your local hire centre, it comes with 6 nozzles, Insert the nozzle and tighten in place, the fluid will bubble out of the brick, so stop when that happens, then spray the front of the brick lightly, job done
for a solid double brick wall you really need to do each side, the fluid you use is up to you, they are basically all the same, your local hire centre sells the fluid, well it used to where I live
welsh brickie
Posts: 2160
Joined: Sat Apr 12, 2008 7:54 am

Postby TheDoctor4 » Wed Nov 27, 2013 9:30 am


You might find our Damp Proof Injection project helpful also

Kind Regards

The Doc
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Joined: Tue Jul 24, 2007 9:12 am
Location: Somerset in the UK in Shepton mallet

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