dpc breached

[mijabobl]

hi there I have 1930s bungalow with dpc breached all round with Tarmac path ways and drives about 200 mm above dpc, one corner is really bad, timber damages etc,

company wants 2 grand to put in new dpc and hack off plaster and re floor defected areas

pretty ok with this, but is it still necessary to lower ground outside?

they are clearing cavity and raking out to 100 mm below dpc and with this they say it won't need lowering as it won't get across to inner wall

is this ok?

 

[gregers]

if they are clearing cavities,then no the outside will not need lowering.
but ask yourself this question.if the cavities are full DO you have a rising damp problem or a penetrating one?

im also thinking that once cavities are clear and time allowance for the walls to dry out,will you still have a damp problem.

are they exposing the cavity from inside or out,if inside then i suspect they have also suggested re plastering the interior walls?

agsin if they attack the problem from outside,and the walls dry out over time,then this will not require the walls to be hacked off and re plastered.

 

[tony1851]

if they are clearing cavities,then no the outside will not need lowering.

If that was the case, then logically we wouldn't need to incorporate dpcs in the external skin?
But the outer dpc is also intended to protect the brickwork from frost- and sulphate attack etc.
IMO the ground should still be lowered.

 

[mijabobl]

thanks for reply

very good info, the walls have high moisture content, about 28 percent in areas, but they say dpc could be in affective so just as well inject a dpc in case and hack off plaster,

they will be doing it from outside so you are right, may not be worth re plastering, but is it worth it for the interior dpc?

 

[gregers]

well to install the dpc,they will have to do this from the inside,hence the removal of plaster.and then as it is off they will form the holes to gain access to the cavities for clearing.

now this is the crux if they formed holes on the outside and cleared the cavities,as i said in my post would there still be damp?