Chris Styles wrote:
Hi,

A friend is looking to buy a Victorian Terraced house, and it doesn't have a
damp course.

After spinning her an elaborate story about having the entire house sliced
out of the terrace and lifted up on blocks while a damp course is fitted, I
promised to ask around to find out how much she should expect to pay to have
a chemical DPC done.

I seem to recall someone else having the chemical DPC, and it requiring a
certain amount of replastering to be done after, because the plaster had to
be stripped back at the bottom of the wall. Is this normal (or even anything
to do with the DPC?)

Any hints, tips gratefully received.


Biggest problem is that while injecting outer walls is relatively easy,
inner walls are less so, and chimneys are damn near impossible.

Forget the arseholes who say that rising damp doesn't exist BTW, it damn
well does and it is a nightmare if you want to turn a draughty open
fired house into a cosy des res.

In general apart from DP injection, you have two or three other lines of
attack.

Firstly lowering the local water table: you create a gravel filled moat
round the property and drain it. Easy if on high or sloping ground,
requires pump and a sump if lower down.

Secondly waterproof tanking up the inside walls. This works by basically
making sure that as the damp travels upwards, it doesn't come inside
until its had a damn good chance to evaporate outwards. This works well
on single brick with no cavity but not well on cavity walls unless they
are airbricked and even then its not that hot. And of course is some
**** has decided your problem was penetrating damp, cos he listened to
some other ****, and has waterproofed the walls outside, you are in deep
**** anyway.

Finally. whatever is left, you control with heat and ventilation. Damp
per se is only a problem if it leads to blown plaster, mould or rotting
wood.





Chris