I presume you're having an injection dpc installed. This is a system that relies on two parts. The first part, i.e. the injection, controls but does not cure the rising dampness. The second part, i.e. the re-plastering, does two things. Firstly it prohibits the migration to the surface of any ground salts that are in the wall. These salts are hygroscopic and, if they get to the surface, will absorb moisture from the atmosphere. The second thing it does is to inhibit moisture within the masonry from reaching the surface too.
The two things work in tandem.
If you're going to dry-line the walls, then there's probably little point in injecting in the first place. If you do the dry-lining correctly then the dampness, if there actually is any that isn't the result of condensation, can stay in the wall until Kingdom Come without doing any harm.
If your walls are suffering from condensation, as are most of the ones that I see, then the dpc won't have any effect at all and in seven years when you come to sell and the building surveyor finds 'dampness in the lower reaches of the walls', your contractor, if he's still around, will come back and say 'Oh well Guv, that's condensation"
Asking if it's condensation now, why wasn't it condensation then?, won't get you anywhere, The water will be well and truly under the bridge!
Have a look at my website
www.pdoyle.net for further info and to see what you're letting yourself in for
HTH
Patrick
