Bridging or rising damp?

[Danny]

If rising damp does not exist why do we install DPC's above ground level?

when water falls (ie off a soffit) when it hits the ground it splashes and normally it never splashes higher than 100mm...

thats my understanding for DPC

 

[Brimstone]

Right. So I’ve taken the cement/plaster off the chimney breast.

There was a back boiler in the space, which has been removed.
I’ve taken a brick out to the left and right of where the boiler used to be to add ventilation to the entire chimney.
I have also taken out some bricks at the front of the chimney (floor level) as there is a load of crap each side, which I intend to clean out to avoid any further issues and also aid ventilation.
As mentioned this is going to be a kitchen so I will box off main opening and install vents to maintain circulation.
They will be hidden behind the kitchen carcasses anyway.

How should I finish the chimney breast, sand/cement?
I’ve never used lime before but thinking that might be better.

View attachment 65677View attachment 65678

? Where you've broken out the inner skin of brickwork it looks like there is no cavity & the external skin is black from a fire, and would only be a half-brick thick to the outside. Not that unusual for the period but what about the rest of the huge wall? - check using the external brickwork bond pattern if there are two skins and actually are connected, don't think they used brick ties in the 1920's (?).

 

[Brimstone]

when water falls (ie off a soffit) when it hits the ground it splashes and normally it never splashes higher than 100mm...

thats my understanding for DPC

Yes, that's the main reason for it's height, and/or possible debris build-up, but if rising damp does not happen why bother with a DPC. If you refer back to your copy of Vetruvius book 7 on stucco ;-

The Romans, being excellent engineers, that have built some masterpieces that lasted over 2000 years. Historic records show that they not only were aware of the rising damp phenomenon, but they also worked out efficient solutions in combating it.

Roman architect and engineer Vitruvius in his famous Ten Books on Architecture has described the type of plaster mix that should be used on the lower parts of the walls subject to ground moisture:
https://www.coreconservation.co.uk/...-have-been-invented-by-the-chemical-industry/ - complete with a picture of a Roman slate stepped DPC.

Vetruvius book 7 on stucco and wall finishes is actually an interesting read !! (get the downloaded english translation, went to a concert sung in latin last night, didn't understand a word but the missus did).

 

[Dollar]