sarahbee said:
I have just had a garage conversion done and after contacting the council for a regularisation
You obviously realise that Regularisation is a procedure to get your local authorities rubber stamp on illicit work. Were you aware, during the works, that your local BCO should have been involved? Sometimes these situations arise, due to the advice that cowboys give their clients. If this is the case you'd be best to get onto your local CAB office regarding how you may claim from the builders.
If the decision, not to seek planning permission was yours, then you've probably got a pretty poor case.
I can think of three methods to retrospectively insert the DPC. They are all pretty labour intensive.
1) Provide temporary support for the ceiling/roof (by means of acrows), remove the windows and wall, in it's entirety and rebuild (complete with a DPC).
2) Pass steel pins through the wall somewhere above the DPC. Place substantial timbers under these (inside and out) support these timbers. Remove brickwork below the supported area and rebuild.
3) Starting at one end, remove the brickwork from a small section of the wall. Put a roll of DPC into the wall at this section, with the loose end laid in place. Replace brickwork on top of the loose end, fill above it. remove some more brickwork beside the section you have just done, and unroll some more of the dpc. fill above this section. Continue this process until you have gone across the entire width of the wall.
The third method would probably cause the least disruption but, due to the history of the project, your BCO will probably want to have a clear view of the entire DPC sitting in place, before you cover it. This would be impractical with this method.
The other thing that occurs to me is that, it's always possible, during the inspection of your DPC, other indiscretions may come to light. (such as inadequate insulation or wall ties). So, in view of the negligent attitude of your builders, you'd probably be best off ripping the whole lot out and doing it again properly.