Vertical DPC on stone walls

[m7ohn]

Building an extension and tying in the new cavity wall to the existing stone wall.The stone wall now becomes an internal wall and i know that if it was a cavity wall then a vertical DPC would be inserted right through the exterior leaf of the old wall at the point between where the two new leafs tie in.
How is a vertical DPC achieved in a solid stone wall?i.e no cavity.

[dcmoore]

Take a look at any one of our damp projects and ring the phone number for Property Repair Systems. They give free, no obligation advice and we recommend them. They will tell you what you need to do (if anything) and will also be able to supply you with anything you need to do it with but will certainly not try to sell you anything you don't need