Roofer has caused damage to parts of a party parapet wall, by chasing out joints above and below the what I call the part of cavity tray that protrudes from wall drip tray, by using a small hand cutter.
The cavity trays are metal type welded together approx. 8m in total length.
As it is only parts of the tray that protrudes from wall. Would it be possible to chase out the joint below the protruding cavity wall plate approx 75mm in order to be able to slide the lead flashing under the damaged parts of the trays then fully filled chase with sealant. Or should retro trays be fitted.
