Hi
We have a 'sun room' which was built with cavity walls. It has a polycarbonate roof and the top of the walls is finished with coping stones. I need to replace the roof and noticed that the mortar joints between the coping stones have flashing band over them. Is this necessary to keep things watertight? If it is, would it be appropriate to use wide lead flashing to cover the gap at the top between the inner and outer brick course going down to the roofing sheets. If I do this will the coping stones 'stick' to the flashing with mortar bearing in mind that they will effectively not contact the brickwork below them, only the flashing. Sorry to ask so many questions!
Malcolm
We have a 'sun room' which was built with cavity walls. It has a polycarbonate roof and the top of the walls is finished with coping stones. I need to replace the roof and noticed that the mortar joints between the coping stones have flashing band over them. Is this necessary to keep things watertight? If it is, would it be appropriate to use wide lead flashing to cover the gap at the top between the inner and outer brick course going down to the roofing sheets. If I do this will the coping stones 'stick' to the flashing with mortar bearing in mind that they will effectively not contact the brickwork below them, only the flashing. Sorry to ask so many questions!
Malcolm
mortar will stick to lead but it should be coated with bitumen paint first - then 99.9% of jobs it isn`t 
