i've just completed the slate roof on the extention to our house and am now ready to do the flashing.The problem is the house is pebblesdashed, can i cut a groove parralel to the roof line in the pebbledash then another between that and the roof line to push the lead flashing into that rather than chasing out the mortar as this will require more pebbledash removal. Or alternatively can i use a stick on type flashing? that way i could still have a neat line between the roof and pebbledash. My architects plans say to use code 4 lead but i'm sure there are alternatives out there that are not desirable to undesirables
If you are going to use lead then it doesn't matter how you tuck the lead into the wall provided it goes in by about 25mm so angle grinding a groove will be OK.
Sticking flashing on the surface is not good because water can still get down the back of the flashing.
Thanks for the info but I was trying not to use lead. Can I use a lead substitute that has no scrap value? How far up the wall do I need to go and how far across the tiles do I need to go if using a substitute? Thanks again, Rod
If rain is driven against the wall above the flashing if it is a stick-on product rain water will penetrate the roof space - getting a good seal onto pebbledash is almost impossible.
How far you need to go down the roof will depend on whether a double row of tiles has been fitted on the top edge (if its conventional plain tiles) or about 100mm should be enough if its interlocking tiles.
You could try a mortared fillet along the join between the roof and the wall but this needs to be bonded onto the wall and once the fillet is dry the wall and fillet waterproofed.