We've got a roof terrace above the kitchen (properly built load-bearing job) and it's finished in paving slabs - which wasn't really what we asked for but the builder did it while I wasn't looking. (Yes, I know; never turn your back on a builder 
but he'd done a good job up until then.)
A while back, I noticed that small amounts of water were coming down the kitchen wall during heavy rain. Up came a few slabs and there, right in the corner between roof and parapet wall, was a small split. Being in a hurry, I cleaned up the surfaces as best I could and applied a generous length of self adhesive flashing. Then I laid some old cardboard to protect the felt below and put the slabs back. This was temporary as I intend to remove all the slabs and tile it properly.
Everything was watertight, even after a generous hosing down, until last week. We had a seriously heavy downpour and got a puddle in the kitchen. When I looked at the flashing it had lost its grip on the vertical felt surface, allowing a small gap to open. The water must have risen high enough between slab and wall to flood over into this gap and, from there, into the kitchen.
Now I can see that I need a proper repair, presumably a decent sized piece of roofing felt, tied into the parapet wall like the existing stuff and spread out across the flat roof. Meanwhile, I need the quickest way to get this flashing - or a new bit of something - stuck back onto the wall.
Is there anything I can paint into the gap that will hold? Should I peel off the offending section to clean up and start again, maybe with some kind of primer this time? Should I use a different material altogether?
I've got some lead and I've used that on a different flat roof to form a proper seal around a soil pipe. In that case I used a hot air gun to melt the lead into the bitumen and it's never budged. I'm reluctant to try this with the flashing strip in case it all melts into a sticky mess, though I've considered softening the existing felt before sticking the flashing on. Any advice would be welcome.
Next question. I'm going to lift all the abominable slabs and clean up the felt as best I can ready to take much lighter tiles. What's the best way to fix these. Should they go on a mortar screed or be bedded in hot-poured bitumen, or something else I haven't even thought of?
but he'd done a good job up until then.)A while back, I noticed that small amounts of water were coming down the kitchen wall during heavy rain. Up came a few slabs and there, right in the corner between roof and parapet wall, was a small split. Being in a hurry, I cleaned up the surfaces as best I could and applied a generous length of self adhesive flashing. Then I laid some old cardboard to protect the felt below and put the slabs back. This was temporary as I intend to remove all the slabs and tile it properly.
Everything was watertight, even after a generous hosing down, until last week. We had a seriously heavy downpour and got a puddle in the kitchen.
When I looked at the flashing it had lost its grip on the vertical felt surface, allowing a small gap to open. The water must have risen high enough between slab and wall to flood over into this gap and, from there, into the kitchen.Now I can see that I need a proper repair, presumably a decent sized piece of roofing felt, tied into the parapet wall like the existing stuff and spread out across the flat roof. Meanwhile, I need the quickest way to get this flashing - or a new bit of something - stuck back onto the wall.
Is there anything I can paint into the gap that will hold? Should I peel off the offending section to clean up and start again, maybe with some kind of primer this time? Should I use a different material altogether?
I've got some lead and I've used that on a different flat roof to form a proper seal around a soil pipe. In that case I used a hot air gun to melt the lead into the bitumen and it's never budged. I'm reluctant to try this with the flashing strip in case it all melts into a sticky mess, though I've considered softening the existing felt before sticking the flashing on. Any advice would be welcome.
Next question. I'm going to lift all the abominable slabs and clean up the felt as best I can ready to take much lighter tiles. What's the best way to fix these. Should they go on a mortar screed or be bedded in hot-poured bitumen, or something else I haven't even thought of?
