Installing a lead flashing - hints and tips needed! (pics)

[spooky_b329]

I have a lean to kitchen/bathroom that is back to back with the neighbours. There is no lead flashing along the top of the roof, and water is starting to drip in when it rains. It may be after the tiles were disturbed to fit the windows, or the old plaster and lathe ceiling (now removed) was soaking up the drips so it wasn't noticeable.

Pics below:

The plan:

Angle grind a 2" deep slit the length of the roof (approx 6 metres) insert lead flashing, and pack with mortar. How high should the slit be above the tiles? Am I likely to be able to get a roll of lead long enough for the whole lot or will I need overlaps...how big should these overlaps be? And how far does the lead need to cover the tiles?

The top of the wall is also in a sorry condition, what would be the best solution for this? Strip off the old gunk and install coping stones along the top?

Thanks for any pointers...anything I'm missing or should do differently?

One last thing...where should I go to buy lead, and what sort of price would I be looking at?

Thanks,
Ollie (Brighton/Eastbourne area)

 

[GaryinAshby]

If you're going to put coping stones on the top, why not just trap the lead underneath rather than cutting a slot? You could also do next doors at the same time (for a price!).

 

[spooky_b329]

Thanks Gary.

This did cross my mind but I wasn't sure if it was doable as the wall rises about 250-300mm above the tiles...could the lead lift in the wind or is there some way of securing it to the face of the wall?

 

[spooky_b329]

Just been out and had a closer look, the neighbour already has a flashing, and if you take a closer look at the 1st pic, the line on the second half of the lean-to is next doors flashing, it passes under the concrete ridge and comes out our side about 20mm.

 

[datarebal]

You could take a bit of the brickwork down, then simply bed a ridge tile along .. You would need to use an angle hip as these are available quite wide..

Flashing is fine but in this case only totally reliable if there is a tray fitted..
Flashing lengths should not exceed 1.5mtr (code4) overlaps =150mm any flashing fitted in a chase should be wedged before pointing.

 

[spooky_b329]

When you say tray do you mean a cavity tray?

The wall is solid 9".

 

[noseall]

that is an odd looking roof!

why would you take a parapet up through the ridge?

i guess to 'separate' the properties and define their boundaries.

enclosing the area with lead and copings makes the most sense. it would have been more sensible however to have kept the masonry below the roof line and fitted a ridge.

 

[datarebal]

yes it's a solid wall, that still needs a tray... it does not have to be cavity or water to soak through brick work

 

[spooky_b329]

All the extensions were built at different times, I think the order in this case was:

My first half (the kitchen), then next door built their whole extension, then our bathroom was tacked on the end. Suppose the parapet wall was the thing to do when there was no building the other side? The whole road has extensions built in this way, though all different widths and lengths, including one two story painted blockwork monstrosity with a flat roof.

Anyway, currently the best option is this?

Someone suggested I could using something similar to roofing felt that you heat with a 3 burner blow torch as it would be cheaper than lead? This would go over the parapet and remove the need for coping stones as well. Thoughts?

 

[noseall]

torched on felt is likely to split at the roof tile- wall abutment, due to the fact it will be stuck down and not allowed to move with the roof. too rigid.

use lead. this can be dressed down onto the tiles and not glued. it will move with the roof.

 

[spooky_b329]

Sorted Got someone in to do it in the end.

Thanks for your help everyone.

 

[Roofer]

I'm VERY impressed that on Tuesday at 4 pm you had a problem and by Friday 2 pm it's all sorted and looks an ok job as well.

Is this a wind-up?

 

[spooky_b329]

Nope, its great isn't it

I've got a load of leave to use up from work otherwise I lose it. Had to get windows fitted, floor and ceiling boarded, floor levelled, electrics done and then fit kitchen, tiling etc.

Spent a week faffing around trying to get windows sorted then these guys blocked me in doing a neighbour. Asked them to quote for the windows, they said yep we can do 'em tomorrow as we have nothing planned!

Got them fitted, next weekend I plasterboarded, waiting for the storm before finishing, found drips, faffed for a couple of days deciding if I should do it myself, gave up, called them again, they came round next lunchtime to look, then said Fridays job was cancelled (or they delayed it/couldn't do it as not forecast to be dry) so they came round it did it this morning

Well impressed...back to the DIY now...and its just started raining so fingers crossed...

(being a storm on Monday I assumed that everyone would be busy and really expensive!)

PS: relieved that you think it looks OK as well...they are flat roofing specialists so both jobs they did for me were both out of the norm for them...think the windows gave them a few headaches

 

[datarebal]

torch on! jesus..