Lead flashing under dormer windows

[andyc11]

Nearing the end of a full re-roof and following getting the dormer rendered, noticed the lead flashing hadn’t been replaced (despite asking for this and the quote including it). As the render was completed and the roofer was nervous about damaging it, they cut out the old and have simply screwed the new under the window sill. Wouldn’t have thought this was the best way of doing the job, but appreciate any thoughts.

[Pflanzgarten]

Is that small upstand where it finishes?

[andyc11]

3 windows run along the dormer, flashing has been replaced on the sides before the render. The second picture above shows the old flashing, which was fitted under the sill. They’ve said that they’ve cut out the old leaving part of it fitted under the sill and then installed new flashing on top. Had a lot of leaks hence the reroof, so not sure if I’m just being paranoid.

Edited by andyc11 on Thursday 18th August 07:50

[Aluminati]

It’s very shoddy. To replace properly the window should be out. Looks like you have a decent bell drip on the render, but lead should have gone on first.

Biggest issue is the gutter they have created at the top of the tile, this will fill with water, which will run under the lap. Its amongst the worst fitted lead I have seen in 40 years in the industry.

Tile overhang on the dormer should be 50 mm also. Looks short ?

[Pflanzgarten]

£50 says they're relying on silicone and hope to stop it leaking due to wind pressure on the front elevation.

[andyc11]

Aluminati said:

It’s very shoddy. To replace properly the window should be out. Looks like you have a decent bell drip on the render, but lead should have gone on first.

Biggest issue is the gutter they have created at the top of the tile, this will fill with water, which will run under the lap. Its amongst the worst fitted lead I have seen in 40 years in the industry.

Tile overhang on the dormer should be 50 mm also. Looks short ?

Help me out with your second paragraph please. Is this the smaller section of the roof under the dormer windows?

[Pflanzgarten]

andyc11 said:

Help me out with your second paragraph please. Is this the smaller section of the roof under the dormer windows?

Your first photo shows what appears to be a hollow with no tiles support underneath, so the water will pool in it. If the win blows towards the front of the house this will naturally drive up and beyond the makeshift upstand.

That upstand by the way, should be a minimum of 150mm and covered with a flashing above if installed the way it is. Looks about 80mm if being generous.

[OutInTheShed]

Aluminati said:

It’s very shoddy. To replace properly the window should be out. Looks like you have a decent bell drip on the render, but lead should have gone on first.

Biggest issue is the gutter they have created at the top of the tile, this will fill with water, which will run under the lap. Its amongst the worst fitted lead I have seen in 40 years in the industry.

Tile overhang on the dormer should be 50 mm also. Looks short ?

Tiles should not be sat on the wood bit like that surely? (middle pic)

Get a surveyor in to tell them to do it all again, or throw them off site and get someone competent.

[Aluminati]

andyc11 said:

Help me out with your second paragraph please. Is this the smaller section of the roof under the dormer windows?

Where they have dressed the lead over the tiles, you can see they have created a flat spot/trough. So instead of the water running down the tile, it will collect in the trough, and run under the lap where the join in the lead is.

[Aluminati]

Pflanzgarten said:

That upstand by the way, should be a minimum of 150mm and covered with a flashing above if installed the way it is. Looks about 80mm if being generous.

150 mm would not be required in this instance. Regs on a flat roof terrace now only require 75mm where patio doors are installed for instance, as long as the membranes are turned up and onto the opening before the doors/window are fitted and sealed appropriately.

[Pflanzgarten]

Aluminati said:

Pflanzgarten said:

That upstand by the way, should be a minimum of 150mm and covered with a flashing above if installed the way it is. Looks about 80mm if being generous.

150 mm would not be required in this instance. Regs on a flat roof terrace now only require 75mm where patio doors are installed for instance, as long as the membranes are turned up and onto the opening before the doors/window are fitted and sealed appropriately.

Interesting, I wasn’t aware that was the case where the upstand is covered by a flashing.

[andyc11]

Thanks for the replies here. I’ll jump up on the scaffolding and get some better pictures, not to say the feedback here isn’t accurate, just that leaning out of the window isn’t always the best way of showing work completed.

[Aluminati]

OutInTheShed said:

Tiles should not be sat on the wood bit like that surely? (middle pic)

Get a surveyor in to tell them to do it all again, or throw them off site and get someone competent.

I’m assuming there’s a fascia going on, but see no eave tray or 5U fitted for drape into gutter.

[Aluminati]

andyc11 said:

Thanks for the replies here. I’ll jump up on the scaffolding and get some better pictures, not to say the feedback here isn’t accurate, just that leaning out of the window isn’t always the best way of showing work completed.

Crude edit, but…

[Aluminati]

Pflanzgarten said:

Interesting, I wasn’t aware that was the case where the upstand is covered by a flashing.

Technically, they haven’t covered an upstand with a flashing, they’ve done it in one piece. The tile cover should turn up the window abutment, then have a seperate cover flashing yes. They also haven’t installed any check straps to stop the lead slipping down the tile, which at that size and weight, it will do, without the wind lift element.

That lead wasn’t fitted by anyone remotely competent.

[Aluminati]

On a mission now,

If this is a vertical meeting a pitch, as it looks, if he is intending to tile it like it looks, chuck them off site.

[OutInTheShed]

Aluminati said:

OutInTheShed said:

Tiles should not be sat on the wood bit like that surely? (middle pic)

Get a surveyor in to tell them to do it all again, or throw them off site and get someone competent.

I’m assuming there’s a fascia going on, but see no eave tray or 5U fitted for drape into gutter.

Possibly what I thought was the top surface of the bit of wood, is in fact beige coloured membrane?
Is that stuff good for years of sunlight?

[Pflanzgarten]

Aluminati said:

Pflanzgarten said:

Interesting, I wasn’t aware that was the case where the upstand is covered by a flashing.

Technically, they haven’t covered an upstand with a flashing, they’ve done it in one piece. The tile cover should turn up the window abutment, then have a seperate cover flashing yes. They also haven’t installed any check straps to stop the lead slipping down the tile, which at that size and weight, it will do, without the wind lift element.

That lead wasn’t fitted by anyone remotely competent.

Yes, I get what you mean about the lack of cover flashing and I know it isn’t there on this example. I can’t believe they didn’t use the existing lead for this cover before cutting it off?

Still 75mm is handy to know-I’ve still been working off 150mm (not that I do loads of lead work these days)!

We had a recurring problem on my parents dorma that took about 30 years of faffing to figure out-the bugger only leaked about once every 5-10 years when a particularly bad storm blew in from a funny direction.

Regardless, the OP needs to be asking some serious questions about what’s going on here if it appears as in the pictures.

[andyc11]

[Pflanzgarten]

What’s the plural for lots of different roofs, a riot of roofing?