Standing Water and Lead

[gibboxxx]

Hi,

Can anyone tell me if standing water is a problem for lead? We have a poorly designed roof which causes a puddle to form on some lead flashing between main house and extension (not enough pitch to allow water to flow away freely). This has resulted in water penetration due to what our roofer says is poor lead work. He is going to rectify the lead work to make it water tight and has said that standing water is not a problem for lead if flashed probably. Can anyone advise if this is the case from experience?

Thanks.

 

[SurreyRoofingEstimator]

A picture would be good if you have one but water should not be sitting on a lead flashing at all. The water will find a way through the lap and happily drip inside if it is.

 

[gibboxxx]

Hi,

Thanks for the note. I can understand that if you are relying on sealant to make the lead joints this would degrade over time if submerged in water for any length of time. However, if the lead was soldered or leadwelded would this be a different matter?

Thanks

 

[masona]

However, if the lead was soldered or leadwelded would this be a different matter?

Thanks

Depends on the length with expansion, ideally best to modify the lead correctly if poss for long term

 

[^woody^]

I can't picture standing water on narrow lead flashing

If this is a flat roof, then the covering is the main part and any flashing just protection for the upstands. If this is the case then your probelm is with the flat roof covering and will not be solved by altering the flashing

 

[Nige F]

Hi,

Can anyone tell me if standing water is a problem for lead? We have a poorly designed roof which causes a puddle to form on some lead flashing between main house and extension (not enough pitch to allow water to flow away freely). This has resulted in water penetration due to what our roofer says is poor lead work. He is going to rectify the lead work to make it water tight and has said that standing water is not a problem for lead if flashed probably. Can anyone advise if this is the case from experience?

Thanks.

Kent ....Roofer... Leadwork ... I`m cynical but I smell Traveller Or maybe I`m gutted that roofers have pinched the leadwork from us plumbers

 

[gibboxxx]

Hi Woody,

Thanks for the note. I should explain. This is the valley between the tiles (pitch roof of the extension) and the main house wall. A valley of lead has been laid which causes some water to back up instead of draining out to the guttering and causes a puddle of water at the back where the lead is foldered. The roofer has re-laid the lead but without removing the whole roof and starting again we are stuck. I'm just trying to understand if lead will stand up to standing water if laid probably or if we can expect water pentration again at some point...

Thanks again

 

[SurreyRoofingEstimator]

Thanks.

Kent ....Roofer... Leadwork ... I`m cynical but I smell Traveller Or maybe I`m gutted that roofers have pinched the leadwork from us plumbers

lol, we'd rather plumbers would still do most leadwork TBH (saves us the pain of price increases every other day), main contractors don't want more than one trade on the roof nowadays, (remembers the good old days of `fix only soakers and pipe slates') only one person to blame if water gets in then , bit like builders doing roofing eh

 

[masona]

gibboxxx, can you take a photo?

 

[SASroofer]

Sounds like the valley gutter has been pitched the wrong way.

 

[^woody^]

So this is a secret gutter next to a wall?

If this is tiled then this must be virtually flat if no water drains down this gutter, but it surely can't be that low a pitch if this is a tiled roof?

Anything above 5 degrees would give a good steady flow, so again it's difficult to visualise a situation where this arrangement would hold water. Perhaps a bit of a hollow over any/each lath, but even so it should not be much water which can be held, and if this is the case then it wont be an issue

But you may be referring to the bottom bit at the eaves where a slight change of pitch occurs? If this is the case, then you need to pack the lead up slightly with a timber fillet or bit of ply. But again, there should not be much water here to cause a problem. However what may occur in this situation is water overflowing the side of the lead as it fills - so make sure the edges are turned up