Regs for flat lead roofs

[a1topdog]

I am in the middle of having a new flat roof covered in lead. The area of the roof is approx 4m sq.

I was expecting the fall to be gradual from one side of the roof to the other , but the lead roofer has put a 2" + step in the middle of the roof and it looks awful.

When I questioned it he said it has to be done like that - something to do with weather proofing and the max size of the lead sheets allowed for expansion etc.

Is this right?

 

[chappers]

is it atcually a 2" step or is it a two inch hump running the length of the fall of the roof?

 

[a1topdog]

It is an actual step.

The roof fall is from right to left. Approx half way the roof steps down.

The "hump" I think you are referring to are there as well. Rounded wooden battens have been nailed to the roof before the lead was laid. They run the same way as the fall , I would say approx 1m apart. But is not these that I am worried about.

 

[kevplumb]

double welted joints i take it

 

[a1topdog]

I'm not sure what the joints are - All I can tell you the corners are neatly welded!!

The scaffolding is down now so I can't check. I don't doubt the quality of the roofers work , I just don't like the blasted step

Just to make it clear the roof is vitually horizontal , not a steep sloping flat roof - if that make sense.

The flat roof is at the top of a pitched one. It actually is proud of the pitched roof , not sitting below it. My builder it trying to find away to hide the proud edges. I think he is going to try a run of ridge tiles , but I have no idea how he plans to make them stick to the lead.

 

[kevplumb]

cant understand why you need a 2"" drop in the roof the rolls are standard practice to allow for expansion
lead creeps

still dont explain your gripe


FWIW
i think you have a point
and somebody is feeding you cr*p

 

[a1topdog]

Right - I've spoken to http://www.leadsheetassociation.org.uk/ and what the roofer had done is correct.

If the roof is below 11 deg pitch (mine is) a 50mm or 55mm step has to be put in. The distance it has to be put in depends on the code of lead used.

My roofer is using code 6 lead to the max lenght of the lead can be 2.25m.

If the roof had 11 deg or greater pitch a lap joint could have been used.

Looks like I'm stuck with it.

 

[kevplumb]

such is life