Flashing & Soakers

[diggerpaul]

Hi, I have decided to roof my extension myself. I am using fibre cement slates. Where the pitched roof abutts the main house I am going to do some stepped flashing. My local roofing supplier can only offer me aluminium soakers that are 300mm long, and in fact he says that they only sell 300mm ones. Sources on the internet tell me that they should be 400mm long for 600mm long slates. My gauge is 250mm. If I use the 300mm long soakers, then their effective lap will be only 50mm. I am worried about this.
Any ideas ?

 

[palaceray]

You should buy 180mm code 3 lead and cut and form ypour owm soakers with a 75mm upstand. Your step flashing should be done with 180mm code 4 with a 75mm water line.

 

[diggerpaul]

Thanks for the reply. I agree that maybe forming my own soakers will be the answer. However, I am surprised that you talk about 180mm lead. This has long been an imperial product and ALL the local suppliers offer it in 6", 9" or 12". We have not seen 180mm lead. Where do you get yours ?

Paul

 

[Nige F]

I`ve got 6 inches - but I don`t use it as a rule

 

[palaceray]

all roofing supplies i know now sell metric sizes, if not 6 inch would be ok with a 2 inch upstand. BS now is 180mm

 

[diggerpaul]

OK, I will challenge them on that. What length should my soakers be and should they be flush at the top of the slate ?

Paul

 

[noseall]

180mm wide lead?

 

[Roofer]

180mm wide lead?

Absolutely correct - Code 3 180mm for Slates and Plain tiles

http://www.leadsheetassociation.org.uk/soakers-and-step-flashings

 

[noseall]

For the entire time that i have been in the trade, i have never seen anyone else use or have never used myself anything other than 150mm x 150mm lead soakers for plain clay tiles.

Eaves course excluded due to it being more elongated of course.

These would be typically bent down the middle with an additional nib added for a left or right-hand soaker.

Also, the only soakers i have ever removed form a plain tile roof (old or recent) have all been formed from 150mm (6") lead.

I have never seen one leak as a result of soaker failure.

Where can you buy 180mm lead off the shelf in any case?

 

[Roofer]

I agree that 6" (150mm) soakers were solely used for many, many years.

But 7" (180mm) have been used for probably the last 10 years.

Not saying they are any better but that is what is now specified by LDA, NHBC and in NBS specs.

The lead is always available in Roofing Merchants

 

[palaceray]

The soakers for your slates should be 375mm long nd nail into the batten on top of each slate course.

It is available from Asphaltics or roofshop and should be available at any good roofing suppliers.

 

[noseall]

Not saying they are any better but that is what is now specified by LDA, NHBC and in NBS specs.

Gotcha. I only ever do private work so I am out of the loop as it were.

The lead is always available in Roofing Merchants

There's me thinking you could only get 6", 9", 12", 18" etc.

Must try harder.

 

[diggerpaul]

Hey guys, thanks for all your help. Just one last thing. If I use soakers, does that mean that my stepped flashing need only be vertical on the brickwork and not fold horizontally over the slates ?

Paul

 

[diggerpaul]

The soakers for your slates should be 375mm long nd nail into the batten on top of each slate course.

It is available from Asphaltics or roofshop and should be available at any good roofing suppliers.

Just rang local Asphaltic and indeed a local Roofshop and they only stock 300mm soakers !!

 

[diggerpaul]

Can anyone specify an actual online supplier who has 350mm or 375mm preformed aluminium soakers ?