What size flashing to use?

[marsaday]

I am going to redo my lead flashing on my chimney - soakers and the flashing i think.

The chimney is positioned in the middle of the roof, astride the ridge.

From the ridge to the bottom of the chimney is 1.05m. So i have 2 of these lengths and need to make enough for soakers and chimney. So i thought a roll of 6m would be enough.

What about the width of the flashing. Is this governed by the bricks or tile size ?

I was thinking 9" may be fine.

How do a size it correctly ?

 

[palaceray]

I assume you have 10.5 x 6,5 plain tiles. You should use a roll of 180mm code 4 lead. The soakers should be 190mm long and be bent with a 75mm upstand. The 180 is spot on for step flashing as well.

 

[catlad]

9" will do as most places will not stock a 7" roll of lead.

 

[marsaday]

We have slate, not tile - sorry.

 

[palaceray]

in that case the length of the soakers will be different but still 180mm lead for soakers and flashing.

 

[yorkie1969]

You will need code 3 lead for the soakers so that the slates sit correctly.
To work out how much soaker lead you need you times the distance needed to be covered by 1.5, therefore you may just have enough with a 3 metre roll of 180 wide lead.
With regards to the step flashings you need a 3 metre roll of 180 wide code 4 lead.
You will need a 75mm waterline and be sure to turn the lead at least 25mm into the joint.
The videos below are most informative.

http://www.youtube.com/watch?v=hkvwjE0LQOM
http://www.youtube.com/watch?v=xeDPfKDG8u8

Good luck.