Roofing and Guttering: tapered lead gutter

Hi, I'm in the process of building a small extension to a bungalow which requires a 3.5m tapered lead gutter. The 2 roof slopes are 17.5 degrees with an existing gable at the gutter head.

I have read the info' in Rolled Lead Sheet by the Lead Sheet Association and think I understand the basics (!). I have done some less complex leadwork (years ago) and intend to have a go at this myself.

My question is which one of the following approaches would be best
a) 3 bays (top 2 with rolls) of 1.2m approx in code 5 or,
b) 2 bays (top 1 with roll) of 1.8m approx in code 6
or is there a better way? Hope this makes sense.

Opinions gratefully received

Many thanks

Hi. If you make the sole of gutter 150mm at lowest end and apply min fall of 1:80 and a 55mm drip at 1850 mm back from discharge point, this will allow you to complete the work in code 5, you will however need a roll on the top bay, the most important thing to remember is to only fix/nail the lead at to head (top edge at highest points of bays) and that when tiles are fitted no fixings through lead. ( If over fixed, movement is restricted which over time will lead to fatigue and failure. Good luck

Hi. Thanks for the advice. I was a bit unsure about going close to the length limit on code 5 (2m ?), bit over cautious perhaps. Note your comments on fixing.

Incidentally I've seen your (well I think its you), excellent lead burning/working videos on YouTube. Very helpful.

Thanks again

(apologies to administrator for posting error: hope this is right)