Guttering drop measurement
Author
Discussion

fourstardan

Original Poster:

6,121 posts

165 months

Thursday 21st August 2025
quotequote all
Hiya,

doing 8 meters tomorrow and planning the job.

Run of 8500mm / 350 = 24mm

Does this mean the highest end needs to be 24mm below the end of the run?


CoolHands

21,981 posts

216 months

Thursday 21st August 2025
quotequote all
Yes, assuming you’re using the 1:350 gradient as the required drop which after a quick search seems correct. 3mm per metre.

J6542

3,083 posts

65 months

Thursday 21st August 2025
quotequote all
If you’re using deep flow gutters then 10mm will be fine. You don’t want the gutter to be to far below the tiles.

fourstardan

Original Poster:

6,121 posts

165 months

Thursday 21st August 2025
quotequote all
It's floplast.

I'm really umming and arring about whether to do eaves protector and lift the tiles.


RATATTAK

17,141 posts

210 months

Thursday 21st August 2025
quotequote all
fourstardan said:
Does this mean the highest end needs to be 24mm below the end of the run?
No, the highest end needs to be 24mm above the end of the run.

chris1roll

1,866 posts

265 months

Thursday 21st August 2025
quotequote all
Tio I learned a while back - Tape a 3mm spacer to the end of a 1m spirit level, there's your drop.

fourstardan

Original Poster:

6,121 posts

165 months

Friday 22nd August 2025
quotequote all
RATATTAK said:
No, the highest end needs to be 24mm above the end of the run.
Yes, you win a prize for the hidden mistake, where do I send the old guttering too lol

fourstardan

Original Poster:

6,121 posts

165 months

Tuesday 26th August 2025
quotequote all
Well the jobs done....

Not sure the gutters are bang on slope wise as I've got about 2mm of pooling in some spots. Builder mate says I am probably worrying about nothing.

I've got brackets every 75CM so will see how the rain goes over the next few days.