8.4 roof leader

Sanitary installation

1. In plumbing, a pipe installed to drain water
from the roof gutters or roof catchment to the
storm drain or other means of disposal. Also
called a conductor, downspout, or roof drain.
8.4 Roof Leader

2. Roof gutter

3. Downspout
Roof Drain

4. Roof leader is either Exposed or Concealed Type

Pit
Drain Pipe

5. Illustration

6. Area of Roof A
10m x 20m = 200 m
�


Solution
A
B
Area of Roof B
8m x 20m = 160 m
�

7. Comments
 For 20 meters length of the gutter the rains has to
travel a long way, It might be overloaded and overflow.
The terminal maybe clogged with dirty such as leaves,
etc. Thus, We need two or more terminals for roof
leader.
D=100mm & D=90mm
( expensive or oversized ):

8. Find the number of terminals
??????=���????????????
Cross section: A
1=πD
2
/4=3.14×100
2
/4=7850??????m
2

Divide into two terminals: 3925????????????
2

Chooses D=75mm ; A
2=π×
75
2
4
=4416??????m
2
>3925mm
2

D=75mm OK ! 
D=50mm,A=1963??????m
2
<3925????????????
2

D=90mm,A=6359mm
2
>3925????????????
2
(Not economic)

??????=??????&#3627409358;????????????
Cross section: A
1=πD
2
/4=3.14×90
2
/4=6359??????m
2

Divide into two terminals: 3179????????????
2

Chooses D=75mm ; A
2=π×75
2
/4=4415??????m
2
>3179????????????
2

D=75mm OK ! 

9. Second Solution
Roof A
??????=200??????
2

2 terminals =100??????
2

Roof B
??????=160??????
2

2 terminals =80??????
2


Choose ??????=75????????????
Thank You !!!