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 𝟐
Solution
A
B
Area of Roof B
8m x 20m = 160 m 𝟐

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
𝐃 = 𝟏𝟎𝟎𝐦𝐦
 Cross section: A1 = πD2
/4 = 3.14 × 1002
/4 = 7850𝑚m2
Divide into two terminals: 3925𝑚𝑚2
Chooses D = 75mm ; A2 = π ×
752
4
= 4416𝑚m2
> 3925mm2
D = 75mm OK ! 
D = 50mm, A = 1963𝑚m2
< 3925𝑚𝑚2

D = 90mm, A = 6359mm2
> 3925𝑚𝑚2
(Not economic)
𝐃 = 𝟗𝟎𝐦𝐦
 Cross section: A1 = πD2
/4 = 3.14 × 902
/4 = 6359𝑚m2
Divide into two terminals: 3179𝑚𝑚2
Chooses D = 75mm ; A2 = π × 752
/4 = 4415𝑚m2
> 3179𝑚𝑚2
D = 75mm OK ! 

9. Second Solution
Roof A
𝐴 = 200𝑚2
2 terminals = 100𝑚2
Roof B
𝐴 = 160𝑚2
2 terminals = 80𝑚2
Choose 𝐷 = 75𝑚𝑚
Thank You !!!