Maximum Trench Widths
| ||
---|---|---|
Nominal Pipe Diameter
(inches)
|
Aggregate Backfill Width
(inches)
| |
4
|
24
| |
6
|
24
| |
8
|
24
| |
10
|
28
| |
12
|
30
| |
14
|
32
| |
15
|
33
| |
16
|
34
| |
18
|
36
| |
20
|
40
| |
21
|
42
| |
24
|
48
| |
27
|
54
| |
30
|
60
| |
33
|
63
| |
36
|
66
| |
42
|
75
| |
48
|
84
| |
54
|
90
| |
60
|
96
| |
66
|
106
|
Pipe Size
(inches)
|
Length
(feet)
| |
---|---|---|
6 and 8
|
5
| |
10 to 16
|
5
| |
18 or larger
|
8
|