Q:
How critical is the use of a drain pipe for a 3 ft (0.91 m) high wall? I understand that the blocks are designed to weep water that is behind them. Isn’t using stone behind the wall sufficient?
A:
For a typical 3 ft (0.91 m) retaining wall, which has not already been designed by a local engineer, you may be able to get away with not adding the drain pipe. Per page 14 of our AB Landscape Walls Guide, I would recommend a drain pipe whenever one of these cases exists on your jobsite:
- Walls taller than 4 ft (1.2 m)
- Sites with poorly draining soils (particularly clays)
- Alongside paved areas
- When there are slopes above the walls
- In a terraced wall application
- On all municipal and commercial projects
Proper water management is critical to the life of a segmental retaining wall. The rock behind the wall is only intended for relieving incidental water. It is important to grade the site as to divert water away from the wall.
To access the AB Walls Landscape Wall Guide click the Product Literaturelink under the Home Owners tab on the allanblock.com home page.
Allan Block Literature
