Replacing downspout extension on side sewer
Posted by Mark Gendron on November 30, 2001 at 20:34:11:
Well, the weekend's here and the Seattle sewer inspector never got back to me (I thought the permit included advice!) Can you answer any of these questions for me? I'd like to get this job done this weekend if I possibly can.


I am replacing a downspout drain to my side sewer, and I have a few questions:

1. What diameter pipe should be used for downspout drains? (4", I believe).

2. What type of pipe is required? Schedule 40 PVC? This will be in the yard--no vehicle traffic over it.

3. What type of connector is approved for connecting the new pipe to the existing drain tile? I assume it'll be neoprene. . .does it need a metal sleeve over the outside?

4. How much pea gravel is required? (depth below pipe, depth above pipe, amount of gravel on each side of pipe)

5. Do I need to install a cleanout and/or test tee where the new pipe connects to the existing drain tile? Total run of new pipe will be about 18'.

6. Should I install a catchbasin or any other type of trap where the downspout enters the pipe?

7. The existing drain tile is 3" ID. If the new pipe is to be 4", is it OK to connect it to the existing 3" tiles? If not, what do I do? Keep digging until I reach a larger diameter sewer pipe to connect to?

Replies to this post
There are none.