I am building a 3.5 foot retaining wall using blocks with locking lip. I put 4 inch perforated pipe at bottom of base. Then backfilled with 57 limestone. I have one row to go. But it rained last night. And when I went out to work on wall I noticed water at the base of the wall. I have clay soil. I was wondering if that is ok. Or if I can add another drain pipe along the base of wall on the outside. By the way, I have about 2 feet of backfill behind the wall and the blocks I am using are 8 in. Tall, 18 inches wide at the front, about 80 pounds each. Thanks

 

It sounds like you have it right, you say you saw some water, exactly where was this?

Would say not unusual to see some water after a rain!

 

Clay holds water very well so it's not unusual to see puddles after a rain. You want the ground sloped so the water drains away but I wouldn't do anything drastic like installing drain pipe on the outside of the wall.

If you will be planting grass or other plants atop the retaining wall I usually stop the stone about 8-12" below final grade so there is soil for the plants.

 

The water was coming out from behind the wall, through the base blocks. And settling. There wasn't a lot of water. But when I vacuumed the small puddle, I could see more water coming from behind the wall.

 

That's one of the nice features of pre-cast block retaining walls. They tend to have good drainage. I think that's part of why they work so well.

 

Yeah. I tend to worry when I dont need to. I just dont want the wall to fall down in a few years.