Gardening and Horticulture - Sealing a Retaining Wall

I bought a house about a year ago, which sits on a gradual slope. The backyard has a 2-3 level rail-road-tie retaining wall. Every time it rains the runoff from uphill, along with a lot of saturated Oklahoma clay, washes through the gaps between the ties. I'm wondering if anyone has any good ideas on how to seal this thing up so the water runs off the sides and the clay stays in place. I don't mind tearing it up and rebuilding it, but I'd like to stick with the ties rather than using a different material.

Hello ClayOKC and Welcome to the Lawn Forum :)

If there are substantial gaps between the courses of ties, excavating behind the wall and putting a permiable fabric (landscape fabric) against the back of the wall should help (depending on how fine Oklahoma clay is...) It probably wouldn't hurt to put about 6" of crushed gravel against the fabric before backfilling with the native soil, also. This should filter out the soil particles while allowing water to pass thru.

For a wall 3- 4 courses (approx 15" - 20" ) high, you should allow water to drain thru or provide holes for it to pass to avoid a buildup of hydrostatic pressure which could either topple or undermine the wall. Surface runoff could pass over the wall if the top level is even with the top of the wall before it has a chance to percolate down.

I'm going to copy your post over to Gardening and Outdoor Living so that more Members will have a chance to answer your question...

Hopefully some will add their experiences with similar situations.

(Fellow Members: For the sake of simplicity, please post your replies in the Lawns forum so ClayOKC doesn't have to jump between forums ;) )

Good Luck

Howie