waterproof a cinderblock retaining wall?

[B]

I'm going to build a cinderblock retaining wall in my yard to "hold back" heavy clay soil. The wall will be 24 inches high (three cinderblocks) on a poured foundation. All exposed surface will be covered with artificial stone.

Should the blocks be filled with cement or left hollow? Should the back side be waterproofed, and with what material?

Thanks

-B

[DanG]

I would not do it your way. Solid retaining walls are under considerable stress due to hydrostatic pressure.

If you make the block and stone wall, it is imperative that you design it to let water out. This can be accomplished by installing a gravel drainage bed on the back side of the wall protected by a geotextile with drain pipes through the wall at about every 4 feet. A true retaining wall requires a footing able to resist rollover. This means either a substantial heel or toe for the wall with rebar (1/2" is fine) L bars extended up through the block and concrete filled. I think I would use a trough block on top with horizontal steel and slushed.

There is an easier way using garden wall blocks unless you really object to the look. The whole premise is that the wall is not solid and has gravel behind it to allow water to go through the wall, not fight it. The footing is gravel.

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