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We've got a 50' stretch of yard that has a very gentle side to side slope that we can't easily eliminate (fences on each side built at different heights). We want to build a retaining wall along that stretch. The wall will be 6" to 10" high. (Two or three layers of 4" block with the first layer dug 2" below the lower elevation.)

Can a retaining wall be built at a gentle side to side angle so that the top of the wall is flush to the gently sloping level of the higher elevation? We'd like to avoid stepping the wall. Are there any special considerations for a wall such as this?

Edit: the reason I'm asking is, much of what I've read says it's important that the first course of blocks is level both front to back and side to side.

Edit 2: Mark's post taught me you can add photos, so here are some:

From the house

Along the wall high to low

Along the wall low to high

Jakerc
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2 Answers2

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I built a retaining wall in a situation very similar to what you described. In my case the wall drops approximately 12" over 40 feet. It has 3 courses of 6" Keystone wall blocks. The first course is mostly buried and the wall is about 12" high over most of it's length. I also put about 4" - 5" inches of drain rock behind it with a landscape fabric barrier.

This was 15 years ago and it seems to be holding up just fine. I would hope that the 4" blocks you want to use will be ok. However, I've worked with that size some doing garden walls and they are definitely less stable than the bigger blocks.

One other consideration here is aesthetics. Make sure looking at a retaining wall that isn't level doesn't bug you! Sometimes I look at mine and wish I had installed it level and stepped it down instead.

In the area where I live we have an assortment of gravity block retaining walls and the ones that follow the slope usually don't look as good in my opinion.

Here is a photo for reference: enter image description here

Mark Edington
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If the wall isn't level gravity will be forever forcing it to fail.

It sounds like you're planning to run the wall in the direction of the slope, so what is it retaining? There are landscaping blocks with finish on both sides, but most are made to be backfilled behind them. And the backfilling isn't optional, its an integral part of the wall system.

It's one thing to place some garden blocks around a small area to hold back some mulch with the understanding that you'll probably have to redo it every few years to keep it looking nice, but if you want to build a nice looking long lasting wall, you have to go the whole nine yards. And that means for a 50' wall, you should use a full size wall block, excavate a few yards of soil (probably using a machine), backfill with a couple yards of crushed stone, compact the crushed stone (probably with a machine) and pound each base block into the crushed stone.

If you just scrape the ground a couple of inches and go 50' with small garden blocks, it will be a crooked mess in just a few years whether it's originally level or not.

Rand
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