Retaining Wall


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Old 02-18-11, 08:58 AM
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Retaining Wall

So a portion of my back yard has a slope that I would like to build a retaining wall on to gain some extra yard.

This is a image of the slope.


The top of the slope has a old chain link fence that is on the property line (neighbor's). There is a 5' easement (utilities) on both sides of this fence. I measured the mound to be between 5 and 6 feet tall (level ground to bottom of fence). How tall of a retaining wall would I need to hold the soil back properly?

I had two assumption.

(1) If I put a retaining wall outside of the easement (5 feet from fence) the mound is only 3 feet tall and I assume that a 3 foot retaining wall would work. This would leave a 2-to-3 foot mound above the wall's top.

(2) If (1) does not work. I would have to build a 5-to-6 foot retaining wall outside of the easement and backfill to the fence to have a level top.
 
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Old 02-18-11, 09:44 AM
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I take it that you want the useable yard to be at the base of the wall and not the top? If that is true, I wouldn't worry about making at level above the retaining wall you build. You can have it slope down to the top of the wall. Now how much of a slope would be up to you. If that is going to be grass on top, make sure it isn't too steep to mow. I also wonder if a certain height of wall will require you to have a railing.
 
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Old 02-18-11, 10:28 AM
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Yes the base of the wall would be my usable yard. This mound was created when the lot was cleared.

If I go with the 3 foot wall will the sloped soil above the wall wash over the wall?

For either wall heights I will plant juniper or phlox on top to remove the need of mowing.
 
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Old 02-18-11, 10:50 AM
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If you have a slope above the wall, the soil may wash down or may not depending on the slope above and the ground cover.

Two things to look at -

1. Check to see if the are any limitation on filling over the easement area. Whoever is granted the easement may have rights to control this.

2. Check you local code to see what the maximum wall height is for an unengineered wall. In some localities the cut-off limit is 4' and is 5' is some areas. There are some unique requirements and the slope above could be considered a part of the load on the wall.

Avoid getting into a rigid concrete wall because of the cost, excavation and footing construction. A mortarless segmental retaining wall (SRW) is much more economical and gives a more aesthetic appearance and it is more DIY friendly. There are number of different very similar systems that all have great web sites with ideas, design concepts and installation instructions. No concrete footing is recommended or permitted for this system.


You may want to have someone do the dirt work and backfilling because the have the equipment. Laying the block is hard work, but simple once you have the first course set in place on the shallow gravel base.

Dick
 
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Old 02-18-11, 11:13 AM
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Originally Posted by msalley370
Yes the base of the wall would be my usable yard. This mound was created when the lot was cleared.

If I go with the 3 foot wall will the sloped soil above the wall wash over the wall?

For either wall heights I will plant juniper or phlox on top to remove the need of mowing.
You will need something on top of the dirt. Put lots of mulch up there around whatever you plant. You can also fill behind the wall up until you hit the bottom of the cap block. That way any soid that wants to run off will hit the back of the wall. That should give you plenty of time to get your erosion control landscaping in place and working.
 
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Old 02-18-11, 01:34 PM
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follow what concretemasonry said...... depending on the type of wall you are going to install (versa-lok, poured wall, splitface, wood tie, etc..) if costs arent prohibitive put in 2 tiers, this way you will no doubt meet code by the wall being under 4ft & the slope load will be split hopefully evenly between the upper & lower wall

personally I would build a versalok wall..........push it to the code limit in height, use versagrid, follow mfg building rules & go from there (if the slope is only 5-6ft that is).



LXT...............
 
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Old 02-20-11, 02:41 AM
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Exactly like Dick said -- check with whoever has that easment before you do anything, and use a mortarless segmented block for the wall. What name they go by depends on where you buy them and who made the ones available where you are.

Installation is very straight forward. A trench wide enough for the block to fit in and deep enough for an inch or so of base and for the 1st course to be below grade. That 1st course will require about 90% of the work. After that, you are just stacking blocks.
 
 

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