Help with retaining wall

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Old 08-13-15, 06:41 PM
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Help with retaining wall

Hopefully this is the right place to ask this. We bought our first house a few months ago and have some things to do. My first project is to build a retaining wall but I have never done one before. I already ripped out the old one and dug the trench to put it where I want.

I have read so many websites that I am starting to get confused. This particular wall is going to be concrete block and only 2 feet tall. I was originally going to pour a concrete block as my base but people seem to say that you only need crushed stone as a base.

Also since it is a short wall and I am using mortar with concrete block so I need to step the wall back, lean it, or just build it straight up?

Thoughts?
 
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Old 08-13-15, 07:08 PM
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IMO - Setting a concrete block retaining wall retaining wall is a tough project to make look good, especially for a first timer. * Note: by "concrete block" I am envisioning the type used for building basement walls.

Now, if you are using a "keystone" block, or some other type of landscape block, you would not use mortar. At the very most you would only use landscape block adhesive. Some blocks are only dry stacked.

You should not pour a "pad" for your base, frost will heave it in no time. Follow the manufacture's recommendation on how to lay the landscape block.
 
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Old 08-13-15, 08:03 PM
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Yes you are correct that it is just standard cement block. I am not worried about it looking bad because there will be a deck that goes over it and some other covering to hide the stone. I decided to use block because it is by far the cheapest route. The more Web sites I read the more I get confused. Everyone seems to have a different idea in how to do it.

I guess it makes sense though to not use concrete unless I am digging 4 feet down to get below the frost line which I was not planning on doing.

So if I use a gravel base, would you use leveling sand on top of the gravel?
 
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Old 08-14-15, 05:43 AM
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The crushed & compacted stone base is only used with dry stack retaining wall blocks. For a CMU (cinder block) wall you would need a proper, poured concrete footer.
 
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Old 08-15-15, 10:00 AM
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I went to a landscaping place this morning and talked with them. They basically said the same thing as mentioned already. Cinder block wall would need; concrete base under frost line which is approx 2 feet, drainage system behind wall, and they are not good for use as a retaining wall.

What I am now going to do is just use dry stacking block. My area us dug out already but I need to dig about 8 inches more into the hillside because I had it dug for cinder blocks which are half the width. I had my base material delivered already which was limestone dust and I think crushed limestone.

Now I need to find block cheap somewhere. I was planning spending 1.10 on cinder blocks but the normal retaining wall blocks are nearly $9 each. I saw someone selling some on Craigslist so that may be an option.
 
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Old 08-15-15, 10:12 AM
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I think your revised plan will be better in the long run.

Check the home stores for landscape blocks that you like. Typically they are quite a bit less than a landscape supplier.
 
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Old 08-15-15, 02:57 PM
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If you are using proper, dry stack retaining wall blocks I like to wear safety toed shoes when working. They run 60-100 pounds each. The first ones aren't so bad but toward the end of the day they like to slip from your grip and your feet tend to be underneath them.

Also follow the installation instructions for the blocks you choose. DO NOT skimp on the base, compaction or leveling the first row. 75% of the work is in the base and getting the first row level. After that it moves quickly.
 
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Old 08-16-15, 07:15 PM
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I totally lucked put today. My uncle is also doing a retaining wall. He found keystone blocks from somewhere that had a bad form. There Is a tiny piece of concrete on the top/back that was left on. It just takes a chisel and hammer to knock them off. He is getting them for $2 a block including the pins.

It's funny that you mention steel toed shoes. I dropped a cinder block on my toe today. I thought it was broken but it is fine now.
 
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Old 08-17-15, 05:08 AM
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I have used the Keystone blocks for many years and they work very well. $2 with pins is a great price.
 
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Old 08-29-15, 05:44 AM
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I am picking up my blocks today. Price ended up being a little different than told but still a good price. I am getting 85 blocks, 24 toppers, and 6 corners, and pins for $250.

My new question is. When I went to landscape place to get gravel I was told that I need limestone with dust as base which I got. They said I need small round pebbles (can't remember what they actually are) for filling the wall and 2b limestone for backfill which is larger limestone. Do I really need different rock for inside the wall? My uncle who gave me the wall is using the same gravel for all 3 areas but when I was over his house it looked like he had smaller limestone maybe 1b and not the larger rocks that the landscape people told me to use.

Not sure if the 1b and 2b terms are just the landscape places way of saying it or if that is actual terms. I am not sure what the actual size of the rocks are.
 
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Old 08-29-15, 09:00 AM
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The specifics of limestone versus other rock types is not really important. The exact flavor will depend on the quarry where it's mined.

You want various sizes of sharp, angular crushed stone for the base and dust helps. The variety of sizes and rough shape allows it to be compacted with the smaller stones filling the gaps between bigger rocks and dust in the tiny cracks. When properly compacted is becomes extremely solid and able to support a lot of weight. The downside is with all the nooks and crannies filled it does not let water move through it very well or at all. So, inside the blocks and behind the wall you want clean stones of a uniform size. No matter how they settle there is always a good void space between the stones for drainage.
 
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Old 08-29-15, 03:01 PM
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we just use #57 stone - IF i can get the pic attached, you'll see what 2 guys did last thursday,,, we did cheat a bit by using the existing curb for a base incl some 57stone behind it,,, the property manager was blown away by it compared to the rotted rr tie wall,,, she even asked us to paint it so we put on either a coat of invisible paint OR conc gray & charged her another $988 :-)
 
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Old 08-29-15, 03:05 PM
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jk about the paint BUT she did offer to pay us to paint it,,, n s !

otoh, the company i worked for previously had some woodchuck put in a wall about 5' x 100 - $16K - but its falling down,,, no drainage, no flex footing, wrong method for the chosen block - these walls aren't difficult BUT there are tricks to know,,, anyway, another client left them & came to us which is a plus,,, by the time the lawsuit's settled, we'll have the wall down & rebuilt properly,,, obviously building it right costs more & we already know the original price :-) so there's an add-on + we have to dismantle the existing,,, God is good !
 
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Old 08-30-15, 03:46 PM
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Spent 12 hours today in 88 degree temp and dew point of 65. It was miserable, but I got my trenches finished, layer and tamped the base, and ran fort row. I am happy with it so far. It was a pain to keep it straight and level.

The only thing that I did not do correctly was the amount of backfill I am going to use. There is only 8 inches behind the wall that will be limestone. It was really hard digging by hand because it was all shale and sandstone. I figure I am only going 2 feet high and I have an 8 inch base so I decided to not dig out any further.
 
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Old 08-31-15, 05:11 AM
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Getting the first row set is a chore. You'll be amazed how fast it goes once you move onto the upper layers. That's when you get the payback for the doing the first row properly. Things go so fast you're limited by how fast you can move the blocks & stone.
 
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Old 08-31-15, 11:56 AM
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First wall is done minus the toppers. Forgot to load them in the truck so I am getting them tonight. I did this entire process by hand and have never sweated as much in my life. I feel accomplished with doing this type of project on my own. My dad did help move some gravel so not all on my own

Pics to follow tomorrow.
 
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Old 09-01-15, 02:29 AM
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the satisfaction of/from the hark work necessary in completing a task is something many will never have known,,, you're a fortunate young man well-done !!!!!!!!!!!!!!
 
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Old 09-05-15, 02:00 PM
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Ok finally got to a computer to post this picture. It is a small wall but a lot of work went into it. This was a pic before the toppers and the final dirt back fill was added.

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Old 09-05-15, 02:20 PM
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ugg I had a long post typed but storm knocked out internet for a min.

to shorten the post; I have 1 more question. I removed the back retaining wall today which was sandstone. I am putting up the same wall as the front. No rain in forecast but it has been storming heavily for the last 45 minutes. Such great timing, right after I removed a wall.

The foundation is sandstone. In some spots the previous owners put mortar between the rocks to keep water out. Now that I have removed the wall which had only dirt behind should I fill in the sandstone foundation with anything to keep water out of the house. I am concerned that when I backfill 12 inches of limestone that when it drains it may make it into the foundation. I was thinking of either filling in the wall with cement or mortar plus putting in a french drain for a few feet just to divert it away from the house if it makes it to the bottom of the limestone. What would everyone else do in this case?

If pics are needed, I can take one tomorrow.
 
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Old 09-09-15, 09:29 PM
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Why not install a perforated, rigid drainage pipe behind the wall, to carry all water away from the foundation? Slope it 1/4" per foot, with an outfall to daylight.

P.S. Thanx for letting me hit the hallowed 3000 posts plateau.
 
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Old 09-10-15, 01:32 AM
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I do plan on doing that as well, was just worried about extra water beyond that. Maybe I am overthinking it.
 
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