Retaing Wall Q's

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Old 04-25-13, 11:00 AM
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Retaing Wall Q's

On the left side of my house i have nothing but a hill of dirt (see attached pictures). I would like to build a retaining wall to help level the area. My first thought was to build a retaining wall of pure concrete, but i prefer blocks. I have search online and got a few ideas. In theory i would like to be able to park a car or a small camper there. I have attached pictures of what i am trying to accomplish but with out the asphalt, my would just be crushed rocks.

I have found a few blocks that might be usable like the Keystone or the Basalite Geowall blocks. Is there another type of blocks i can use, something cheaper?

Any thoughts or ideas would be gratefully appreciated.

Thanks
 
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Old 04-25-13, 06:14 PM
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Absolute first thing to do is to check your zoning codes or homeowner's association restrictive covenants to see if you are even allowed to have a vehicle parking area that close to the property line. I personally would be reticent about using dry-stack blocks for a parking area in that space without engineering approval.
 
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Old 04-26-13, 08:17 AM
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Thank you for your reply.
My current zoning code does allow this. I thought i would post here and see if anyone has done something like this on there own and can give me advice. Maybe some other ideas or other ideas?
 
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Old 04-26-13, 08:34 AM
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I have used the Keystone brand blocks for over ten years and even have a fair number of retaining walls at my house made of them. It is not a cheap product but it does work. One thing I would not do is use the smaller blocks like you find at most home centers. Fiberglass pins or a lip cast into the blocks is required for a retaining wall. I am particularly fond of the Keystone because of the pins. Walls can be built vertically or with a slight slant back using the same blocks.

The only real advice I have is to follow the manufacturer's instructions and do not skimp on the base/footing. When doing a wall I figure at least 1/2 to 3/4 the time and effort will be put into preparing the foundation gravel bed and getting the first row perfectly level. Every block in the first row must be level in both directions and don't proceed until they are. Once you've done that the rest of the wall goes very quickly.

Also, if you will be doing the work I strongly suggest a good pair of safety toe work boots. I use the Compac block which are light weight at 85 pounds each. Dropping one on your foot can be a trip to the hospital without protection.
 
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Old 04-26-13, 09:11 AM
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Thank you for your advice Pilot. Especially about the boots i wouldn't have thought about that.

Keystone are not sold in my area. So my choices are Basealite Geowall Pro or the Geowall MAX blocks or Anchor blocks. I am not sure which type of blocks would be need if i went with Anchor Blocks, i am thinking DIAMOND® RETAINING WALL SYSTEM, STRAIGHT FACE
?

Thoughts?
 
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Old 05-07-13, 04:03 PM
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After calling around some place and getting some $$ figures of cost for Basealite Geowall Pro or the Geowall MAX blocks or Anchor blocks. It seems a little spendy so i was wondering if one could be a retaining with the 57-43 lb wall blocks with the lip like i have attached. These would be half the price of the ones i mentioned. I would also lay some geogrid every two courses of blocks and temper every course of block.

Has anyone built a retaining wall like this for the purpose i mentioned?
I would gratefully appreciate any feedback.
 
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Old 05-07-13, 06:08 PM
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I have never used that style of block. Will your wall be straight or have curves? Are you comparing block piece prices and if so, have you accounted for differing block sizes?
 
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Old 05-07-13, 07:16 PM
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No curves but there will be a 90 degee angle turn. Those were the only ones I found that were heavy and big that woild be able to hold the weight. They are priced at $3.77 ech.
 
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Old 05-09-13, 09:20 AM
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Anyone use this type of blocks with the lip to build a retaining wall 3ft high about 70ft long?

If i decide to go with these blocks i would add geogrid. How much geogrid would i use from front of the block to the fill dirt? and geogrid every two layers?

Can i use the geogrid with blocks with the lip?
 

Last edited by 2Quik; 05-09-13 at 09:40 AM.
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Old 05-09-13, 11:22 AM
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Did you compare blocks price based on the size of the blocks? What are the dimensions of the blocks you want to use? The Keystone Compac that I use are 18" wide by 8" high so one block makes a decent sized bit of wall. Since those blocks are solid and weigh 40-50 pounds I assume they are considerably smaller. If each block makes half as much wall it's price needs to be half the other blocks for them to be even on a per square foot basis.

I have no idea how you would use geogrid or mat with that type of block. What do the installation instructions say?
 
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Old 05-09-13, 12:20 PM
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The block size are 16in x 6in x 10 1/2 in. I can't find any instructions on how to install. I was thinking of adding geogrid to help with the weight pressure of the soil and rocks.
 
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Old 05-09-13, 01:07 PM
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In your situation geogrid is used to help tie the wall back into the soil and must be securely attached to the wall. Without a secure way of attaching the grid it's useless. With the type I use the grid hooks over the pins and the block above sandwiches it in place. Having something to positively grab the grid is critical.

What is the brand and name of blocks you are considering?

If you can't find a brand name and name of the block or if you can't find any installation instructions or guidelines than the block is probably not intended for a structural retaining wall and is more for a garden use like short, decorative retaining walls for a flower bed.
 
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Old 05-09-13, 02:00 PM
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2Quik -

According to the photos, it seems like the wall would be more than 3' high PLUS you have account to the surcharge from a vehicle. Because of this, the smaller, lighter (45-50#) units would not be best for your use.

Pins are not always necessary and many engineers so not use units with pins because of a possible "zipper" failure of the grid at the pins and prefer the lipped types that have a long history of testing for high walls. Most of the various systems offer both types of systems, but in Idaho, the variety and availability may be a problem.

Also, the photo posted of a completed wall had a vertical face. The block with lips normally have a set-back of 1"+ per course, which results in less surface are on top to recover as valuable real estate. Depending on the different types of SRWs (segmental retaining walls), that type may not be available where you are. Basalite is a reasonably large company that may not have chosen to sign up the major licensing/development and developed their own units that are slightly different and not supported with testing, approvals and detailed installation instructions.

Dick
 
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Old 05-09-13, 02:25 PM
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I have seen alot of examples of geogrid being placed on top of the block then another layer of block on top of the geogrid with out any type of pin in between.

Like the this Slope Block Installation | Western Interlock

Here is some instructions from AllenBlock on how to install the geogrid again it doesn't state you have to use a pin...
 
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Old 05-09-13, 03:12 PM
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2Quik -

Nothing wrong about using or not using a pin as long as you have a verified method (pins, lips, mass, etc.) to anchor the geogrid to the block. All of the 4 major systems (Allan Block, Anchor Wall, Keystone and Versalok) were all developed/modified/improved within 25 miles of each other within the last 25 years and are manufactured domestically and internationally. They generally have faced the same manufacturing systems, engineering standards, codes and approvals, so they all are similar. They do not license and support more than one manufacturer in a market area, consequently, many local producers tried to "reinvent the wheel" and do not provide the support and installation that the others do. That creates some gaps in information and accuracy.

I have seen 20 to 40' high walls in the U.S., Europe, Australia, South America and other localities and they are a mix of pinned and lipped systems, but they are done correctly. Within 10 miles of my home, there are 40 or 50 walls between 5' and 40' using the mix of SRWs of the various systems.

If you look at the units in the previous post, you will find the units are only 8" long in the wall, but they do have a positive geo-grid lock. Why anyone would consider putting a SRW wall system on a concrete footing, especially for high wall, is beyond me and sound engineering judgement. The system is designed to be installed on a compacted soil base and not a rigid concrete footing.

Landscapers have their own little world and offten get beyond their technical abilities, so municipalities have been forced to have higher walls (over 3, 4 or 5') to be designed by a engineer because of the history of problems.

Dick
 
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Old 05-09-13, 06:01 PM
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I am just concerned that through all of this you have not said the brand or specific block that you will be using. And you seem to have linked to blocks that you are NOT using. This is not the sort of thing you can take the installation instructions from block A and apply to block B that you get from the local home center.
 
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Old 05-10-13, 08:55 AM
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The only thing i can find on them is that there called Mutual Materials 6 in. x 16 in. Concrete Wall Blocks, Build retaining walls up to 3-1/2 ft. high with the Mutual Materials 12 in. x 16 in

There are at my local home depot. I will be going to some garden centers this weekend.

Thanks.
 
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Old 05-10-13, 09:42 AM
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I would not use those blocks in your situation. They seem fine for a garden project but not the correct block for a structural retaining wall.
 
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