Patio retaining wall block

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Old 08-13-11, 05:17 AM
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Patio retaining wall block

Hello,

My wife and I are considering building a raised patio. We were thinking of having it raised apporx 16" off the ground or so and have only a single step down to the ground. We were looking at a local home store and they have some block wiht the following sizes we were interested in:

1. 8"hx17"wx12"d -lip
2. 3.5"hx11.5"wx7"d -no lip
3. 5"hx15"wx9"d -lip

with the height we are looking at building this would we be bettter off getting the smaller block then the large?

How about as far as looks go, would it look odd having such a larger clock in a retaining wall that isn't really that high?

Finally the one block does not have a lip on each block. (not sure the name but the lip would prevent the blocks from sliding. ) Is this a big deal for this tall of a wall or dont we need to worry about this really?

Thanks for th ehelp
 
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Old 08-13-11, 07:17 AM
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Is the block for the perimeter only & something else will be in the middle? I assume you meant larger block & not larger clock. Is that correct? Mortar would be between the layers, so a lip isn't needed. I would go for the 8" block.
 
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Old 08-13-11, 08:25 AM
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Thanks for the reply and you are right i meant block. Sorry about that.

These blocks would house the compacted class 5 that would be used for the patio stones. Does that make sense?

Mortar is required between all of these? Can i get away without using mortar if i went 8-12" lets say?
 
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Old 08-13-11, 04:00 PM
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Some blocks can be used without mortar. Check with the people at the stone yard to verify the best method. Personally, I like the added strength.
 
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Old 08-13-11, 04:16 PM
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Personally I like to use larger block sizes whenever possible. They are heavy to lift but it takes fewer of them to build the wall and I think their larger size & mass makes them stay in place a bit better.
 
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Old 08-13-11, 04:46 PM
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The SRW block you described are meant to be used without any mortar or a concrete footing, with the exception of the ones without a lip. The latter are just for landscaping purposes unless pins between the block are used for shear resistance.

SRWs can be used for gravity walls 4' to 5' high anywhere and above that up to 40' high with geo-grid used to stabilize the soil in an engineered application (never with mortar or a concrete footing).

That is reason they are the most commonly used retaining wall systems in the world.

If you go to the big box retailer they could give you the name of the local manufacturer and possibly the name of one of the four major systems used internationally and they each have very good web sites with ideas, examples ind installation instructions.

Dick
 
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Old 08-13-11, 06:58 PM
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Thanks again for all of the replies.

This is the picture we were kind of going off of that we like.

Catalina Wall used in a raised patio application. - Photo Gallery's Photos | SmugMug

I do need to clarify one thing after doing some measuring and further reading. I can't have it raised as high as i like and extended a few level lines out to get an idea of the slope. I can only have block about 4 inches above grade at the highest spot as if i went any higher i would be concerned with having the patio equal to or higher than my foundation. if i have it about 4 inches it looked to be about 3-4 inches lower than the foundation so I think that would be OK.

i have about 8" of slope from the foundation out the 16' we want to go.

If we were to use the block similar to the picture above I am guessing this is an application where mortar would be required to hold the block in place?

i think at the lowest point, knowing the information above, I would have maybe 2 of the larger blocks stacked is all.

Thanks again for the help.
 
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Old 08-13-11, 07:40 PM
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i see a lot of people seem to use adhesive for these type of blocks. will that hold a wall from buckling?
 
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Old 08-13-11, 08:36 PM
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There is no indication whether the block you are trying to use is one of the national products, with back-up and instructions. It is likely it is a local "knock-off" with no real standards except pretty pictures.

As I mentioned previously, these type of units are not intended to be mortared together (for many reasons) and a concrete footing should not be used.

I would be reluctant to use a unit without any shear resistance (cast lip of expensive pins) for long term stability reasons, especially if it is supporting a paver patio, that requires some stability. For such a small load, "buckling" is not a factor, but sliding could be, especially if you are in a cold climate that can destroy and rigid adhesive in a season.

It should not be hard to find the name of the manufacturer from the store or by looking at the pallet identification. Once you have that, it is easy to find out what products you are considering to find installation instructions and recommendations. You will not find that for a knock-off product, that is usually made by a small producer. Most larger retailers sell one of the major products/systems because of the support that can be available.

Dick
 
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Old 08-13-11, 08:40 PM
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The block in the main picture of your link appears to be dry stack (no mortar).

The key to any retaining wall or patio is it's foundation. No adhesive or mortar will hold a wall together without the proper foundation to stand upon.
 
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Old 08-13-11, 09:29 PM
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The foundation s the key and it must be a well compacted base (not concrete) that is absolutely level. After that, with the right units, it is just kids play. For the cap units at the top, 4 dabs of silicone adhesion will hold the cap units in place and still not lose the battle with Mother Nature that does not like rigid walls.

Dick
 
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Old 08-14-11, 06:55 PM
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I called the local home store that has something similar (Menards) and all they could tell me about them was they were made by midwest manufacturing which I know is a menards owned manufacturer. There is nothing on there website either about how they would be installed in a raised patio scenario either. The guy i talked with said to glue them and it should be just fine but I was not confident any his answer at all.

Can anyone tell me that how deep i need these in the ground and if i am out 16 feet and have a difference in elevation of 8" how many of these i would need stacked at the lowest point?

Thanks again everyone for the help.
 
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Old 08-15-11, 01:01 AM
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Glue? What kind of glue did he recommend?
 
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Old 08-15-11, 06:06 AM
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he recommended using some construction adhesive or the stuff specifically for landscape block but thought the construction adhesive would be sufficient.

I get a little concerned with that as I do live in ND and Concretemasonry had mentioned about them becoming less effective in certain climates. we go the extreme both in hot and cold so the climate might test this?
 

Last edited by olson2334; 08-15-11 at 06:23 AM.
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Old 08-15-11, 06:54 AM
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I don't see how mortar could hurt.
 
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Old 08-15-11, 07:20 AM
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Mortar would be OK if you poured a concrete foundation/footer and built up a wall using cement block or brick but it is unsuitable for a retaining wall sitting on a gravel base, especially if the retaining blocks are designed to be dry stacked (no mortar).

Ordinary construction adhesive may be OK in certain climates & applications but up north I think you need the proper product to survive the winters. There are special masonry adhesives designed for exterior use that would be much more reliable. Some have rather specific installation instructions so make sure you read and follow the directions. Many are not just simple glues you squirt on. They must be installed properly in order to work.

How deep into the ground you need to go will depend on the blocks you choose. Also, you will have to dig deeper to install the proper base as recommended by the manufacturer. I would not use a product that does not have instructions for anything more than edging a flower bed since you have no idea of knowing if your application is right for that product. Here are some basic retaining wall installation instructions that will give you an idea of what's required.
 
 

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