Double thick wall

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Old 08-07-12, 03:08 AM
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Double thick wall

I'm considering laying a 1' tall retaining wall double width just to make sure it never needs replacing.

I read about the different types of bonds, but what I haven't been able to find out yet is how you actually lay the bricks double thick. Do you lay down one side of one row and then do the other side once you're done with the entire first side? Or do you lay them both at the same time?

Also, the mortar between the two sides of each row. Do you butter the side of the brick? So you'd need to butter the side and the end for each brick of the second side of the row?

Thanks.
 
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Old 08-07-12, 04:01 AM
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You are using the term "bricks" . Retaining walls aren't built using bricks. They are too small and will topple to easily. You need to lay in a concrete block wall with deadmen support along the run. You can veneer the concrete block with brick for looks, but that's about it.
 
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Old 08-07-12, 03:20 PM
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No, I'm definitely using bricks.
 
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Old 08-07-12, 03:36 PM
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You could possibly get away with bricks performing adequately, since the wall is only a foot tall. But you'll have a much more durable structure if you use 6"-wide concrete blocks for the rear 2 courses, faced with bricks in front. Everything on a slightly recessed continuous concrete footing (to get the 1' height you want using 2 courses of 8" tall block), and the brick facing tied to the block courses with brick ties. I'd cap everything with bricks placed on edge, transverse to the wall line, with a parallel starter row in back to get the finished width you need, and maybe a small front cantilever (1"?) for balance.
 
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Old 08-07-12, 04:04 PM
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If you put mortar on the inside faces of the brick (to fill the "collar joint") it would be stronger than than 2 separate brick per course. Since you are using mortar, you will need a concrete footing.

The segmental retaining wall block that are in different sizes, colors and surface treatments and they would actually work better for possibly be stronger. They do not need mortar or a concrete footing and are placed on a level compacted gravel base as the recommendations state.

Dick
 
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Old 08-26-12, 01:11 AM
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Guys, look, thanks.....but I don't need alternate suggestions. I've already spent a lot of time considering the alternatives and this is what's going to work for me. I'm just looking for an answer to my original question. I've even gone through a couple books and haven't found the info. Any guidance would be appreciated.
 
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Old 08-26-12, 02:19 AM
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It's a shame you refuse to listen to the good advice here. Why do you insist on the 2 rows of brick, when 1 row as a facing on concrete block would be much quicker, stronger and work far better?

But if you refuse to listen to us, then go ahead with your 2 rows of brick plan. And you can count on repairing it in a year or two, because it won't be strong enough to resist the forces of wet earth pushing on it. At least do a tie-bond pattern, running every third brick at right angles to the rows. That way it might last 4 years before you need to rebuild it.
 
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Old 08-26-12, 03:57 AM
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English bond is one of the strongest bonds to use. You don't need to butter the inside as you lay them, just the head joints. When you have done both rows fill the middle with a dryer mix so the brickwork does not belly out. Then lay the header course. It's actually better to start off with headers as this gives you the correct width to work to. Having headers every other course ties it together better.
A key point with retaining walls is the drainage, although in California it may not be so much of a problem.
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Old 08-26-12, 04:00 AM
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The reason you haven't found any information in books or other sources, is because what you are planning is not normal construction methods. It will fail. Only time will tell. Good luck with your project and let us know if we can help further. Post some pictures when you are through, too, as we are interested in finished projects.http://www.doityourself.com/forum/el...your-post.html
 
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Old 08-27-12, 02:48 PM
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Why does everyone seem to think his wall will fail? At 12" high it will not be under any great lateral pressure and the thickness he is proposing will be fine.

If the bricks are solid and flat on the bed-face (ie not perforated or having frogs)
a 4" strip of expanded metal laid about mid-height would give extra strength.

The big killer of brick retaining walls is frost and sulphate attack.
 
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Old 09-02-12, 12:25 PM
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Thank you very much. That answered my questions.

If I go with an English bond, I'm filling in the void every other row, right? Am I better off using those metal ties?

Also, these are cored bricks with the three holes through the middle. Anything particular about those I need to take into account?

Thanks again.
 
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Old 09-02-12, 04:47 PM
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There is no need for ties as the headers do this for you. Cored bricks are easy to lay and need no special measures. Just keep the bed joints about 3/8 inch.
Every other course for filling the void. On site the void isn't always filled, as some mortar will drop in when the header course is laid. This is a really strong bond often used to build houses with that have lasted hundreds of years.
 
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Old 09-03-12, 06:20 AM
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Sorry, I missed the 12" high thingy. Which brings me to.....why? For decoration only? I mean, that ain't a big wall. What will it retain? Just curious.
 
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Old 09-04-12, 01:48 PM
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Maybe it's just to retain a flower bed/planter or something similar.
If the bricks have holes (perforated) he wouldn't need any expamet as the mortar binds into the holes.
The wall needs to have no great strength, but the bricks must be suitably frost/sulphate resistant.
 
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Old 09-05-12, 08:58 AM
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at 12" high I agree that the lateral forces will not be great but there is still a chance that the pressure on the backside will 'roll' the wall forward over time. I did a walk around my block and counted 6 different locations where walls of 12" or less were leaning because of back-side pressure. One is at the side of my house where a 8" tall timber retaining wall is leaning because the front edge is sinking more into the earth than the back edge. It did take years for this to become evident but it can happen. The 12" brick wall may be just fine but given a decade or so I would expect it to be visually off. Good Luck.
 
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Old 09-05-12, 11:07 AM
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You do need a footing under a brick wall so the wall does not roll forward from the backfill (can be up to 90 psf/cf or is subjected to differential settlement from moisture changes or heaving from either wetting/drying or frost(in some climates) that can cause cracks rapidly between the brick and mortar. A 8" thick brick wall without a footing will roll as much as a cheap timber/wood wall if there was no footing and any differential settlement will be much more noticeable since it is a rigid wall and can crack easily from a one time high loading due to excess moisture in the soil behind the wall.

Building a good wall (even only 12") requires more than a predetermined selection of material since many materials are not really designed for the purpose.

Dick
 
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Old 09-27-12, 08:39 PM
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One side of our backyard is about 12" lower than the house behind us which is the highest point on the hill the neighborhood was built on. Granted, I could probably do without a retaining wall, but the area behind the retaining wall is going to be a large raised bed garden about 800 sq ft not including the walkways.

Another question. Because these are the cored bricks, what do I do about the top row? I thought I could buy enough solid bricks to create the header or even go with a more decoarative stone or brick. It also occurred to me I could just lay these on their side, but I'm not sure how I could keep from ending up with some joints lining up with the previous course. Would that hurt or should I just go pick up some solid bricks for the top?
 
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