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Dry stack cinder block wall with 'mud brick' mix for grout

Dry stack cinder block wall with 'mud brick' mix for grout

Dry stack cinder block wall with 'mud brick' mix for grout

(OP)
Hi all, if I haven't managed to offend the relevant folk in another forum would love any input on this idea.

I live in the high desert in California, and am looking at putting in a couple of fairly small raised beds (~ 4 courses of cinder blocks for about waist height for my 5'4" wife) in the garden for some herbs etc.

Per earthquake building regs they don't need reinforcing or mortar etc. at this height but just for strength I'm looking at grouting with some wet dirt with straw or something in it and putting in bamboo canes as 'rebar'. Essentially using mud brick construction with the cinder blocks as former's.

Based on the state of some of the dried out mud around here after a rain storm, and being in the Adobe region I figure this should work while saving $ and hassle on mortar and concrete etc. Plus I have a bunch of spare dirt and dried out sod from xeroscaping my front yard last year which this will help use up.

I did a bunch of searching on mud bricks etc. a while back which is where I got the bamboo 'rebar' idea, but I haven't been able to find reference to doing this 'wet dirt grout' - any input from anyone appreciated.

Cheers,

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What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: Dry stack cinder block wall with 'mud brick' mix for grout

I do not think that adobe will do well in contact with wet earth, which garden soil certainly will be. A polyethylene liner could make it work. I suggest you look into straw bale gardening.

https://www.google.com/search?q=straw+bale+garden&...

RE: Dry stack cinder block wall with 'mud brick' mix for grout

(OP)
The mud fill wouldn't be in direct contact, I plan on sealing inside to avoid any leaching of chemicals from the block anyway. Plus even with irrigation things stay pretty dry here😃. But good point, I may have to improve my sealing/ lining.

For multiple reasons straw bales won't be an option.

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: Dry stack cinder block wall with 'mud brick' mix for grout

We tried something similar at out cabin (Big Bear Lake), after about 2 years the cinder block started to move around and come apart. We ended up redoing it and just used mortar on the joints. Our "rebar" was a bunch of plastic chain link fence fillers someone dumped in our yard, we stuffed a couple in each hole, and packed dirt in around it. So far so good after 6 years.

While we probably get more water up there than you do, it still gets real dry most of the year.

MikeL

RE: Dry stack cinder block wall with 'mud brick' mix for grout

(OP)
Thanks Mike, Did you use just dirt or did it have straw or similar in it as well? I assume the dirt was wet and you tamped it down well initially.

Maybe I'll use a little structural adhesive, used some to resecure a cap on my front wall a few years back and it was easy to use and has lasted well.

I'm thinking about how best to 'cap' it - did you leave yours open?

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

RE: Dry stack cinder block wall with 'mud brick' mix for grout

Why not just use the retaining wall blocks that have a lip on the bottom of the back. Each course steps in by the width of the lip rather than straight up, but they lock together from the pressure of the dirt behind.

RE: Dry stack cinder block wall with 'mud brick' mix for grout

The dirt had a lot of pine needles, we wet it and tamped it down, we capped it with some salvaged planks that my wife liked the look of that we anchored at the corners.

I helped a neighbor do a similar project (some tool dumped a bunch of damaged cinder blocks at an empty lot behind my cabin, that was the source of our community material), on his we didn't fill the holes quite to the top with dirt, added some gravel and did a mortar cap with a bit of a slope. It wasn't very big but it came out nice.

So other than some sweat and a couple of bags of mortar, it didn't cost anything and kept me from hauling the stuff to the dump and paying a fee for someone else's trash.

MikeL

RE: Dry stack cinder block wall with 'mud brick' mix for grout

There is a wealth of data on the net, and many many studies in mud-brick construction, I did a lot of work with a brother-in-law during his PhD thesis on mud-brick construction for active seismic areas, my input was hands on - very little academic "stuff" so can't point you in right direction for research papers, other than saying the data is there.
It is certainly an interesting area of study.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: Dry stack cinder block wall with 'mud brick' mix for grout

(OP)
davidbeach - for several reasons including aesthetic, functional, space and perhaps most importantly $ (they were quite a bit more expensive than cinder block) they aren't a great option for my situation.

catserveng - thanks for the additional input. I'm thinking a mortar cap, sloped into the raised beds to make the most of the little rain we get but we'll see. You with the blocks is kind o like me with all the extra dirt I've accumulated!winky smile

Artisi - I did quite a bit of digging a while back when I first had this idea and found lots of info on mud brick like you say. I looked again before posting this question and still didn't find quite this idea. Closest I got was the exact opposite - mud brick wall with mortar grout! I figure mine is kind of like rammed earth but leaving the forms in place.

Posting guidelines FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? (probably not aimed specifically at you)
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?

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