Cool. I took soils engineering in college. This was the book we used
formatting link
and Lambe was the professor. He was a bit of a dick and a mediocre teacher but he knew his stuff. What did you study?
You've seen nothing of mine. I don't know why you have your knickers in a twist. The manufacturers specifically state that for walls 3' or under there is no tie back required for a gravity retaining wall. For walls over 18" they instruct you to install drainage behind the wall with graded fill. That's it. No engineering required.
But of course the manufacturers of interlocking block probably don't know anything at all about soils and engineering. Maybe you'd like to contact them and have them revise their installation manuals to please you?
You seem to be the one with knickers in a twist. BTW - drainage and anything else about designing a retaining wall so that it will stay where it is put "is" engineering. I guess that means you must have flunked the class.
Nope. Hated it, passed it. Only good thing about it was we got to go on a trip to Vermont for our final presentation.
So the guy reading the installation manual is doing "engineering"? Interesting. I always thought it was more complicated than that. Too bad the backpedaling can't be converted into forward motion - you'd really be flying!
You wrote this: "A good retaining wall that will hold up needs a bit of engineering. It needs substantial anchoring back into the hillside and proper drainage. Otherwise, tons of hydrostaic pressure can build up behind it and push it over. It's not just a simple stack of blocks."
Your point was that engineering was needed, implying, obviously, that the OP needed to have the 30" high retaining wall designed, which is not the case. And, actually, it is as simple as stacking block in this case. There is no anchoring required. Throwing in some perf pipe doesn't need engineering.
The OP is not up on this stuff or else he wouldn't have posted. You're just muddying the waters for him on what is a very simple installation that can be easily accomplished by anyone that can read the installation manual. It's labor intensive, but to save ten or fifteen thousand I think the OP will find the energy somewhere.
I would rather he do it right and do it once, rather than listen to your bad advice. There are plenty of "your" walls out there and they fail all the time.
Yes, anyone can ignore reality and just throw up a block wall. It won't last, though, and you'll get to do it again. Some people approach a situtaion and say "what is the least amount of effort I can put into this?" . That's you baby!
thats a excellent reason to just slope the ground1
I chalenge every one of you, tour your neighborhood! How many walls look like they were just built? If they look that way they are likely brand new:(
Most walls are bowed, sagging, cracking or just plain falling over:( Pittsburgh where I live has tons of hills and grade changes.
Most of those stack the block companies state how easy it is to rebuild:(
now go check your neighborhood, then go build that wall! It doesnt bother me at all!
ITS YOUR BACK AND YOUR WALLET:)
So enjoy!
I do agree walls can look nice when they are in good shape!
The trouble is they dont stay that way long:(
incidently my most troublesome wall is sitting right over a sewer line, so I cant build it a proper foundation. the wall cant be settling though, since the house was built in 1950..
this wall is beginning to bow, and will be the next one to go. moved here when I was 12 and projects were fun. tomorrow I turn 49:( I guess its better than the alternative!!!:)
I DONT want to be rebuilding walls at 75, so a permanent fix is the best.
You obviously think you have a better way of doing things, so please inform your reading audience what steps are necessary to insure the correct design and construction of a 30" high retaining wall. If you'd care to include any calculations and cost estimates based on your location, that would be wonderful.
If you've a strong back it shouldn't take long. I did one roughly these dimensions in two days:
day1 -- prep, get in the first course & make sure it's level day2 -- put up the wall
I don't remember the name of the system, but it's the stack kind with the lip in back, and filled with rock after each course. It would have taken about 1/2 the time had the company delivered the blocks where I was going to use them, not 100' away :)
I don't know what all the commotion about failing due to pressure is about -- these things have gaps between each brick, there's *never* going to be much pressure.
I don't remember what it cost, but materials were substantially below US$5000
Read the manufacturer's directions. The blocks vary in what they can do without engineering and the height begins below grade so if the block is 8 inch block and the first row goes underground, if they say you can build a
30 inch high wall without engineering they really mean the above grade portion will be 22 inches.
No clue how to design a wall, huh? Maybe you should have read your Pop's book. If you have a copy lying around, why don't you break it out and run some numbers for a 30" high wall.
If you don't want to do the math, pick up the phone and call an engineer friend. Ask them what they'd do to design a 2 1/2 foot tall wall. You'll probably have to repeat what you said after the laughter dies down.
Both will give you the same answer - you're making a big deal out of nothing. Your intentions are no doubt good, but in this instance the "engineer it" advice is not applicable.
Read the manufacturer's installation manual, follow the instructions. It really is that simple.
Last time you posted this comment I choose to ignore it but you're giving mis-information here.
Poorly design or construction walls can (& do) fall down or blow down, or shake down.
Well designed and constructed walls will (& do) last for YEARS.
When you say ALWAYS do you mean with their design life? With the owner's life? Or measured in geological time?
How long do you expect a wall to last?
IMO 50+ years is good enough for me.
My mom's house has a retaining wall (built in 1959) still standing. Also has a 4" block wall with 8" pilasters (not alowed by current code) but still standing after being exposed to 80+ mph wind gust.
Next time you consider a wall post to the group & we'll give you some pointers on making it last :)
The specifications are always very clear when it comes to the allowable dimensions. Almost invariably they will call out the allowable height above grade and then indicate how deep the wall must go below grade for that situation.
To give the OP something in his own neck of the woods:
I merely responded in kind to someone who chose to make personal insults directed at me. Meanwhile, the insulter gave poor advice that will not ultimately be helpful to the original poster when he has to rebuild his wall every 5 or 10 years. I pointed out right from the beginning that there was more to building a GOOD wall than just stacking some interlocking blocks. Rico duh jour didn't even think drainage was worth mentioning. Maybe he lives in the desert and there is little moisture and no freeze/thaw cycles to worry his pretty little head.
"Engineered" doesn't always mean hiring an engineer, or even doing any math, for that matter. I merely pointed out (correctly) that a good retaining wall needs to have proper drainage, and be anchored and tied properly.
Indeed? Allow me to refresh your selective memory:
Do you see anything in there that is insulting? Bad advice? Wrong? So then you piped up with this tidbit, "My wall will outlast your wall by many decades."
Besides being a huge assumption and wrong, that is insulting. A correction was necessary.
Either your reading comprehension is compromised or you just don't pay attention. The OP lives in Australia. How's that fit in with your theory?
My original advice to the OP: "Call a local masonry distributor and find out what sort of interlocking block they carry and how much they get for it. Then go to the manufacturer's web site and check it out in detail. For a low wall like that, they'll probably just instruct you to bury the first course of block to keep the wall from sliding. Then it's just stacking the block and backfilling."
Note the word probably. The manufacturer's web site will have all of the information the OP needs to build a 30" high wall.
Thanks for telling us that the engineering has already been done by the manufacturer for low height/load walls. Let me rephrase what you wrote, "Follow the manufacturer's instructions." That's obvious and you could have just said that.
If you're not equipped to do the math, compute the loads and design the solution, you have no business telling someone when engineering is needed because you simply don't know.
I have no problem telling people that they haven't supplied enough information and/or that the situation is more complex than their simple question, if that's the case. The original post was clear, the information adequate and the solution obvious. The OPs situation is not complicated, he could do the work himself if he's in half way decent shape, and the interlocking block manufacturer's installation instructions will guide him through the process.
I also have no problem pointing out a blowhard who makes mountains out of molehills. You, for instance.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.