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bigviclbi
07-05-2005, 09:41 PM
Guys I have a question. I have a customer with a slightly sloping backyard on a budget. Instead of using more blocks would it be possible to use more base to make a flat base from the house to back wall at the height the first buried block by the house is , then backfill behind the blocks that would have had to been a couple inches lower? I don't know if I explained this well but if anyone understands me tell me why I can't do this.

MarcusLndscp
07-06-2005, 12:01 AM
Well, I tried figuring out what you meant a couple times but a little more clarification would be great. Are you asking if the end of the wall down slope can sit higher than existijng grade and then you fill around it to support it?

bigviclbi
07-06-2005, 02:07 AM
Yes, because say you dig down into existing soil like I've done countless times. Why is that soil any more stable than if I backfill with aggragate or soil and tamp that soil maybe not with a vibratory which might be too powerful but maybe with a hand tamper. I usually dig down but can't honestly say why this wouldn't work. It really never even entered my mind until today. Give me some feedback on why it wouldn't work. Thanks in advance. Also the slope is 8 inches over 13 feet.

MarcusLndscp
07-06-2005, 09:19 PM
My only concern would be that you would certainly have to make your base wide enough to support your wall. If you made it too narrow it would be my belief that it would slump or shift quite easy thus making your wall do the same. I would compact the heck out of the gravel base and the sides of it and then cover with whatever material you need to plant, put in a lawn, whatever. When you dig down and add base remember that you are typically digging in soils that have been allowed to settle overtime unless it's new construction areas. When you add your base material it is supported completely on all 4 sides by soils that are for the most part done settling proving your base with more support. It sounds like your job is quite small is their cost difference so much less that they are concerned with burying 8" of block 13' long? Good luck

bigviclbi
07-06-2005, 10:33 PM
Not so much price but was just wondering about the process and if anyone did anything like this before. I actually would have a wide base since the whole thing is a raised patio I would just run the aggragate from the house two feet past the wall, lay my bottom block then backfill. Being new construction I feel that my tamping the backfill would be comparable to the virgin soil. Thanks for the input not sure if I am going to try it or not.

Grounds Control
07-07-2005, 04:41 PM
you want to remove any organic matter under the base of the wall. It's not stable under loads and water and will shift or sag, even with your base on top. obviously, the more base and less organic matter would have less effect and vice versa.

also, you want to bury at least the first coarse of block to help keep the wall in place once under load.

YardPro
07-12-2005, 06:13 PM
your vib tamp only compacts only a few inches.

it is not comparable to virgin soils.

bigviclbi
07-12-2005, 07:02 PM
Yardpro, if I am digging down six inches what would be the differnce if i backfilled with aggragate and tamped it? I think that would be stronger than soil that was just graded in the last six months.