Pouring foundations advise

redser7

I plan to build a raised bed along a garden wall. Dimensions 8m long x 0.5 m wide, 0.5 m deep. I'm making it with blocks so the foundation will be roughly 8m long x 8" wide x 4" deep.

Chances are I won't be able to get any help with this and time will be scarce so I'll be doing all the work myself over a period of a couple of months. Would it be possible to lay the foundations in sections? Say a few meters the first day, a few more the next day. If I place a board across the trench to break it up would that work out ok? Could it cause problems later?

I used an online calculator for the concrete and it looks like I'll need 0.16 cubic ms of concrete (roughly 2 x 25kgs bags of cement and 5 times that in ballast). Roughly how much work would you reckon that is for one person to mix and pour? I'm not afriad of hard work but have never done anything like this and don't want to end up having taken on a mission impossible? I know renting a mixer would be best but would mixing by hand in a wheel barrow be rediculous for this amount?

Thanks a lot for any advise!!

Buford T Justice

Dig the foundations and have them ready. Then hire a mini mixer and mix and lay the foundations in one day. It'll make life much easier for you. Doing the mixing by hand will be a pain in the neck

backboiler

I did a 4.5x0.3x0.15 strip (so that's 0.2 cu. m) by hand and it took a few hours (think it took 2 or 3 separate shovel sessions) but wasn't too stressful.
Your 0.16 cu. m will be roughly 300-400 kg and you have to turn it, what maybe 5 times? Plus you have to put it in the barrow and throw it in the hole.
You'll know you've been working when it's done, like.

redser7

Thanks for the replies

randy hickey

It's definitely doable to batch this up in one day Redser.However, having been that soldier, and also having the bills from the Chiroprator, I now use the mixer every time!

Carlow52

what blocks are u using for the 0.5 high with clay behind?
8" wide foundation is too narrow IMO

even if 4" on edge the min is 3 times = 12"

as stated get it all ready, cement, gravel and a barrel for water.

get a sheet of 8 by 4 and set mixer up on stand so as u can empty the mix straight into the foundation

redser7

Thanks again for all the replies. I was planning on a standard block laid on the side. Just reading around I saw that twice that width for the trench would be ok if the wall is to be under 2.5 feet high. It will only be 3 blocks high, one block half in the trench.
Now I'm wondering if a standard block would be too thin. Not just for strength but I'd like greater width so it has an edge you could sit on. So now I'm thinking about 9" cavity blocks. Would they be a good deal more expensive? Obviously they need a bigger foundation. Also, I guess you wouldn't have to fill these for such a low wall, just a capping, right?
Will defo rent a mixer.
Cheers!

Carlow52

9" cavity pain in the astec unless u very good brickie.
Go with 4" solids on flat, very easy to lay and cut, just use a 4" bolster chisel and a lump hammer.

2 get a good line on the 8m run do both corners and string a line

redser7

Thanks Carlow, advise much appreciated

randy hickey

Something just dawned on me.You could save yourself a lot of hassle and simply use railway sleepers.

redser7

Thanks but it's just not the look I'm after. Besides, for 8m length I think it would be a lot more expensive. Cheers

backboiler

I like looking at pictures of dirt and concrete*. They brighten up a thread no end. :P
Throw up a few if you get the chance. Before/during/after vibe.


* Other type of pictures also viewed.