Garden wall foundations - Building Help

[tntcoda]

Hey,

Need some help planning the foundations of a fairly large garden wall, its 23meters long, 2 bricks thick. My plan is to have 40cm deep foundations (35cm concrete + 5cm hardcore base). It will be about 6 bricks tall, maybe more (will decide later).

Ive just used a laser thing to check the height difference at each end, and the right end of the wall is ~ 13.5cm lower ground than the left, so ive decided to use steps to account for this, by splitting the 23m into 3x7.6cm level steps, which im hoping is the correct thing to do?

This is my current plan:


The problem im having is i dont know how deep each steps need to be? In the diagram i have put the top of each step at the bottom of the previous one, but this is probably way to deep to account for a 13.5cm slope

Can anyone give me some pointers on how deep the steps need to be to keep everything nice and level? (I have very little building experience!)

Thanks,

Jack

 

[roberta1000]

I should think you could build a house on a foundation like that - for half a dozen courses you'd probably get away just fine with about 75mm of concrete and not bother about the hardcore unless you feel you must.

Your wall will look funny if the courses of bricks don't line up (even if you have spacers in it) so each step needs to be a single brick roughly as you've shown. This means that you need to step the footings by the thickness of a brick plus the mortar thickness between the courses. You could start digging the footings at the low end so that the bottom course is about flush with ground level or wherever you want it (remember there will be a bottom mortar joint) then dig along until you've got enough cover for your brick and joint and step the footings up etc. Ofg course you don't need to put the top steps in line with the steps in the footings if you'd prefer them somewhere else.

 

[Delinquent]

as above, you need to step in whole brick depths. Bricky doing the wall at our place just made each step a multiple of 75mm (standard brick plus mortar).

To ensure it works, start at the bottom, dig your footings for that bit, then step up the next footings whatever multiple of 75mm will ensure the next step won't have founds showing above soil, repeat for next step.

 

[noseall]

you will need to overlap each step of concrete by 200mm or so.

lay the concrete 150mm thick on good ground.

as stated, each step depth must be divisible by the same increments as the masonry being laid.