Small Retaining Wall for Garden

[Damian30]

Hi,

My garden slopes into a corner and I am looking to build a small retaining wall so that I can get a more level ground.

The wall will only be 20 foot in length and a maximum height of about 2 foot (this will obviously reduce as I will need to step the footings as they cut into the slope).

I want the wall to be a double skin of frost resistent bricks, rather than pavers on their edges, etc. I am trying to get a local brickie to do the wall but want to get as much prep done as possible, including doing the footings.

Please can anyone advise on what depth the footing perhaps need to be below ground level and what width based on two skins of bricks. Also, what sort of mortar mix would be best for the footings?

Any advice would be very much appreciated.

Thanks and best wishes,

Damian

 

[nstreet]

Search the forums for 'walls', lots of previous posts, probably why there are no replies as yet.

First off your footings need to be concrete not mortar, 10 shovels of ballast to 1/2 bag of cement should be ok.

Personally for the skin that you won't see I would use dense concrete blocks, they build quicker and are cheaper than expensive bricks.

 

[tawelfryn]

Dig down 600mm below your lowest ground level, as for width of foundation, dig 300mm wider than what your wall will beat the bottom, ie one brick thick wall, is 225mm, 225 + 300 = 525mm, this leaves 150mm of concrete either side of wall. Lay 150mm thick concrete foundation. Might be worth considering making the wall thicker than 225mm at the bottom for at least half the height, if its holding a lot of earth back, maybe blocks laid flat, with ties left out for brickwork, then go to to blocks laid upright half way up the wall, making 9" at the top or 225mm. I agree with nstreet, using blocks this way will save significantly on bricks.
Oh and I would make the concrete to a ratio of 4 chippings, 2 sand 1 cement, and build the wall out of a mortar mix of 4 sand 1 cement. Use buckets for gauging into the mixer, and you will always get the right mix

 

[Damian30]

Hi,

Thanks for the replies.

Having thought about it further, for the highest part of the wall, I was intending to dig 600mm deep and install a 450mm footing leaving a gap 150mm below ground level. Where the wall cuts into the slope and the number of brick courses reduces to 2 - 3, I was going to lay a shallower footing (perhaps 150mm thick)? Any views?

Both skins of the wall won't be seen at present because of the boundary fence but I was still planning to use a skin of engineering bricks and then the concrete blocks on the 'inside' skin. I probably could have got away with 'flags on edge' but thought the wall may be a better solution.

In terms of the concrete blocks, will any suffice or is there a particularly suitable block? Also, do they come in the same size as the bricks or does it not matter that they may be larger. Was thinking more about tying the 2 skins together. By the way, can anyone recommend any ties for doing this (and where I can get them from)?

Many thanks for your advice so far.

Best wishes,

Damian

 

[Thermo]

what exactly is the wall going to be holding back? loose soil, virgin chalk etc?

 

[Damian30]

Thermo,

The wall will be holding back soil & lawn (and as the land drain runs very close parallel with the footings, there will be some loose pebbles/gravel below the soil).

Thanks,

Damian