retaining garden wall

[ngater]

Hi

Quick bit of advice for a beginner if anyone can spare the time.

I am building a small retaining wall in the garden, finished height 0.7m by roughly 2.5m wide. Soil is clay so I have dug down for foundations 0.40m deep by 0.7m wide, base of foundations is on solid clay. I have a couple of questions which I am unsure on.

1. Am I better using concrete blocks & then rendering or engineering bricks (using Garden wall bond)?

2. Will I need to build a pier halfway along the wall for additional support. I was planning on piers on both corners for added strength.

Have looked on www.pavingexpert.com but couldn't find any answers.

Thanks in advance for your help!

 

[noseall]

lay the concrete in the trench min 200mm thick.
garden wall plus rendering equals high maintenance. i would go for giscols in the main wall with solid blue engineering bricks laid flat on a tiled crease for a coping.
if its only 2500mm then two 440mm square piers at each and will be plenty.
as for bond, feel free to use your imagination, as its not particularly high.

 

[ngater]

thanks for your advice .... think I will go for the brick option, last thing I need is high maintenance.

 

[ngater]

just to add a further question, I am assuming you would suggest using a double skin rather than a single stretcher bond wall?

 

[noseall]

any retaining wall should be built with twin skin as a bare minimum.

 

[ngater]

thanks, thought as much but wanted to check before I bought the bricks

 

[Static]

Asuming your putting the wall in the middle of the garden with no house just behind/infront of it. 700mm from lower level to upper level?
I would advise making the footing 800mm wide, using engineering bricks (dont use blocks for free standing retaining wall) and if you want a handrail on upper side place it in small concrete pockets independant to the wall.
On the other hand if you arent too fussed about the wall ignore the above

 

[ngater]

thanks, settled on engineering bricks now. Foundations are already down at 700mm - hopefully that will suffice. Thanks for the further advice.

 

[Static]

With foundations already down possition the wall slightly closer to the lower retained side of the foundation, to put more soil load on the footing (ie about 200mm from edge of footing measured from lower side). My concern is with the wall sliding forward so the added weight from soil will help.

 

[ngater]

thanks .... will do. Hoping to start this weekend weather permitting.

 

[ngater]

OK ... still not started yet & budget is looking like changing my plans. If I were to use dense concrete blocks what strength would I need? Is 7N overkill?

Looking at using 140mm ones at the moment.

 

[Static]

A 140mm thick wall of blocks? still retaining 700mm?

Assuming you intend to lay the wall 280mm wide you will need to make the blocks are suitable for foundations and are at least 7N/mm2. Also youll need more movement joints (every 6m). And above all youll need a mate to lift each block with you as they will weigh something like 25kg each unless you dont mind a bad back for a few years.

You would be better off sticking with the original plan.

 

[ngater]

static, thanks - when you put it like that, it seems far more sense to spend the extra couple of hundred quid and do it properly.