building a block wall for the first time

[rhurbarb]

Hi Im about to build a block wall in the back of my garden ..It is 27ft long and i need it to be 6ft high...Ive used a online estimate program which said i need 180 blocks approx...How deep would i need to do the foundations and how wide ,will i need pillars and drainage ,and would i use 100mm blocks . It will be supporting a mound of mud ,appreciate any help ..Thanks guys ..Rhurbarb

 

[^woody^]

Is it holding 6' of mud?

 

[r896neo]

Even if it was free standing 6ft is too high for a 4'' wall.

As woody says how much is it retaining.

 

[RonnyRaygun]

A six foot retaining wall needs to be designed by an engineer.

If you decide to wing it, it would need to be at least 450mm thick at the base and something like a 1m wide foundation, if not more.

But you really shouldn't wing it with a six foot wall. What I'm saying is that 180 blocks will be nowhere near enough.

 

[rhurbarb]

The earths about 4ft high..its currently being held back by tavistock rock which is stacked on top of each other without any cement bonding it together...doesnt seem to be not much load against the original wall.
I thought a 6ft high wall with a small fence on top would block out the dogwalkers etc from the park .Thanks for the quick replies..Rhurbarb

 

[tony1851]

Regardless of whether or not it's acting as a retaining wall, 6ft is still far too high for a 100 block wall, even if most of it is not showing above the top of the wall to the rear.
At 27ft long, you might need to consider a movement joint, though it's on the borderline.

 

[rhurbarb]

Ok Thanks Tony .is there a step by step guide or a video i can use as a reference for this? ..Thanks guys

 

[tony1851]

is there a step by step guide or a video i can use as a reference for this? .

You need to be careful on this as it's not just a case of following a few diagrams.
Even if the wall is partly in front of another wall, it will still be exposed at the top and will be subject to wind pressure (and possibly suction). Wind pressure acting on, say, the upper exposed 2 ft of the wall could be enough to topple it because of the leverage.
Personally I wouldn't consider a 4" thick block wall viable - it's far too slender.
Although it would be an extra expense, I would be inclined, as RR suggested above, to have a word with an engineer.
Even if you just phoned a local engineer, I'm sure they would explain to you the issues and where you might come unstuck if not careful.

 

[rhurbarb]

Thanks Tony thats very interesting points you brought up there .I will ring the engineer ...Thanks mate ..Rhurbarb