Mass Concrete Wall Estimate

brickland

Hi All,

Despite my username I have no background in building walls!!

I am looking for a rough cost figure for building the following wall on a farm

100m long
3m high
150mm wide
No foundations in place, my guess for a foundation would be 100m x 400mm w x 250mm deep but only a guess.

I have estimated the following myself but have no idea of costs
- concrete for wall 43m3
- concrete for foundation 10m3
- Blinding for foundation 1 load of 804
- digging foundation 2 days for track machine

Here are the parts I have no idea of
- shuttering costs
- quantity of steel for wall
- quantity of steel for footing
- scaffolding or access to the top seen as it is 3m high

I have thrown a rough guess of around €25-30K all included but I am wondering now am I miles out. And it has to be mass concrete, not block.

Thanks all

Gumbo

150mm mass concrete wall and only 250mm deep foundation. I don’t think so.
I think you need at least 300-350mm deep foundations that are reinforced.

You also need to tie the reinforcement in the wall to the foundation so kickers and bar schedule required.

delfagio

brickland wrote:

100m long 3m high 150mm wide No foundations in place, my guess for a foundation would be 100m x 400mm w x 250mm deep but only a guess.

That's a big wall. What's the wall required for? Is it to retain ground on one side or just acting as a boundary of some sort?

I agree with previous post, the footing would need to be at least 350mm deep, 400mm wide would probably be too narrow to withstand overturning moments given the fact that the wall is 3m high. Plus without knowing the soil or ground properties you don't want the wall to begin to sink into the ground. Mass concrete is approx 2tonne per m3,

You really need a structural engineer to design this, taking into account wind loading etc. The structural engineer would design the footing, wall, steel reinforcement, and spec the steel sizing and spacing.

brickland wrote:

Here are the parts I have no idea of - shuttering costs - quantity of steel for wall - quantity of steel for footing - scaffolding or access to the top seen as it is 3m high

The footing may need a kicker type construction with starter bars to tie the wall to the foundation. The structural engineer can advise of this.

You should use a retarder agent on the top of the kicker immediately after the concrete is poured. Then power hose the top the next day to provide a surface the wall can bond to.

Shuttering wouldn't be too expensive, sheets of ply can be cut to suit concrete pours. The sheets should be oiled to prevent concrete sticking to the ply. This also allows you to reuse the shuttering again and again

brickland

Thanks all, great feedback.

Its not a load bearing wall other than its own weight and wind. Its advice for a friend who wants to build a boundary wall so I’m only looking for someone to fire a ballpark number at it. I won’t be doing or paying for the job. Is €25-30K realistic?

I guess I’m looking for someone to tell me it is very dear compared to block on the flat with piers or even a lower post and rail job which I already know but I can’t get that point across to my friend without some sort of number for this wall. He has his mind set on this for some reason.

kieran.

Once you get a engineer on board, I think the dimensions of the wall will differ a lot for yours above. A continous 3m high freestanding wall is a lot of wall this will require a lot wider foundations than 450x250mm.

40k would be closer to the mark on costs in my opinion.

Have you explored any other/precast options.

my3cents

Is a 3m high wall OK to build on a boundary without planning permission?

brickland

Again thanks for the feedback. Re: kieran. I will go with €40-45K that might at least get him to change his mind.

It is only advice for a friend so he can explore whatever he wants with an engineer or planning office. It is currently not a boundary so I’ve no idea regarding what planning is applicable and he can deal with that himself.

theparish

1.engineeer
2.quantity surveyor
3.planning
4.builder

brickland

theparish wrote: »

1.engineeer
2.quantity surveyor
3.planning
4.builder

I am an engineer just not a civil or structural so I know that much thanks.

I’ve enough feedback for now, thanks all.