Front garden wall foundation onto concrete

[officerlog]

Hi all

I would like to build a brick wall between the front garden of a semi detached house. The footing is existing concrete which is on a slight slope down away from the house. How would I ensure it is level to build the wall? Is there a specific way to use formwork ontop of concrete? Trying to add a picture but keep getting a security error. Any ideas for the wall welcome. Thanks

 

[Tigercubrider]

I suspect that you can't just start a wall on an existing concrete slab.
It would be easier to cut a line, remove the edge of the slab, dig a trench and cast a new foundation.
Using pegs and string will get you a horizontal level. or some reference points and a kind of dipstick like T shape from wood.
Wet concrete wants to be close to flat anyway.

I think that a wall just built on a slab will fall over?
not a bricky

 

[officerlog]

Thanks Tigercubrider. it's actually some rather unsightly poured concrete rather than a concrete slab. Hopefully the picture works now. I have marked in black where i want the wall to go. I will lay paving on the other parts and create a victorian pathway leading up to the steps.

 

[Tigercubrider]

again, no bricky but as you have a pillar. and it's not facing onto the pavement (vandals kicking walls over) you might get away with wall starter kits at each end?
Hopefully someone will be along in a bit who knows more

 

[^woody^]

You would level the first course of bricks if possible - via the joints or cut bricks.

How much out of level is it, over what distance?

 

[officerlog]

its about 150cm and a gentle slope so first course will be unlevel unless i manage to either build up the foundation on the end sloping down away from the house or dig the existing concrete the other side in order to level it. Tricky one!

 

[^woody^]

That's doable as mentioned above, especially as you say you will be laying paving which will hide the bottom of the wall.

Start at the low end with a big joint and lay that course which will have a tight or no joint at the other end.

There's threads about this in more detail regarding uneven foundations.

 

[johnny2007]

If the slope is too steep, gain level in 2 courses.
It's fine to build on that concrete, unless it's only an inch thick.
Use wall starters on either ends.
And clean the concrete before you start lying bricks, brick cleaner will do the job in seconds, otherwise jetwash or bleach and hard brush.

 

[officerlog]

Thanks everyone!
So in summary, give the concrete a good clean, find the level and start at the low end where I build up the joint and have more flexibility as it will be hidden by paving slabs. Oh and use wall starters.

 

[^woody^]

Wall starters are a waste of time and money. Use a couple of fishtail ties at each end.

 

[johnny2007]

Wall starters are a waste of time and money. Use a couple of fishtail ties at each end.

I second this, for a small wall it will be more than sufficient.