ᐅ Thicken an L-shaped concrete block using formwork and additional concrete?

Hello,

Due to the slope at my terrace, I have a retaining wall that is 25cm (10 inches) thick. It was now too short for me, so I had an L-shaped concrete block added. The L-shaped block is 12.5cm (5 inches) thick. To create a straight edge when paving, I want to thicken the L-block with concrete.

So far, I have mostly found information about complete walls or base courses for fences, etc. Now I have a few questions.

- Do I need to build formwork for the full depth of the L-block? In other words, should the concrete pour extend into the ground to the same depth as the L-block? The total height is 1.30m (4 ft 3 in) minus the footing.
- Or can I put gravel up to about half a meter (1 ft 8 in) and only build formwork and pour concrete for the top 60cm (2 ft)?
- Do I need reinforcement? If yes, how much?
- Do I need to first pour a base layer before filling up to the full height?
- How important is frost protection for such a small project? Will the concrete crack otherwise?

I could hire a company for this, but I’m interested in doing something myself. I would appreciate any helpful tips.

To be honest, that will never lift!

Better cut the other wall to the same width or attach a cap on top.

tomtom79 schrieb:
To be honest, that will never lift!

Did you mean "hold"? Why not? Is it just a gut feeling or what would happen then?

I definitely won't be cutting into my €2000 (approx. $2170) retaining wall.

I still don’t understand how a cap would help when paving against it, but it gave me another idea.

For example, a stainless steel sheet bent into a U-shape that I can slip over the wall from above. On the side facing the paved surface, I would let the sheet hang down longer so the paving can be installed against it.
This would create a gap between the sheet and the L-shaped stone in the area of the L-stone. I could possibly fill that gap later.

Alternatively, instead of formwork, you could "glue" an entire curb stone of the required thickness in front (already concreted in). There are curbstones all around the paving anyway.
Then from above, you could place the sheet again to cover the patchwork so it’s not visible.

Hello Kaspatoo

I have had good experience with "repair concrete." Regular concrete will not work for this.

Steven

Is repair concrete not mainly intended for cracks and broken corners, rather than for casting an entire block?
Why wouldn’t regular concrete work? What exactly would cause problems?

Hello Kaspatoo

Repair concrete cures harder than "normal" concrete. If you apply concrete too thinly, it will crumble sooner or later.
Repair concrete would (probably) hold.
Personally, I wouldn’t do that. I would thicken it in another way somehow. Possibly a curb stone of suitable thickness.

Steven