How to increase width of stairway in retaining wall?

[Brycem]

Hi was wondering how complicated (or simple)it would be to increase the width of the stairway that is within the retaining wall?

Would be looking at increasing the size by 3 bricks width on each side.

 Is it's as simple as cutting out the bricks and relaying that section with bricks as stairs ?

  

    

[AlanM52]

Hi @Brycem,

Sorry to say that is not a DIY project, the whole thing will need to be demolished/rebuilt and you will likely need engineering input for council approval - and a bricklayer..

Cheers

[EricL]

Hi @Brycem,

Thank you for sharing your question about increasing the width of your stairway. 

It's great that you've received excellent advice from @AlanM52. I agree with Alan's recommendation, this is not a simple project and would recommend engaging the services of a structural engineer. General speaking, the soil would need to be dug back, and the retaining wall would need to be disassembled. A proper foundation would need to be designed and built, if it is not properly made there is the possibility that it will collapse.

If you need further assistance, please let us know.

Eric

[Brycem]

This isn't accurate, you don't need council approval to change this in my area, will also point out I am asking from a diy respective while I have had plenty of quotes the Bunnings team have given a more accurate assessment of what to do whilst you are way off - please don't response to posts from now on

[JacobZ]

Hi @Brycem,

When retaining walls are above 1m tall, they often require engineering and council approval. I count 10 courses, and knowing a standard house brick is around 80mm tall, this would put you under this limit.

Contrary to the others, as your wall doesn't appear to be over this height, I don't think you need council approval or an engineer, but being cautious and double-checking is still probably worthwhile to ensure you are doing your due diligence. Realistically, you would be reducing the amount of pressure on the back of the wall as you would be removing material pushing against it, so I think it is achievable D.I.Y., but you would need to ensure you take precautions to ensure it doesn't collapse.

What you are proposing is likely achievable, but like Eric mentioned, you would need to excavate the soil from behind the wall, install temporary shuttering to hold back the soil while the work is done, assess and likely modify the foundation so that it lines up with the new return walls, then rebuild these return walls, tying them in with the existing wall by knitting the bricks into them like I imagine they are now, before backfilling and reinstating everything. House brick retaining walls are usually just built on basic concrete strip footings, so you could likely pour one in place with the soil around it excavated.

It wouldn't be as simple as removing the bricks and moving them over, but I don't think it's unachievable.

Let me know what you think. Happy to offer further advice if necessary.

Jacob

[Brycem]

Thanks Jacob, want to make it know  the above was not in response to Eric, apologies if that wasn't clear!

Correct the highest point of the wall is 900mm while the rest is well below. Be good to know.the following:

- should I excavate behind the sections I want to cut out prior

- do I need to also bring the wall in at 90 degrees angle still or can I just do it straight across with the steps coming in

- any other steps I have missed.

Appreciate the help

[JacobZ]

Hi @Brycem,

Yes, you would have to excavate before cutting things out, as you need to take the pressure off the wall before altering it. If you just cut it, the soil could shift, which would mean a whole lot of cleanup and potentially damage to things.

You would need to replace the 90-degree return walls, as they are also retaining soil up to the height of the front retaining wall. The stairs would not retain the soil up to this height.

Let me know if you have any further questions.

Jacob