what to do for the gaps on outdoor stairs

[rajl]

Hi there, any suggestions on what can be done to fix these gaps. It appears the deck and stairs were built separately and they seem to be coming apart. 

 

 

 

[EricL]

Hello @rajl 

Welcome to the Bunnings Workshop community. It's sensational to have you join us and thanks for sharing your question about your outdoor steps.

I highly suspect that water has entered the foundation of your steps and has caused it to shift. This is why there a gap has appeared near where the steps meet. I don't know if you have a timber or concrete base underneath those tiles, but in order to repair them the foundation must be addressed so that it can be returned to its original position. I can see from your pictures that a filler was placed between the gaps. 

It is possible to put another type of filler between the gap, but if the underlying cause is not addressed the filler will fail again as the base of the stairs will keep shifting. If you are not yet prepared to have it repaired properly, I suggest filling the gap with Moroday 15mm x 5m White Gap Filler and covering the top of the filler rod with Sika 300ml Concrete Grey Sikaflex 11FC Purform.

If you have any other questions we can help with, please let us know.

Eric

[rajl]

Hi Eric,

thank you so much for your advice.

Will check if there is underlying base. However, any suggestions on how the foundation can be fixed? Or would it work if we build a timber structure on top of it ? 

Thank you

[JacobZ]

Hi @rajl,

Unfortunately, any kind of "cover-up" repair would not fix the underlying issue.

If you were to build a timber structure over the top, the stairs would not stop subsiding. If the timber structure relied on the stairs for support, then the timber structure would also subside over time. 

I see two options, both of which aren't exactly simple.

The first is to remove the stairs and rebuild them, ensuring the substrate is sufficiently compacted and retained to prevent erosion once the stairs are reinstated. This is the best option if you are looking to rectify the underlying issue, which is erosion of your substrate.

The second option is to contact a company that specialises in slab jacking or concrete subsidence issues. They may be able to pump specialty expanding foam into the gap to raise the stairs back to their original position and support the stairs moving forward. I can't say for certain this is an option in your situation, but it is worth exploring this option.

Allow me to tag @Dave-1 and @Nailbag for their thoughts.

Let me know if you have any further questions.

Jacob

[Dave-1]

Good Evening @rajl 

My first question is - How long has it taken for the difference in height to be noticable?

If its taken years then it will probarly keep on happening so you will have to plan something down the track to rectify the issue. But you have time to plan

If its happend fast then you need to find the reason why and rectify it now.

I have two things that you could do to make it look ok for now but depending on how fast the movement is happening it will be a hard call on which way to go.

A - Use a right angled metal bar Metal Mate 50 x 25 x 1.6mm 1M Aluminium Unequal Angle - 1m You put the short side on the step and the high side on the rise. You glue the base down. This will allow the seperation to continue but hide it.

B - If you can lay your hands on the same tiles (buy extra for sure for when the steps gets fixed permantly) then you could remove those three rise tiles and redo to suit that back plane. This is presuming the movement has stopped.

I wouldnt be building anything over the steps until the settlement has been sorted.

Dave