How to fix leaning masonry fence?

[Martinholden]

It has been identified by 2 independent structural engineers that our masonry fence is leaning. We are in an owners corporation. The fence is approx 160cm in height and runs along a common walkway. One engineer has stated that it is significantly leaning (41mm per metre) and is a hazard as it at risk of falling over.It also has significant step cracks.The other engineer has identified that it is leaning but is of moderate concern and should be supported or replaced within a 3 year time frame. Who do we believe? Both reports state that large trees planted too close to the building, tree roots are the likely cause. 

 

 

[AlanM52]

Hi @Martinholden,

I would get another opinion from a building inspector.

Cheers

[JacobZ]

Hi @Martinholden,

Welcome to the Bunnings Workshop community, it is fantastic to have you with us.

41mm of lean per metre is not insignificant. While it may still be relatively stable, there will be a tipping point where it will no longer be stable. Considering that the cause has been identified as tree roots, which will inherently grow larger over time, I would be concerned about the potential for that tipping point to creep up faster than anticipated.

In my personal opinion, considering the shared liability for any issues that could come from the wall collapsing, it is likely in your best interest to err on the side of caution and have it fixed sooner rather than later. 

If you couldn't come to a consensus with the other owners, then it is probably worth getting a third opinion from a building inspector so that you have a 2 to 1 situation in terms of opinions.

Allow me to tag @Noyade, @Nailbag and @R4addZ for their thoughts.

Jacob

[Martinholden]

Thanks Jacob. I agree with you and tend to side with the Structural Engineer's report that states that they are significantly leaning and need to be removed. Aerial shots taken by this engineer over a 10 year period shows massive tree canopy growth. This engineer has also recommended tree removal following inspection of infrastructure plumbing. This Structural Engineer has additional qualifications, as he is also a forensic geotechnical Structural engineer. I have attached further comments from his report.

The other structural engineer recommends either tree root barriers or tree removal. These are very old trees and my understanding is that tree root barriers are not that effective on old well established trees. He also recommends a time frame of upto 3 years to address trees and leaning fence.  This to me is too long a time frame which could lead to further structural issues. 

 

 

[JacobZ]

Hi @Martinholden,

Considering the qualifications and quality of the report that this structural engineer has provided, I would be taking them seriously and making a case to the other body corporate members that this is something that should be addressed immediately.

It sounds like there might be other issues that will also need to be addressed, so it is probably best to get the most immediate one out of the way right now.

Jacob

[Nailbag]

Hi @Martinholden 

You could get a 3rd opinion, but looking at the crack running full height, the wall right now is structurally compromised. And if the trees are still growing, then increasing pressure on the wall to continue is obvious. A window of 3yrs by the 2nd engineer is essentially a best guess as far as the further end of the timeline. So in other words, he is essentially also stating it could collapse at anytime from now on.

I would treat it as a priority and have the works completed under a controlled environment and not one after a wall collapse.

Nailbag

[Martinholden]

Thanks for all responses. I do question the integrity of the 2nd engineer's report. Of concern is the time frames but also comments about the leaning fence. Note that he was also given the 1st Structural Engineer's report (not sure why this was done as his report should have been independent). As per below extract from his report he stated "that it is inappropriate to apply today's tolerance to existing structures to say whether (fence) should be removed or similar". To me that does not make any sense at all.