How to replace two Colorbond posts cemented in a concrete retainer wall?

[Ask_Itee]

Some years ago a 30ft Palm tree in our pool yard was blown over in a storm damaging our colorbond fence.  Two colorbond posts were damaged (bent but still functional) and I'd like to replace them.  The fence shares the pool enclosure and rear reserve.

Because of our location, we have been told by the council we'd need to erect a pool safety fence around the work while the retainer wall was cut, the posts replaced and situated, and the concrete retainer wall reconstructed in that section.  A contractor said it would be about 3 days work.

I have figured out a workaround for the fencing requirement, but this is the only method I can come up with for replacing the posts.

The aim would be to:

• drill out the concrete holding the posts in place with a long masonry bit down to a depth of 300mm
• Remove the damaged post (colapse it onto itself)
• Fit a new post and position
• Concrete the hole where the post is placed
• rejoin rails etc to the new post/ss

Practical, do-able, dreaming?

[MitchellMc]

Could you take a picture for us @Ask_Itee? 

From your description, I can't really see a need for the retaining wall to be deconstructed, nor why that would be the best plan of attack. I think you're bang on the money with breaking the post footer from above, digging it out and then concreting in your new posts. I'd imagine this could be done in one day or two at most as a D.I.Y. project.

My only suggestion would be to pick up a budget-friendly rotary hammer drill so you can drill through the footer in several locations and then switch it to chisel mode to break up the footer. Remember to wear your PPE gear, including safety glasses, gloves, and enclosed footwear.

Please let me know if you have further questions.

Mitchell

[Ask_Itee]

Thanks MitchellMc,

That I do have - long masonry bits (6mm, 12mm,, 18mm) and a two good hammer drills.

yes to elaborate on my plan.

• Remove top rail and panels either side of post
  • Pop out the southern bottom rail and lower it back down but inside the fence line and chocked to the same height it would sit if still attached to the post.  This will hopefully allow the fence to keep doing its job while I toil away
    
• Refit top panels and top rail so that the top rail too sits inside the fence line - put a holding screw in both rails
• Start drilling out the inside of the posts on one side down as far as I can go
• Repeat for the northern side of post.

I am trying to think of Plan B if the retainer wall and posts go down further than 300mm and I can't think of a way to shear/cut the posts off as low as possible.  It would be awesome if I get to 300mm depth and have passed or be very near the depth of the post embedded in the retainer wall, but if Murphy's Law applies to the job, they'll be 350mm down to the bottom.

Any ideas anyone? I could go longer drills I suppose!

Thanks for the PPE reminder - must check if I need anything

[EricL]

Hello @Ask_Itee 

It sounds like a good plan; my only other recommendation is to have a look at getting a Cyclone 1650 x 25mm Hex Fencing Bar just in case you need to go deeper to break up the concrete footing. I also propose looking at the Saxon 170cm Black T Steel Fence Post as a temporary post while you break the footing apart. My only other suggestion is to check the weather and make sure that you've got a few sunny days ahead so that your post hole will not fill up with rainwater. 

Please keep safety in mind, make sure everyone is informed, even though you are working in an open area friends and family members might lean into the unsupported fence panels. As @MitchellMc mentioned please make sure to wear proper safety equipment while digging and breaking apart the concrete footing.

Please keep us updated with your progress, we look forward to the start of your fencing project.

If you need further assistance, please let us know.

Eric