How to repair holes in limestone retaining wall blocks?

[jose2]

Hi my fence line retaining wall and surrounding blocks are aged and weathered and started to deteriorate. Perforated holes throughout blocks, I am looking at multipurpose filler (PARFIX) to do the job  or is it better for a longer term solution to use mortar and sand?

[EricL]

Hello @jose2 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your limestone wall blocks.

It appears that severe water penetration from the other side has eaten away at the internal structure of the limestone. Technically a waterproof sealer such as Gripset Betta 1L Waterproofing Membrane Bitumen Rubber should have been placed on the soil facing side of the limestone. This would have stopped water from coming through and prevent the deterioration of the limestone. In this particular instance, I suggest replacing the badly damaged limestone with a new set and making sure that it is waterproofed before installing it.

Although patching it with mortar may be possible, I'm not sure how long this type of repair will last especially if the water ingress into the limestone is already severe.

Let me call on our experienced members @Dave-1 and @Nailbag for their recommendations.

If you need further assistance, please let us know.

Eric

[Dave-1]

Good Evening @jose2

I was about to suggest to why not mortar the brickwork, it has enough holes so the mortar would bond I figured. Then i read @EricL 's comments and suggestion. Id say follow his advice more so. Doing a "coverup" (Which is what I was going to suggest) of the brickwork without fixing the start of the issue will mean that you will be back at a problem state sooner.

Are all the blocks along your retaining wall/fenceline like that? If the soil side was able to be dug out and as @EricL suggested painted with a waterproofing agent, backfilled and then you could mortar. Long steps I know but it saves you from repeating the fix down the track.

Dave

[Nailbag]

Hi @jose2 

I would agree with both @EricL and @Dave-1 and go for a more structurally permanent solution over a cosmetic one. Having said that I am not sure as to what product would be best other than something that was flexible once the gaps were filled with a product like Sika pro masonry.  Perhaps something like this acrylic flexible render might work but you would need to check with the manufacturer if it was suitable. @EricL may be able to assist?

Nailbag

[jose2]

Thank you everyone for your advice an assistance, unfortunately I do not have access to the soil side as my neighbour has concreted a path along the fence line. Given the information provided I'll  go with the mortar patch repair  to reduce the eye sour in the yard and see how long it last. Thanks again.