Repairing concrete coping stone Featured

A photo or two would save an awful lot of questions and answers.

How is the best way to attach a photo as this is not something I have done? I know how to give an individual access to my Google drive but how do I allow access to an entire newsgroup in a safe way?

Upload an image to a photo sharing site like:

You would set the file share permission to enable view access to "anyone with a link". Then post the link here.

Or stick it on the wiki:

Sorry, I don't really want to hand out my personal details or sign up for an account so I'll give it a miss thanks.

You don't need to.

1. Click on link above
2. Click 'start uploading'
3. Select file from your computer
4. Click 'upload'
5. Copy the URL for your post

Here's my link to a random image lying around on my computer:

Very poor internet trolling here. You could have posted a G***se or lemonparty image and got loads of clicks :-)

On 01 Apr 2025 15:25:12 +0100 (BST), Theo <theom+ snipped-for-privacy@chiark.greenend.org.uk> wrote: [snip]

Thanks for your patience and assistance. Here it is:

Looks like a fix would be easy - however making it invisible difficult.

Assuming replacing the whole coping stone is not an option, then clamp a smooth timber batten across the gap at the edge of the stone, and fill with a mortar mix, then rule that off flush with the top surface of the stone. When dry, remove the batten and a bit of sanding to smooth and blend in.

The difficult bit will be getting a close colour match. It looks like a fairly "strong" mix (i.e. fairly low sand to cement ratio), and probably with a light coloured sand. You would probably need to do some small test mixes and let them dry to asses the colour before doing the actual repair.

(or failing that, paint the stones with masonry paint when done!)

Consider when clamping the wood across the gap that later you will have to tap it lightly with a hammer to vibrate the mortar mix to remove the air. Failure to do this will probably result in air bubbles in the finished surface. The clamping of the wood needs to be robust.

I would replace and refit assuming this is a brand new coping stone and hasn't weathered. Finding the source might be tricky but armed with the old one a builders merchant might be able to match the source.

Otherwise any filling material will be fairly obvious to most where it's difficult to match both colour and texture. This might be a starting point though I have never used the stuff.

Thanks very much. In an unexpected development, the guy who was supposed to be doing the job (who was not replying to texts or calls) has now turned up. Reassuringly, he said the same as you. Apparently the sand he has is much darker. He was waiting to speak to me to recommend ... a new coping stone.