How to refill path to leave isolation joint

boardtc

We cut my footpath outside the back door to run electricity to the patio, see below for before and after. I want to fill it in but put back in the isolation joint - which I think is what the gap is called. Is there a mould or something you use to achieve that gap joint?

mickdw

Those markings are via trowel and groover.

Edging trowel for the edge of path and the groover for doing the joints.

Search marshalltown concrete groover on amazon or the likes

listermint

Don't bother with a joint it's not needed in that size area. Just fill with concrete level and finish

10-10-20

https://www.boards.ie/discussion/comment/121301419#Comment_121301419

Agreed. If the cable is rated for external use (can't tell from the photos) then paint the existing surfaces with a slurry of watery cement (as a primer), then backfill it with a concrete mix. Then after about 35 mins, brush it in a swirling motion with a sponge to lightly roughened up the surface and help it fit in with the existing finish.

boardtc

Thanks for advice. Not having the groove along the path would break symmetry as there's one at the standard regular intervals.

https://www.boards.ie/discussion/comment/121303230#Comment_121303230

New ideas to me, thanks.

The marshalltown concrete groover looks excellent though a stiff €26 for a one time use.

kirk.

https://www.boards.ie/discussion/comment/121303230#Comment_121303230

Doesn't look like swa anyhow

10-10-20

https://www.boards.ie/discussion/comment/121304840#Comment_121304840

I know - that's what I'm concerned about. Looks like T&E really.

10-10-20

https://www.boards.ie/discussion/comment/121304750#Comment_121304750

I've done the same effect with a simple trowel. It just takes some playing around with the concrete as it sets-up.

boardtc

https://www.boards.ie/discussion/comment/121304840#Comment_121304840

It's external cable alright. I might try your technique @kirk.

boardtc

https://www.boards.ie/discussion/comment/121305050#Comment_121305050

Not sure what T&E is, I bought the outdoor cable the electrician asked me to get, 1.5 SWA

10-10-20

https://www.boards.ie/discussion/comment/121389385#Comment_121389385

Well then it's fine. T&E is twin and Earth, hard to tell from the photo.

GreeBo

If you still have the concrete saw then just cut a line back in when your new concrete has set, in a year no one will notice :)

Asdfgh2020

Refilling shallow and narrow ‘trenches’ with concrete isn’t ideal…..most likely it will crack and break up over time….what depth is the ‘trench’…looks no deeper than 30mm from pic..? 75mm deep would be much better and have a better chance of lasting, not cracking etc