Advice for filling hole in floor

[DIY67]

The builder who did some work on our kitchen was supposed to knock out all the hard concrete and replace with old floor tiles up to the door. After chipping away and leaving a hole he never returned to finish. Can anyone advise what is best to re-fill this hole as I don't think normal mortar will stand the test of time as the hole is too shallow.. A doormat will be going over it. The concrete already in place is rock hard. Perhaps resin ? For now I have a thin tin plate over it so the matt doesn't get a hole.

Thanks.

 

[Deluks]

I'd just plop some stiff mortar in there. I would've said use self levelling compound but not worth buying a bag just to use a spoonful.
Put your tin plate back over it to protect it from foot pressure going through the doormat, or a bit or hardboard or ply.

 

[Ivor Windybottom]

Thoroughly hoover, brush then wet it all first, to prevent the old concrete sucking the water out of the new, detaching it.

Ideally paint it with SBR or PVA. But not worth buying some if you don't have any.

If it cracks then do what really needs doing - break it all out, reduce the level then tile over.

 

[DIY67]

Ok, thanks. There is a live gas pipe there but it's been there many years. I did ask my gas engineer and he said pretty much the same as you guys. I don't want to chip away at it anymore for obvious reasons.

 

[ree]

OP,
Did the "gas engineer" you refer to do a pressure test on the gas installation?

 

[DIY67]

He was servicing the boiler.