adding lip to tarmac

A rubber strip, like a mini speed bump? Build a up with a repeated run of melted bitumen (as used in some road joints and cracks)?

You can get liquid bitumen:

Although if the OP wants it to be one piece with existing tarmac I would probably be thinking of more tarmac. You can get it in small bags:

Has anyone tried "rejuvenating" that stuff?

I have about 3/4 of a bag several years old, a GBFO gas burner and could organise a metal sheet to cook it on, if there's any hope it would become workable ...

I've never used that stuff, but I'd guess it hardens by losing volatile hydrocarbons, since it's designed for cold laying. Perhaps it needs a solvent of some kind?

Datasheet:

Heating it might drive off the remaining volatiles and make it harder?

Theo

I've seen utility companies sloshing a bit of diesel on it, but never sure if that was to prevent it sticking to tamping tools etc.

Would that not be a trip hazard though? Depends if its in a place where you might put a foot. Brian

Why not just seal around the base of your exiting drain cover?

I think that would look strange.

Why not make a feature, and use bricks on top of the Tarmac stuck together and to the tarmac to create the raised drain?

The photo in the original post shows what is described is a gutter cover is actually a 1 foot x 1 foot drain cover fitted to the bottom of the gutter down pipe and covering the drain.

Thats a great idea. I had toyed with the idea of a small concrete kerb but was unsure how to seal it. Many thanks

It depends what part of the country you live in. In some places a down pipe is known as spouting, gutters are known as shores etc.etc.

Why not just get another gully, the fired clay type are usually flat underneath with just a spigot poking through. Sit it on top of the existing gully, that will provide a lip.

Richard