Fixing gaps in a Concrete Door Step.

[JD2012]

I was wondering what forum readers would suggest to fill in horizontal gaps between a front door step and the door. They are not huge gaps. I think its just caused by shrinkage as the house is about 60 years old.

I was thinking something along the lines of a mastic sealant as I want to be easy to use and not hugely expensive. It also goes without saying that it must be waterproof.

Thanks

 

[RandomGrinch]

I've found this stuff:
https://www.toolstation.com/fischer-dec-premium-express-ready-mixed-cement-cartridge/p95602
really useful for fixing small cracks in exterior render and have repointed a small part of a wall with it.
It's basically a ready to go mortar in a tube. Though be warned, a good, heavy duty caulk gun will be needed; the mortar can be quite hard to push out!

 

[JD2012]

The biggest gap is about 5 mm wide the rest are smaller.