I am installing a new entry door for my shop and the floor is a concrete
slab. What sort of caulk or sealing method would be best to seal between the
door sill and the concrete floor?

One fellow I met mentioned some sort of asphalt based sealant. Another
person mentioned putting a 1/2 inch of pressure treated lumber between the
door sill and the concrete floor.

I am not concerned about clearances for carpeting as this is for a workshop.

I just don't want air or water seeping in under the sill.

What is the best way to deal with something like this?

Thanks

Pierce