if caulking is not designed to be exposed in a wide strip ......say , wider than an inch ,
then why not use something that is designed to be in full sun ,
such as ,
the white 'flat roof' roofing goop .
the trouble with a wedge shaped concrete strip , is , it's brittle and won't adhere to the existing concrete slab , and the narrow edge will crack off if anyone steps on it after a few weeks.
i've been trying to formulate a fix for those doors for years . one guy suggested, make a 1 inch deep saw cut about 8 inches away from the door , then use aluminum flashing , put caulk in the sawcut , push the flashing edge in , then bend it up to the door, creating the wedge shape.
how to attach to the door? not sure. this is what stopped me , we'd need a waterproof and 12 foot long seal between the door and the metal strip.
i think a slot drain would be best.
mr wizard ( Rob) ,please help , tooter turtle
email me at 'chahlieandkathy at yahoo dotto com'