Would you recommend leveling the floor or using a super seal under the door. Do they make a chanel that goes under the door to level it? I am thinking like a chanel for a storm door.

By your question, I take it the doorseal isn't sealing properly.

Mine was the same.

I used mortar,many layers in the thicker areas,allowing dry time between layers.

I also used a mid sized replacement seal.When I got the new seal the Mfgr. Stated that if the new one didn't seal tight enough to put an old garden hose inside it,It closed the opening off, no water penetrates in the shop anymore.

Hope this what you were looking for,

Ken