I'm replacing an outdoor sliding patio door set with a new one that has almost the exact same dimensions - luckily the previous homeowner (family) did not go with custom-sized doors.
The issue is that the door will reside over three concrete slabs - the patio itself was installed piecemeal through the years, so toward the inside there are two slabs that meet 2/3 of the way through the jambway, and on the other side is a brand new slab that I poured last year myself (Quikrete, replaced a set of about 15 thin patio stones on top of dirt).
While the concrete that I poured is passable (isn't completely level), there is a big gap at the meeting of both slabs (the corner of the one seemed to break off - so about 5 inches from the gap there's a tad of a hump).
The new patio door set I ordered has about a 4" jamb, so that's about how wide I'd need to level. How do I level this so my new doors aren't all cattywampus?