A.Steve Thomas, who has worked for over 20 years in the stucco and masonry industry in Columbus, Ohio, responds: One possibility might be to try patching with nonshrink grout — but as you note, matching the rough texture would be hard, and getting a color match would be even harder. I would use a simpler approach: Replace the new trim with a wider, thicker trim, or add a band molding around the outside edge to cover the gap (see illustration, below). If the original PVC trim has been glued in place, the band molding might be easier to install, and if chosen well, it could enhance the appearance of the entryway. Use a foam backer rod and a high-quality sealant to finish the job.
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