Installation Prep
How To Measure Jamb Depth
Measure jamb depth correctly so the prehung frame matches the wall condition instead of creating trim and fit issues.
Why jamb depth belongs in the buying flow
On a prehung order, jamb depth is not a minor accessory detail. It affects how the frame sits in the wall, how casing transitions, and how clean the installation feels once the unit is in place.
How to measure it
Measure from the inside face of the finished wall on one side to the inside face of the finished wall on the other side. Do not use the casing width, and do not guess based on a nominal stud size if drywall, plaster, or wall build-up has changed the finished dimension.
Where buyers go wrong
- measuring trim instead of the finished wall depth
- assuming every interior wall uses the same jamb size
- skipping the measurement because the previous door looked close enough
- forgetting that exterior conditions may call for a different jamb range than interior openings
When to double-check
Double-check jamb depth when the wall has tile, layered finishes, older plaster, or any remodel condition that makes the opening less predictable than new construction. If the dimension is unusual, confirm it before the order reaches checkout.
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