How to Install a New Door Jamb
Step-by-step instructions for installing a new door jamb and adding decorative trim.
Materials and Tools:
12 to 20 cedar/impervious shims/spacers
1/4 pound of 2-inch galvanized roofing nails
1 16d nail
12 to 30 feet of closed cell foam backer rod/sealant backer
door flashing tape
exterior polyurethane or silicone sealant
low-pressure polyurethane door foam (DO NOT use high-pressure or latex foam)
1 aluminum sill support or 2x4 wood blocking
15 to 40 feet of interior trim and/or jam extensions
small flat blade screwdriver
hinged patio door
primer and paint
You can easily increase your home’s energy efficiency by replacing an old glass slider with new, insulated hinged doors.
Start by removing the old slider.
Make sure the opening is plumb and level. To check for plumb, run a beam from a laser level.
The new door should be 3/4 inch narrower than the opening and 1/2 inch shorter.
Install a water resistive barrier at top and bottom of opening.
Attach sill-flashing tape to sill.
Attach a sill support to the exterior of the box plate, flush with the subfloor.
Remove screens, hardware and/or grilles from new door. Do not remove plastic shipping spacers yet; they will keep the door square during installation
Place three beads of sealant inside the entire opening: one 3/4 inch from the exterior, one where the threshold will go, one 1/4 inch from the exterior edge of the wood blocking.
You will need 2 or 3 people for this step. From the outside, insert the new doors into the opening.
Set the bottom of doorframe in place first, then tilt top into opening; DO NOT slide; sliding will disturb sealant lines.
Plumb and square doorframe, locking it into place with shims.
Fasten nailing fin to opening with 2-inch galvanized roofing nails and remove shipping spacers.
Insert a 3-inch screw into each hinge, making sure it penetrates structural framing.
Apply side and top flashing tape and fold down water resistive barrier. Flashing tape should cover entire nailing fin but not extend onto doorframe. To prevent water from getting behind tape, top flashing tape must overlap side tape.
Insert insulating foam sealant between doorframe and rough opening. DO NOT USE high-pressure or latex foams.
Install hardware and backer rod.
Seal outside perimeter with exterior sealant. To stay flexible, sealant should be applied in the shape of an hourglass.
Finish interior and exterior surfaces with primer and paint.