Best Practices Manual

3.4 Door Installation
Door Installation Detail 1 Router the RO | Hammer & Hand
  • Router the RO to make clean edges for applying liquid flashing.
  • Pass over outer edges with sand paper to get rid of any inconsistencies.
  • ROs should be 1” larger than door width dimensions and 1/2” larger than height.
  • Make sure sill is flat and level.
  • Make sure opening is square and plumb.
Door Installation Detail 2 Apply Joint and Seam Filler | Hammer & Hand
  • Apply Joint & Seam Filler to all joints to be covered in FastFlash.
  • Ensure that all nails are set, apply Joint & Seam Filler and tool into place.
Door Installation Detail 3 Tool Joint and Seam Filler | Hammer & Hand
  • Tool Joint & Seam Filler.
L-Metal Installation
Door Installation Detail 4 Set L-Metal
  • Set L-Metal into bed of Joint & Seam Filler.
Door Installation Detail 5 Apply Joint and Seam Filler Over L-Metal | Hammer & Hand
  • Apply another bed of Joint & Seam Filler over L-Metal to form a continuous barrier.
Applying FastFlash
Door Installation Detail 6 Apply FastFlash to Sill | Hammer & Hand
  • Apply FastFlash to sill, extending 9” out from the RO to either side.
Door Installation Detail Installing Wood Door Threshold | Hammer & Hand
  • When installing a wood door threshold, coat the bottom of the threshold  with FastFlash. Alternatively, the height of the rough opening can be sized slightly larger and composite shims can be used to elevate the wood threshold off of the sill.
Door Installation Detail 8 Install Door Threshold | Hammer & Hand
  • Install door threshold and sill.
  • Fasten accordingly to manufacturer’s specifications.
Door Installation Detail 9 Interior View
  • Insert backer rod and sealant between L-Metal and door sill and tool into place.
Door Installation Detail 9 | Hammer & Hand


Note: If the threshold is subject to moisture, the door needs to sit on a resilient shim material.


Interior View
  • Insert properly sized backer rod, taking care not to puncture or damage it.
  • Make continuous around door frame.
Door Installation Detail 11 AirDam Over the Backer Rod | Hammer & Hand
  • AirDam over the backer rod and tool the joint.
Door Installation Detail 12 Finish Door with Trim | Hammer & Hand
  • After interior flooring is installed, finish door with trim piece to hide sealant.

Door Installation Detail 12 | Hammer & Hand

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