Router or sand the rough opening (RO) to make clean edges for applying fluid flashing.

• Pass over outer edges with sand paper to get rid of any inconsistencies.

• ROs should be 1” larger than window dimensions, both width and height. If space requirements are not met, square or fix before continuing.

Slope the sill using beveled siding or a wedge.

• Apply Joint & Seam Filler to all joints and voids larger than 1/4” that are to be covered in FastFlash.

• Ensure that all nails are set, apply pink Joint & Seam Filler and tool into place.

• Apply FastFlash to sill, extending 9” out from the RO to either side.

• Take care not to FastFlash too far below the RO because the transition strip will become embedded on contact and the water-resistive barrier (WRB) will not be able to slip underneath.

• Recommended: spread FastFlash 2” down from the bottom of the RO.

SureFlash Installation:

• Install transition sheet.

• Must extend down from sill at least 4” farther than FastFlash to adequately lap over WRB to be installed later.

• FastFlash around the rest of the RO and tool over top edges of transition strip to avoid reverse lapping.

• Provide complete, level support for windows, where framing allows, by installing plastic or decay-resistant wood shims.

• Use horseshoe shims to hold window flange off of the sheathing so water can drain if the window fails.

• RECOMMENDED: 1/16 or 1/8” horseshoe shims.

• Insert window in RO and fasten according to manufacturer’s specifications.

• Apply Joint & Seam Filler to head and side flanges and tool. For special cases where flanges must be taped for warranty purposes seek additional guidance for suitable alternative.

• NEVER seal the sill.

Interior View:

• Insert backer rod.

• Apply sealant on top of the backer rod and tool into place (see Sealant Joints section).

Slide WRB under transition strip.

• Apply WRB around window.

• Complete WRB face, lapped.

• Make sure WRB is lapped over the built-in flashing at the top of the window and taped.

• Install trim.

  Note: See alternate rain screen head flashing detail in section 4.2 Top of Window.

• Cut a slit in the WRB, fold up, and use tape to hold the flap out of the way while the head flashing is installed.

• Attach head flashing.

• Apply Joint & Seam Filler to the top of the back leg of the head flashing.

• Tool Join & Seam Filler into place.

• Fold WRB flap back down and tape the slit to prevent water intrusion.

• Attach siding.

• There should be a 1/4” gap between the bottom of the sill trim and the siding underneath for expansion and contraction.