install windows

[msimerson]

General Rules / Tips

• don't X-cut opening in house wrap
  • make a level head cut
  • make an inverted Y cut
• Use flexwrap to make one-piece self-healing sill pan
  • extend up the jamb 1 tape width
• Do not caulk sill flange!
• Head flashing adheres directly to sheathing
• make a beveled sill pan using clapboard / lap siding

• 100% silicone is not compatible with Tyvek

  Window Install Steps

  1. cut house wrap / WRB to expose rough opening
     • cut level along window header
     • cut 45° from corners up 5". Fold the flap up and tape it out of the way.
     • from sill corners, cut 45° up to the center
     • cut from center of header down to the angle cuts
     • fold sides in, cut the wrap 1" inside the jamb and tape
     • so foam sealant seals window to framing (vs wrap)
     • cut wrap at the bottom flush with the sill
  2. Sill Pan flashing a. cut a length of clapboard to the window width b. install clapboard sloping down and out c. cut a length of formable flashing: window width + (tape width x 2) d. apply flashing to form the sill pan
  3. Install Window a. install sealant bead on the nail flange along the nail holes or on the house wrap so it falls under nail holes in flange NOTE: head and jambs only. The sill must drain! b. plumb, level, and square (cross measurements) the window c. nail windows in
  4. Jamb flashing a. cut 2 strips window height + (2 x tape width) b. tape the jamb nailing strips
  5. Header flashing a. cut 1 strip window width + (2 x tape width) + 2" b. fold down and trim house wrap flap up 1" so it doesn't contact window frame c. apply header flashing strip d. fold down house wrap e. skip tape housewrap f. tape the house wrap corner slits

  Optionally: install Drip Cap / cap flashing a. put a bead of caulk on window head b. install cap flashing c. 45° tape the housewrap ends

Use elastomeric latex caulk * use "sealants" * 3M polyurethane 540 * siliconized acrylic caulk

references

• http://buildingscience.com/documents/insights/bsi-067-stuck-on-you
• return to the backyard tape test
  • Dow Weathermate: avoid on plywood, middling on housewrap
• http://buildingadvisor.com/wall-flashing-details/
• https://pro.homeadvisor.com/article.show.Flexible-Flashings.13630.html
• http://www.finehomebuilding.com/2008/07/03/installing-and-flashing-windows-correctly
• http://www.plygem.com/wps/portal/home/brands/plygem-windows