Exterior Lath

The residential inspection checklist for exterior lath includes:

  • Weep screed (min. 26 galv. sheet gage corrosion-resistant), with a min. 3 ½ inch vertical attachment flange, located a min. 4 inches above the earth and a min. 2 inches above any paved surface, section R703.6.2.1, I.R.C.
  • Water-resistive barrier of two (2) layers of Grade D paper or equivalent, section R703.6.3, I.R.C.
  • One and one-half (1 ½) lb. density foam material / installation per current ICC ES report, including: horizontal T & G joints (taped and tight) and vertical backing at vertical butt joints (taped and tight) ***Please note: Foam plastic is not to be exposed to building’s interior, including attic spaces. A thermal barrier (min. 1/2 inch gypsum wallboard or equivalent) separation is required, section R316.4, I.R.C.
  • Woven wire lath lapped at joints per current ICC ES report.
  • Woven wire lath connection to foam panel, stapled max. 6 inches o.c., section R703.6.1, I.R.C.
  • Woven wire lath shall extend to and cover the attachment flange of the weep screed, section R703.6.2.1, I.R.C.
  • All wire lath corner aids and all pop-outs to be nailed or stapled max. 6 inches o.c., section R703.6.1, I.R.C.
  • Horizontal lath greater than 16 inches in depth must be diamond mesh or equivalent (incl. horizontal surfaces at archways, patio beams, entry openings, etc.).
  • Foam panel vertical butt joints and gaps at window perimeter: maximum ¼ inch or caulked per ICC ES report.
  • All penetrations to be caulked, section R703.2, I.R.C.
  • Electrical boxes and extension rings to extend out to exterior face of foam panel or minimum one hour fire-resistive rated caulking at exposed cut edge of foam panel opening, City policy.
  • Only perimeter of electrical service backing panel against foam panel to be caulked. ***Please note: Required minimum ¼-inch ventilation air gap between electrical service panel and electrical service backing panel, section E3907.2, I.R.C.
  • Damaged woven wire lath, weep screed, and/or damaged foam panel (including UV damaged) requires replacement.
  • Metal roof flashing and counter-flashing shall be installed to divert the water away from the roof intersections, wall/roof intersections, etc. Flashing to be minimum No. 26 galvanized sheet metal, section R903.2.1, I.R.C.