Decay Resistance
Moisture Control
__ Architectural detailing that sheds rainwater away from walls:
__ Overhangs all around (2-ft. wide)
__ Roof pitch between 3:12 and 6:12
__ Roof drip edge
__ If lacking overhangs, nonclogging gutters or diffusers
__ Covered entries
__ Cap flashing with drip edges above windows, doors
__ Extended, sloped window sills
__ Sloped porches, balconies, driveways, etc.
Roof leak reduction:
__ Simple roof design
__ No flat roofs
__ Minimal penetrations; leak-resistant vent systems
__ Properly installed flashing at penetrations, valleys
__ Step and kickout flashings if a roof intersects a wall
__ Higher performance underlayment for leak-prone roofing types
Continuous drainage plane in walls exposed to rain:
__ Drainage space behind cladding in high rainfall areas
__ Vented space behind cladding in extreme rainfall areas
__ Or, sealed masonry construction (reservoir system)
__ Flashing of windows, doors, etc. that continues drainage plane
__ Shingle fashion installation of all materials
__ Flexible flashing tape, waterproof coating or sill pans and corner
guards
__ Doors set in pan flashing or “seat” in slab
Hot, humid climate ideal wall assembly (zones 1A, 2A, 3A):
__ Air flow retarder to the exterior
__ Vapor diffusion retarder to the exterior, if used
__ Permeable interior finish (no vinyl wallpaper)
__ Unfaced cavity insulation
Mixed, humid climate ideal wall assembly (zone 4A):
__ Air flow retarder to the interior
__ Permeable interior finish (no vinyl wallpaper)
__ Vapor diffusion retarder that adapts to seasons:
__ > R 5 insulating foam sheathing or foam core
__ Kraft paper faced insulation to interior
__ Special membrane that is low-perm in winter and high-perm in
summer.
Water managed foundation:
__ Ground slopes away from foundation
__ Gasket (capillary break) between foundation and framing
For slab on grade house:
__ Durable plastic sheeting under slab and lining the grade beam
__ Coarse gravel drainage bed under slab
For raised house:
__ Ground level under house higher than outside grade
__ Plastic ground cover in enclosed crawl space
__ Entire wood subfloor treated to resist decay
__ Drainage board for any below grade walls
__ Insulation system that minimizes condensation on wood framing
Other:
__ Exhaust fans, clothes dryer do not vent under house or into attic
__ Wood, fiber cement siding backprimed
__ No plumbing within exterior walls
__ Stainless steel hoses for clothes washer
__ Sloped floor and drain or drain pan for clothes washer, water heater
__ Air infiltration control (see Energy Efficiency section)
__ Humidity control system (see Healthy/Indoor Air section)
Long-lasting Materials and Equipment
__ > 40-year roofing warranty, 12 year total-system space 100% warranty
__ > 50-year cladding warranty or masonry
__ > 10-year window frame, 20-year glass warranty
__ Pressure-treated wood, masonry, steel structural components
__ Fiber cement, plastic fiber composite or other long-life trim
__ Plastic lumber or pressure-treated wood decking
__ Appliances, equipment with longer-than-average warranties
__ Long-lasting floorings
__ Foundation designed for soil conditions