The IBC and AWPA (American Wood Protection Association) standards require pressure treatment of
wood in decay-prone climates when in contact with moisture-retaining materials
(masonry/concrete), near grade, or within splash zones.
A: Moisture can wick from masonry/concrete into wood → decay risk.
B: Close proximity to soil promotes decay/insect activity.
D: Siding <6" above grade risks splashback and prolonged wetting.
E: Window casings <24" above grade are exposed to rain splash.
C: Roofing/flashing interface doesn’t require PT unless actual contact with wet substrate is expected.
F: Doors with thresholds don’t require PT unless the door bottom is wood in constant wetting.
PDD Reference: IBC §2304.11; ARE 5.0 PDD “Materials—Wood decay & termite resistance.”
