Plastering with cement plaster shall be in accordance with ASTM C926. Cement materials shall be in accordance with one of the following:
- Masonry cement conforming to ASTM C91 Type M, S or N.
- Portland cement conforming to ASTM C150 Type I, II, or III.
- Blended hydraulic cement conforming to ASTM C595 Type IP, IS (< 70), IL, or IT (S < 70).
- Hydraulic cement conforming to ASTM C1157 Type GU, HE, MS, HS, or MH.
- Plastic (stucco) cement conforming to ASTM C1328.
Plaster shall be not less than three coats where applied over metal lath or wire lath and shall be not less than two coats where applied over masonry, concrete, pressure-preservative-treated wood or decay-resistant wood as specified in Section R317.1 or gypsum backing. If the plaster surface is completely covered by veneer or other facing material or is completely concealed, plaster application need be only two coats, provided the total thickness is as set forth in Table R702.1(1).
On wood-frame construction with an on-grade floor slab system, exterior plaster shall be applied to cover, but not extend below, lath, paper and screed.
The proportion of aggregate to cementitious materials shall be as set forth in Table R702.1(3).