(1)
Sentences (2) to (4) pertain to lateral support for walls described in Sentence 9.15.4.2.(1).
(2)
Foundation walls shall be considered to be laterally supported at the top if
(a)
such walls support a solid masonry superstructure or flat insulating concrete form wall,
(b)
the floor joists are embedded in the top of the foundation walls,
(c)
the floor system is anchored to the top of the foundation walls with anchor bolts, in which case the joists may run either parallel or perpendicular to the foundation walls, or
(d)
they extend from the footing to no more than 300 mm above the finished ground level and are backfilled on both sides such that the difference in elevation between the finished ground levels on either side of the wall is no more than 150 mm.
(3)
Unless the wall around an opening is reinforced to withstand earth pressure, the portion of the foundation wall beneath an opening shall be considered laterally unsupported if
(a)
the opening is more than 1.2 m wide, or
(b)
the total width of the openings in the foundation wall constitutes more than 25% of the length of the wall.
(4)
For the purposes of Sentence (3), the combined width of the openings shall be considered as a single opening if the average width is greater than the width of solid wall between them.
(5)
Flat insulating concrete form foundation walls shall be considered to be laterally supported at the top if the floor joists are installed according to Article 9.20.17.5.