R802.2

Section R802.2 is titled 'Design and construction' and covers the requirements for roof-ceiling design and construction using wood and wood-based products. A configuration which prevents roof thrust being applied to the support structure, and a cross-reference to 3 figures in this code or another standard which roof-ceiling assemblies shall be designed and constructed in accordance with is established.

The model shows a partial gable roof-ceiling assembly bearing on walls (with arrows representing load being applied to the roof). The ceiling joists are then removed, and the load on the rafters pushes them downward at the ridge forcing the top of the walls outward, which will likely lead to catastrophic failure of the building.