Effect of Composite Action on the Strength of Wood Roofs

Table 1

Analytically predicted average strength increase due to NPCA as a function of ultimate strength of the joist.

Analytically predicted average strength increase (%)
(psi)
1000	3.872	2.673	2.107	1.697	1.420
2000	3.103	2.148	1.695	1.366	1.143
3000	2.549	1.766	1.394	1.123	0.940
4000	2.139	1.482	1.169	0.942	0.789
5000	1.829	1.267	0.999	0.804	0.673