On Apr 19, 2014, at 1:18 AM, Judy Opfell  wrote:

> [snip] The spacing of floor joists,
> 12", 16" or 24" is determined by the span, the width of the joist, the
> species of wood and the type of flooring to be applied. The key factor is
> the allowable amount of deflection, you want a fairly stiff floor. If you
> were going to lay down a 2" thick subfloor, you could use a 24" joist
> spacing, providing the overall span was minimal and the joists were wide
> enough. To a lesser extent, the same is true of wall studs, ceiling joists
> and rafters, the center-to-center spacing depends on the material to be
> applied, the span and the width of the framing member.
> [snip]

        A thought just occurred to me.  When Aunt Tilly was waltzed across the
living room floor in 1910 she likely weighed 180-200 lbs.  Now she likely weighs
250-300, and Uncle Buck weighs 300-350.  That is quite the china-cabinet-
rattling dynamic load.  One sees items in the news about the need to increase
chair sizes in public spaces.  Has their been a need to increase joist sizes?

Regards,
Steve