A board exactly ${12}^{\text{'}\text{'}}(305mm)$ wide was quartersawn from a

green softwood log$,$ then seasoned to a moisture content of $12\%.$

How wide is it now? Show calculations.

${12}^{\text{'}\text{'}}\frac{2\mathrm{.}7}{100}=0\mathrm{.}324$

${12}^{\text{'}\text{'}}-0\mathrm{.}324={11\mathrm{.}676}_{\text{a}\text{w}\text{s}}or296\mathrm{.}57mm$ avs

The platform frame shown in Figure $5\mathrm{.}2$ of the text contains a

total of $33"(838$ mm $)$ of cross$-$grain wood between foundation

and roof.

a$.$ Assuming that plainsawn framing lumber shrinks across

its grain at a rate that is an average of the shrinkage

rates of tangential and radial shrinkage, how much will the

roof drop if the lumber is installed at $19\%$ moisture

content and eventually dries to $15\%?$

b$.$ Assuming that the $212$ wood floor joists at both floor

levels are replaced with laminated veneer lumber joists

with negligible shrinkage, how much will the roof drop under

the same change in moisture conditions?

Show calculations.

Considering the tendency of plainsawn lumber to cup during

seasoning, which way should the boards on an outdoor deck be

laid so that they will not trap rainwater?

a$.$ Circle the properly laid board.

Top of supporting beam

b$.$ Can you think of any other factors that might influence

the choice of orientation?