Hi John.

I was really wondering about your figure of 6.45 x 10^-6 until I realized you folks in the US don't use international (metric/ISO) units for this. My figure is 11.1 x 10^-6 K^-1. But I found this page in our archive where someone else uses your value as well.

Yes, you are correct that the deck will expand in all directions. So both the width and the length (and actually the thickness) of the deck will expand by this amount per degree of temperature variation. You just multiply by the linear dimension in each case.

For example, if the initial width is 100 feet, and the temperature increases from 72 to 150 degrees Fahrenheit, then the width should increase by (150-72) x 100 feet x 6.45x10^-6 which works out to 0.05 feet or about 19/32 of an inch.

Hope this helps,
Stephen La Rocque