When designing and building your outdoor project, you must follow industry standards (Building Code) and make adjustments to account for the properties of ALTWOOD^®. Synthetic lumber is, on average, 50% heavier than wood (for example: Douglas Fir = 35 lbs/cubic foot, ALTWOOD^® = 55 lbs/cubic foot).

Foundations, Supports & Spans

Because of its weight, particular attention must be paid to foundation, supports and spans. In most applications, decreasing standard joist and / or beam span by 50% will be sufficient to support the extra weight and eliminate the possibility of sagging.

Decks

Standard 16" joist spacing is sufficient with 2"x4" or 2"x6" decking material.

Fences

We recommend 6 foot spacing between posts and a support of the bottom board at mid point (3 ft). Installing the bottom board against the ground is the simplest way to eliminate any potential sagging without the need for additional supports.