I stepped onto the old, musty redwood deck and instantly retreated! I had almost fallen through! Something had to be done… fast!
The owner, and elderly gentleman, asked if I could use “natural materials”. Since the deck is always shaded, I expect the new, treated pine decking (the boards on which one walks) to not twist and crack, as is often the case when a deck is subject to direct sunlight (dry on one side and moist on the other). Each board is fastened to the framing with stainless steel screws. Notice how the deck is built around a tree!
When a deck is exposed to direct sunlight I recommend using composite decking materials. There have been significant advances in the manufacture of composite boards; a 25 yr. warranty is common. The price of composite decking is higher than it is for treated lumber, but long term maintenance is reduced. Composite decking is usually blind fastened, while wood decking is face-screwed.
Framing members, spaced 16″ apart, are made of pressure treated Southern Yellow Pine. Structural beams lie on top of 4×4 posts. My post spans do not exceed 6 feet. Each post is set 36″ below grade, housed in a cylinder and resting on a bed of gravel. Gravel (not dirt) fills the cylinder surrounding each post. This feature promotes water drainage and guards against ice heaves.
The handrails system is composed of cedar posts, cedar railings and 1” diameter aluminum balusters. Each post rests within, and is firmly fastened to, an aluminum sleeve, which in turn is bolted to deck framing. Sleeves are hidden from view behind cedar plinth boards. I applied several coats of a clear sealant to the cedar.
The original redwood deck had lasted 35 years. I expect the new deck to outlive the old. Deck boards and cedar rails will eventually turn weathered gray. Because the deck lies in the shade mildew must occasionally be power-washed off.