Decking basics.  Is that 'bounce' near the front door supposed to be like that?  Is the discolored paint around the nail holes a sign of problems?  Some boards look a bit funky on the ends, is that a concern?  The paint keeps peeling off the decking, why? Hmm, 80 year old house, maybe eighty year old decking...

Okay, the old stuff is shot, but what now — Tongue and Groove fir, pressure treated, mahogany, composite? There are several options in varying price ranges, and with each, of course, some pros & cons. The key points along with budget considerations should be appearance and longevity.  A brief run-down below.

Fir is the most common original decking on Boston porches, almost always tongue and groove fir.  As implied by the name, one piece literally interlocks with the next and, once painted, creates a fairly tight, water-resistant seam. This was an important feature in an era when most porches had a finished wooden ceiling on the level below.

Pressure Treated lumber has been in use for many years, and over time both the appearance and quality have improved.  It's both rot and insect-resistant as a result of being 'treated' with various compounds.  The original CCA (copper-chromium arsenate) was phased-out by the EPA on 2004 and today the wood is treated with more human-friendly compounds.  All PT woods should be finished unless one honestly prefers a sort of driftwood gray, abandoned shack look.

Composite decking is available under a dozen brand-names -- Aztek, Fiberon, Trex, etc -- and it's essentially the same product.   As the name implies, composite consists of wood fiber, plastics and varying fillers, tinted and then reformed into a board-shape using exterior epoxy.   

Pros & Cons. 

1X4 T&G fir.  Pros: looks great with a clear or oil finish.  Cons: forested new fir is not nearly as durable or rot-proof as the original old-growth fir. Finish should be consistently maintained.  About $1.25 a linear foot, as in 1" x 4" x 12." FYI, the same specs are typically available in mahogany.

5/4 X 6 pressure treated. Pros: quite durable, moderate cost and readily available. Cons: finished appearance tends to be 4 or 5 on a scale of ten.  Paint it, stain it or put rugs on it -- it still looks like PT wood.

5/4 X 6 composite.  Pros: an amazing variety of colors and surface patterns. Cons: somewhat expensive and often needs to be pre-ordered.