I am installing a new 2000 sqft deck, in an urban home. It will get intense sun, need low maintenance. The builder wants to cover all 6 sides of each board. Is this realistic or even cost effective versus a good stain and regular upkeep and maintenance?
What is the best covering? I would like to keep something resembling redwood.
By all means, coat all six surfaces.
My favorite wood protectant is raw (NOT BOILED) linseed oil, but it's not for everybody. It takes a mule's age to harden, and it wants periodic recoating (exposed surfaces only) until it's fully built up. Nothing quite matches the beauty of a fifty-year-old well-maintained linseed-oil finish over natural wood, though.
One of the major factors in the wear and tear on outdoor wood is moisture absorption (and subsequent release). This causes swelling and shrinking of fibers and leads to cracks and eventual breakdown of the material.
The end grain is most susceptible to water penetration. Best practice says cover every side of a board with a protective coating, especially the ends. Many builders stick the each end of outdoor wood in a bucket of protective coating and let it sit overnight (obviously one end at a time).
Once installed, it is much harder to coat any surface but the top, so precoating before installation is the better way to go.
There are a wide variety of coatings and sealers. Some have more pigments to mask damage and discoloration on old wood. In new wood, you don't need pigment to mask imperfections. Consider a clear or natural penetrating sealer intended for the particular wood you are using.
Ultraviolet light and weather bleaching the wood pigments may also be an issue; even dark-colored woods tend to shift toward being a silvery grey over time. Some surface treatments contain UV blockers -- sunscreen for wood -- which can help limit this effect, and some stains (I'm not sure which or how many) resist it better than others.
(There's a nice Ipe deck around the corner from me, built several years ago, Mostly grey now, but when it's wet some of the original color comes back.)
