doug fir, western red cedar, or redwood
jcaldwell
| Posted in General Discussion on
The decking material for a deck I’m building for clients is going to be IPE. A dark-colored hardwood. There’s also going to be a tea house and pergola. The customers don’t want to foot the bill for IPE everywhere, so what do I recommend for the pergola and tea house? My initial thought was Doug fir, as a nice contrast. In the teahouse that’s fine b/c it’s protected from weather. I’m concerned with the pergola though. Won’t it age too quickly? The deck is south facing. I live in Ontario, Canada.
Replies
All wood, even Ipe, will weather and turn gray with time. The more exposure to sunlight, the more quickly it will gray. Repeated wetting also speeds up the aging.
To maintain a consistent color on outdoor, unpainted wood, there will have to be regular re-coating with a semi-transparent stain. Every two years, minimum.
Doug fir that's not in contact with the ground will last very well, and be much cheaper than cedar or redwood.
If your customer is willing to accept the maintenance associated with regular staining, it doesn't matter much what wood you choose--the appearance will be according the color of the stain they use.
If they're willing to accept the graying and weathering, it also doesn't matter much--it'll all look the same in a few years anyway.
The pergola will probably have exposed end grain on the tops of its posts, and in your climate, will be subject to accelerated rot. This is where cedar would outperform Doug fir. But you could also fit the tops with copper or galvanized "lids" that would protect them, which is what I just did on a pergola for a customer that wanted 7" posts with exposed end grain.
What about the overall lifespan of each wood? When exposed to weather, will Ipe not outlast everything else by many many years? If that's the case, the soft wood pergola would have to be replaced far before the IPE decking was even close to needing replacement?What about just doing the pergola in IPE, and leaving the teahouse (protected) in Doug Fir?
Any wood that's protected from ground contact or constant wetting is going to last a very long time.
There are log houses in many parts of the country, made from timbers of pine, fir, aspen and other woods that are not considered to be particularly rot-resistant, which have lasted well over a hundred years.
Ipe will be considerably harder than fir, and because of its hardness, will resist erosion better. Wood wears away in the wind and rain as even stone will. The Ipe will also make a tougher walking surface, which is what a deck is all about. But the pergola will serve a different purpose.
For the purposes of your clients, it probably won't make much difference--some future owner will tear it all down before the Ipe gets to prove its toughness over the fir.
The way the wood is sawn will have an effect on its appearance and longevity.
About 10 years ago, I made an Adirondack love seat of gorgeous, quarter-sawn, old-growth, tight-grained Douglas Fir. It stays outdoors through our long, cold winters and the heat and dryness of summer. It has weathered to a beautiful silvery-gray, and has never been treated or finished in any way.
Western Red Cedar is very soft. You can dent it with your finger. So it may not hold up as the customer likes. It is very difficult to work with for that reason. Even setting a board down on a plane shaving will dent it.
Some people have an adverse reaction to it. For me, its almost like a mild flu -- muscle aches, tiredness, and headache. So I can't work with it any more. Reactions to it are not as common as for, say, poison ivy, but it's not as "inert" as maple, pine, ash, oak, etc.