Right wood for the right job

Hello carpenters, foresters, sawyers, and farmsteaders.

Woohoo!  I've received permission to build from my county, and have laid the foundation and beams for my first DIY farm structure -- an off-grid multi-purpose farm office/storage/growing space.  

I'm using MM Ground Screws (https://www.mmgroundscrew.com/) supporting double 2x8 beams, upon which will go 2x6 joists, flooring etc. in conventional stick framing style.  It'll be two stories, mostly following a plan, but making changes here and there to suit my needs.

Now for some time I've had my heart set on milling a sizeable portion of the lumber for this project from my own forest.  As I walk the woods, I can't help but look at each tree around me, and wonder:

"Where will you do the most good, tree?"

So my question is, which species are ideal for:
1)Joists and beams
2)Flooring
3)Studs
4)Interior walls
5)Exterior shiplap

I think I have a general idea of what constitutes the right wood for the right job, but is there a good table or diagram out there?  

P.s. I'm thinking of trees primarily found in Eastern USA.

The American Wood Council has your back! You'll have to sift through the website yourself, but they have all kinds of info for building including info about species and their strengths in different uses.

I just used it to frame up my two story stick house. Everything is feeling good.

If you build any walls above ten feet high, make sure you use appropriately sized lumber and spacing. I have 16 ft walls in a small area of the living space and had to use 2x6s, 8 to 10 inch on center. Just thought I'd through that reminder in there because I had to re-draw the plans and find wind exposure category info and all kinds of stuff.

Congratulations on receiving the permission! That sounds like a big milestone.

I had a similar moment earlier this year and will be starting on a build of our woodland workshop/barn next year. I'm currently wondering what timber to use too - our choices are between resinous softwood (Larch, Douglas Fir) or native hardwoods (Oak, Chestnut, Ash).

In general, I would aim to use the best pieces of wood for the main structural framing, the roof and the floor. By best, I mean good, knot-free heartwood of trees that will be both strong and durable. This will be the heart of the building and, if all else fails, the rest of it (particularly the shiplap cladding) can be replaced around it.

In the UK, the ideal would be English Oak as it is both incredibly durable (high tannin content, dries rock hard) and strong, if not exactly flexible. Chestnut is harder to come by (where I live, at least) but it is seen as a poor person's Oak - it has reasonable levels of tannin but it won't last quite so long. I imagine that the White and Red Oaks of the USA are similar but, as Bridget mentions, there are online databases that will tell you.

Timber that will be exposed to the elements should be durable too else it will rot or get eaten away very quickly. Here there are two choices: softwood with lots of resin or hardwoods with chemicals that prevent decay (tannin being the most common). Softwoods such as Larch, Douglas Fir and Western Red Cedar are commonly used over here. Pine is generally a poor choice and would require oiling. Ideally, only the heartwood should be used as the sapwood is far less durable.

You can be less fussy about interior timbers as these do not need to be so durable. If the external cladding is watertight, and the roof is good, these will receive very little moisture and are at a low risk of rotting. We have used housewrap (which, along with screws, I think are excellent modern additions to building techniques!) for a recent shed build, with Douglas Fir 'waney edge' cladding on top of that, and it is completely weatherproof so far.

Floorboards are a bit of an exception here as they can get wet, particularly near doorways, windows or around sinks and bathrooms; they also get a lot of wear so pick a hard-wearing (but not necessarily rot-resistant) species).

A summary of the woods available to us and our ideal choices would be:

Ash (F. excelscior) - very strong and flexible, prone to insect attack; readily available for us. We might use ash for internal workbenches and possibly floorboards and internal windowsills.

Oak (Q. robur) - strong and extremely durable; cracks as it dries; expensive for us, despite being native and fairly common. Usually worked green as it becomes difficult to work when seasoned and progressively harder as it ages and dries. We would love to use oak for the main frame (posts, wallplates; braces; rafters) but it might be too costly.

Chestnut (C. sativa) - strong and moderately durable; not readily available in Wales (but it is in SE England). This would make a good substitute for Oak.

Elm (U. minor) - strong, resistant to cracking and splitting but very prone to insect attacks. Interestingly, it doesn't rot when kept wet so it has been used, traditionally, for water wheel hubs and coffins. I have some large pieces of woodworm-eaten elm that I would like to find uses for but I haven't much clue what.

Larch - reasonably strong if knot-free, moderately durable and cheap when available. Larch is becoming harder to find due to a disease which often restricts the movement of the timber. We have used Larch as a framing timber for small structures (4x4s, 2x4s in log stores etc.) and it is nice to work with.

Douglas Fir - as with Larch, although I've heard it is slightly stronger but slightly less durable. Our shed is mostly build of DF. We may well end up using it again for the barn next year as it is the path of least resistance to us (and a good compromise between price, strength and durability).

Western Red Cedar - I've heard the most durable of the three softwoods here but I have almost no experience with it - only via beehives which are commonly made of WRC. Not often available here. Very attractive grain pattern.

Willow (Salix sp,) - stringy grain, prone to cracking and splitting. Not very strong. We have loads of willow so it is tempting to find a use, internally, perhaps as rods in laths/hurdles that can be plastered for internal walls.

Hazel (C. avellana) - lightweight, moderately strong but not very durable. Again, we have a lot of hazel, some under coppice rotation (so in the form of straight rods) and it would be nice to find a use for some of it. Mostly we use hazel for hurdles, beanpoles or as temporary stakes for trees. The curtain poles in house are simply lightly-sanded hazel rods of 1" diameter.

I hope this was of some use. I enjoy learning about the traditional uses of the various plants and timber trees here in the UK (and I can highly recommend a book to others reading: Woodland Crafts in Britain - Traditional Uses of Trees and Timbers by H. L. Edlin).

If my post feels a bit haphazard, it's because I'm currently training a tiny puppy that is very attention demanding. I'll try and re-read and correct any mistakes later if I find any.

All the best with your planning + build.