Do you buy dried wood? Or cut it green and wait to season?

I'm looking into boatbuilding and am interested in making a traditional wooden sailboat.

However, I need the wood to be dry.. Do people here manage to source dry wood? Do you know what kind of places in the UK I can find dry oak for framing and dry larch slabs for planking?

Or is that generally not done, and people cut the wood and wait over a year or two (!) for the wood to dry before building?

 

Most people buy dry wood, kiln dried that is. To buy green lumber you need to catch it before it gets into the oven, wich means talkin to the sawyer or buying logs directly from the wood. If you buy sawn wood, unless you specify otherwise, it will be kiln dried. Air dried wood in sizes big enough for anything other than dinghy framing is more or less unobtanium, because the rule is one year/ inch of thickness.
You don't say what you want to build, but a lot of timber used in traditional building is not dried beforehand. Some timber is steamed (frames, stringers, planking), some is boiled (crooks for breasthooks, etc.), and some is simply used at whatever moisture content it has (keels).
Dry oak is everywhere, it's a staple of the furniture manufacturers, every lumberyard should have it. After a certain boat size english oak becomes unavailable commercially, so size matters. Larch good enough for planking is difficult to obtain, you need to talk to some scottish sawyer specializing in the species.

 

British Hardwoods at Keighley may able to help: Sawn Air Dried Oak Beams | Five Years Air Dried https://www.britishhardwoods.co.uk/sawn-air-dried-oak-beam.html
Also : Whitney Sawmills https://www.whitneysawmills.com/

There will be others- there are plenty of sawmills about, but the lead in times will be substantial, and it's not going to be cheap .

 

In my opinion, kiln dried wood is superior.

I went to school for traditional hand made furniture and design. My instructors were educated at the North Bennet Street School in Boston that does a feature every year in Fine Woodworking Magazine. They taught that air dried wood was the best way to go, but my belief is that kiln drying takes the wood below air dried levels which collapses the wood cells as much as they can collapses. Once this has happened, they don't fully recover when equalized to normal air. This reduces the size variance that the wood can experience when seasons change. This is just my opinion based more of thought experiments than actual experimentation. A few weeks sitting in the shop is always best.

-Will (Dragonfly)

 

I always use dry wood. One exception; if it needs extreme bending, but I let it dry after it's bent before I install it.

 

Furniture wood is drier than what boatbuilding needs, except for interior cabinetry. Kiln drying has the advantage of killing spores and yeasts because of the high temperature. For bending, including planking, the moisture content has to be relatively high. It is often necessary to soak the wood for days before using it.

 

Any wood destined to be bent is best not kd, air dried or green is better. Much depends on the bending need as Rumars put so eloquently.

Any kd wood that is going to be used in an outdoor build requires acclimating; which means brought to the equilibrium moisture content of the build environment. Or for an outdoor build; stored outdoors under covers from rain. Acclimating requires stacking or restacking the wood with inch stickers and those stickers needs common support lines. Some will ratchet strap the stacks even to avoid movement.

Acclimating takes two-four weeks. Even an indoor build should use acclimating, but it can be harder to find space for stacks of lumber in a small boat build. What you are trying to avoid are large swings in moisture content. Kiln dried lumber stored outside for a year by the sea will get to a much higher mc than the post kiln amounts.

There is quite a bit to consider if you are in a wet environment.

also, the butt ends should be sealed during storage or environmental changes

I suggest some reading. I don't have great references for you. But a fun book is Boat Building by Howard Chapelle. It covers wood construction in an overview form and has some basics on lumber.

 

https://www.fpl.fs.fed.us/documnts/fplgtr/fpl_gtr190.pdf

 

Looks like Whitney Sawmill can supply larch, oak, douglas fir, green, airdried or kiln dried.
A quick google for 'marine timber suppliers UK' will give you lots to go at.