Timber choice for greenhouse and sheds

[Awac]

@Awac thanks for that. useful to know. i assume we're looking at it as a treatment as you describe and a final finish ie. the blurb suggests it cannot be painted or stained over?

I have never tried painting over it, I try to leave the wood showing where I can. You can buy a stained version, or maybe try mixing in some pigment of your own?

 

[topchippyles]

Use larch and no need to treat it either if you prefer natural look. Good for 20 years and i am lucky enough to have a good supply locally to me.

 

[Billy_wizz]

A little tip if you go to a timber yard and buy treated timber and select from the pack , don't be tempted to pull off the top couple of layers to get " the good stuff underneath " the timbers on the outside of the packs tend to absorb more of the treatment and those towards the middle less and also those from the middle can contain a fair bit more moisture as it takes a long while to dry out inside . If you do pick your own timber do yourself a favour and restack what you don't want , trust me when i say ,you will get more help from the yard staff next time you visit ,leaving a mess on the deck will have you're name on the naughty list and it is suprising how quickly all the staff become to busy to help

You leave a mess at our yard sorting through packs you don't come back period! You need to work round the air gaps for the best chance of uptake but generally the wetter heavier bits are the ones that have taken the most in so take longest to get the water back out

 

[Benpointer]

I am looking to build a 'cedar' greenhouse.

I say cedar, but Canadian Western Red Cedar has got ridiculously expensive so I'm now looking at alternatives. It would actually be cheaper to build the frame from European oak but I fear it will move far too much and cause issues with the glazing.

I might look at UK grown WRC which is not as durable but probably durable enough (I plan to cap the rafters with aluminium capping and take care to avoid water collection spots). I can get green WRC cedar from a local sawmill but how long would I need to let it air dry? The posts and rafter are likely to be 90 x 45mm section, so the old rule of thumb would say if I start with 2" boards I need to leave the two years. Then again the green UK WRC I have used in the past for featheredge cladding has been remarkably stable as it dried.

It's all getting a bit complicated - I can see why people have aluminium greenhouses!

Any thoughts suggestions?

 

[johnnyb]

one year per inch is probably over the top on softwood. I've had large chunks of green larch dry in 6-12 months.