I understand the theory of warping - why it happens etc, not so sure on how to prevent it I spent a good 20 mins picking through the kiln-dried 4x2 in Wickes the other day trying to find 2 pieces that weren't bananas. In the end I managed, but then I was concerned that they'd warp before I could use them. I assume that now they're jointed and glued in a frame, treated and painted that they're likely to stay in shape? Then I had some treated 6x2's that I bought last summer to use as concrete shuttering with a mind to reuse as support for future decking. Straight when bought, kept outside and stayed straight all last year, stored with stickers allowing air circulation around over winter. Pulled one out yesterday and it's quite badly twisted. Reason I'm asking is now I'm thinking of buying some more 3x2 or 4x2 to use as support for a home-made workbench. Found a series of videos based around a bench with a ply top mounted on 2 parallel 4x2's. I can't see this is enough to stop the wood from warping? I know that the choice of wood makes a difference - CLS is cheap, but I'm guessing prone to warping? Is this the only solution, spend more on the wood in the first place?
Buy wood from a ‘proper’ timber yard if your lucky enough to have one near you Generally better quality, wider choice, stored properly, staff know about timber and often cheaper than a ‘shed’
Last summer I bought £500 worth of 6x2's from a proper timber yard. I left it out in the garden for a couple of weeks - loosely stacked - and when I got around to starting the decking most of it was twisted beyond use. :-( Edited to say it was all perfectly straight when it was delivered - I know because I did a "dry fit" of the deck frame and it all looked great.
I think it’s just the nature of the beast, just have to use as quickly as possible, you’re never going to be able to perfectly match the previous storage conditions are the timber yard etc. Also treated timber tends to have a lot of moisture in it anyway and be of lower quality. With a bit of skill timber can be straightened out when fixing.
So is there any guide to how much joining/fixing needs to be done to a piece of wood before you can be confident it won't warp?
for laughs and giggles I'm making a shed framework out of 'greenish' cedar ( was laying around for 4 months before being milled) It'll be interesting how much movement there'll be on the joints. Some with mortice and tenon with pegs and some rabbet jointed and fixed with annular nails. Also how much splitting and warping there'll be. If it falls down at least I've satisfied my curiosity if it can be done or not. So many different opinions on whether green timber can or cannot be used
A golden rule of carpentry: buy your timber as straight as possible, and fix as soon as possible (the next day). It makes me laugh when I see advice such as: "Leave the softwood that your going to use to make a frame, in the room to acclimatize, and reach the same moisture content." Do this and all you will have is bananas and propellers. Buy good quality redwood from a builder's/timber merchants, not whitewood.