Submitted 1 year ago by nottelling@lemmy.world to [deleted]
I don’t think wood shrinking/movement is to blame here at all. With single attachment at each joint and no bracing, there’s nothing stopping the whole thing from “racking” e.i. going from a rectangle to a parallelogram. You need diagonal bracing.
That design is asking a lot from wood. You could do it with metal, but wood needs bracing.
Have you considered adding metal L brackets?
Woodworker here. Building with "wet" wood will always result in some wood movement. For exterior applications, wood with around 9-14% moisture is reasonable. For interior applications, more like 6-8%. You can get moisture measuring devices to give you an exact reading.
Green treated wood is not great as most box stores will not allow it to dry properly before putting it up for sale. You can plan for this will corner bracing and such, but it will move on you if too wet. You can find stacks in the lumber yards that are drier than others which can help. Another option for exterior applications is to use kiln dried wood such as cedar and then apply a good sealer to it. If you really want to use the green treated stuff and it's too wet, stack it with shims between the layers and allow it to air dry until you get to the desired moisture. That should minimize the movement after building with it.
There is a good article here.
Looking at other kayak/canoe stands you need braces or angled shelving.
I’ve never known wood to shrink
There’s lot’s of people learning in this thread.
Untreated lumber will soak up water and swell, the dry in the sun and shrink. This process will allow natural twists to reassert themselves and stress and strain will warp into the wood.
Right, so how do you account for that in the design? In my photo, I didn’t account for it at all. The square cuts have changed and it’s failing. I can resolve it with braces as suggested, but now I’m wondering if those braces will change and it’ll go out of square again.
FewerWheels@lemmy.world 1 year ago
Based on this photo, it looks like it is failing in shear. It’s not a wood problem, it’s a design problem. The upper joint on the far right in the photo has clearly rotated and not a single brace for shear is visible. Think triangles and fix the design. It looks like this could be saved
brygphilomena@lemmy.world 1 year ago
Yea. Square it up and add braces.
intensely_human@lemm.ee 1 year ago
Braces will intersect with the boats. Instead it should be anchored to the wall at the top.