I am building a swing set for my first “big” project. I had to order the lumber – I couldn’t hand-pick the pieces because I don’t have a truck that is big enough to transport them. So I ordered five of the legs (12 ft 4×4 doug fir) in case one had a problem. Four came with heart wood. All of them are checking. Two of them are twisting and one of them is bowed. So I don’t have four good legs. But can I use them? I am ok with the look of the checking. And I can kind of hide the back legs of the swing set so it won’t bother me too much if they look strange. But I am worried about strength. I want this swing set to be safe. Is it ok to use the checked wood? Is it ok to use the twisted 4×4 or the bowed 4×4? Would one of them be better?
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If your structure fails it will not be because of the wood. If the design and workmanship is good those fir 4x4 will be just fine.
Thank you! Good to know!
The lumber company did you wrong. Seems like they gave you whatever was randomly on the pile. For a swing set I think you will be fine, but I’d look for a significant price break. It’s worth a try.
Why? I've been a contractor for nearly 50 years and those look like run-of-the-mill 4 x 4's to me. Of course they gave her what was randomly on the pile, what else would you expect?
I wasn't really expecting the employees to carefully pick the wood like I would if I could be there. That's why I ordered extra - to replace one if it wasn't usable. I just wasn't expecting to have quite so many problems.
What you got are typical pine 4 X 4's. They all check and split, some worse than others but they all do it and it will get worse as the years go by. They all warp and bow, the longer they are the worse they do it. Even if you use relatively straight ones they will bow when used as legs on a swing set, especially if you plan to have them 10 or 12' out of the ground.
If you need better buy clear fir or redwood in 4 X 6" to reduce the bow but you can expect to spend a lot of money on them.
Nothing at all wrong with those 4x4s, don't worry about the checking and splitting from a structural perspective. Happy building!
For longer life for the swingset, seal the end grain with West System epoxy, especially the ends that make ground contact. Also consider rounding over the edges of the 4x4's to minimize splinters in the hands of the little ones that will be enjoying the swingset!!!
Best wishes!!!
I'd get a 1/2" round over bit and route all the edges. Have fun!
For whatever reason, I have found that 4x4 is always the worst dimensional lumber until you get to a very expensive grade.