What's the maximum span for a 6x6 beam with no load support?
Asked by RandomUser312
I'm considering using a 6x6 beam to span approximately 15 feet by 9 feet without any support in the middle. Is this a feasible option, or should I go for something else? I want to clarify if the 6x6 can handle that span on its own.
Answers
Using a 6x6 for that span is not ideal. A beam that long will sag quite a bit over time due to its weight. Instead of a 6x6, you might want to look into double 2x10s. They provide better support without the sag issue.
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If there's no load, the 6x6 might hold but expect it to sag a bit under its own weight. I’ve done something similar with 4x4s, but my beams bent a little before I switched to 4x8s with steel brackets. No more bending issues since!
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Generally, the rule of thumb is that the depth of wood should be span/2 + 2, which would suggest a minimum depth of about 9.5" for a 15' span. A 6" beam won't cut it here, especially if it's unsupported. Why not use 2x10s instead? They provide better strength due to their design.
AestheticDude42: I went for the square beams for looks, but now I see that's not the best way for structure. You definitely want depth for strength.
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BuilderGal88: Exactly! A double 2x10 setup would give you about 15' of strong support. Plus, they're lighter than a 6x6, so you won't have to worry as much about bending.