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I have an old house that has the old full dimension floor joists that are fully 7 3/4 wide and varying between 2 3/4 to 3 inches thick.
I am doing a remodeling project where I desire to remove a small bearing wall that supports the 4 floor joists that I will be exposing. The 4 joists are 17 feet long. the small bearing wall runs perpendicular to the 4 floor joists approxamitely 6 to 7 feet into the span. I desire to remove this small bearing wall and move it back so that its approxamitely 2 to 3 feet into the span from one end. This would leave the 4 joists spanning approxamitely 15 to 14 feet unsupported across the remainder of the span whereas now, before removing the bearing wall, they are spanning about 11 to 12 feet across the remainder of the span. Is this ok?
My question, how far can such full dimension floor joists span before a bearing wall is needed under them? Can I let full dimension joists span 14 feet unsupported with no fear of sagging, especially since it only 4 of them that will lose the support?
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Don't know, can't say...but the span tables will tell you..
sounds like you got some heavy duty 2x8's spanning 17 ft, and that don't sound good...you got to do a load diagram and figure what you're trying to support...from the little info. you're giving , no one other than a betting man would give you a stand pat answer....describe it better or go see a local PE, they got families to feed too...
Good Luck !
*To answer your question, we'll need to know the species of wood, the grade of wood, and the spacing of the joists. We'll also need to know what these joists are supporting. Is it a second floor bedroom? a roof? snow load? are there any walls within this span in the floor above? If you can give the whole picture, I'll do a quick calculation and venture a guess just to give you an idea of whether it's likely to work of if it's not even close to safe. Then, if it looks likely, you'll know it's worth it to go see the PE and get the expert's opinion.
*Unless there was some sort of load bearing structure beneath your short wall the house seems to have other structural problems as well. You mentioned exposing the beams is this a detail?? if not check the span ratings for I-joists and see if you can sister the existing joists.Just an idea.
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Buncha young pups...From the sounds of things I would say that you should have no real problem doing what you propose. Span tables are somewhere between a mystic oracle and pure bunkum. BAsically, they provide a very conservative span based on an average piece of wood. Yes, if we knew what kind of wood the joists were and whether they had knots within 1 inch of the edge we might be able to come up with a "magic number" but this is bean-counter thinking.
Take a good look at your joists. I just built a 12x24 foot storage loft in Wyoming using rough cut full-dimension (and then some) lumber from a local sawmill, and I can speak from experience, this stuff made a much stiffer floor than normal construction lumber would have produced. I would trust the joists you describe to span the 14-15 feet that you propose.
I don't say throw the span tables away, but as soon as you are dealing rough lumber the span tables aren't much help. Use your own good judgement...nine time out of ten it will not let you down.
MSC
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......MSC......who you callin a young pup? ....thanks anyway...
Go back and read the query...he's increasing his span from 11-12' to 14-15'...and unless you're a mind reader, he hasn't given enough info. to even come close to making a recommendation..
......so much for common sense.... and you can use the span tables for rough cut....it's just that the building inspector won't accept them because the lumber wasn't graded...but you can apx. the grade... and enter the table with the species and be conservative in your application....that's where the "common sense" comes in.....
b but hey, what do I know?...
*What is everybody worried about. Some 2x4s and bubble gum would easily span that distance. It doesn't matter what the load is above the joist.It's well known that all buildings are exactly the same and scientific facts will never stand up against overwhelming guesses.
*I wouldn't go the 2x4 and bubble gum route without first checking the bubble gum adhesion tables.Rich Beckman
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I have an old house that has the old full dimension floor joists that are fully 7 3/4 wide and varying between 2 3/4 to 3 inches thick.
I am doing a remodeling project where I desire to remove a small bearing wall that supports the 4 floor joists that I will be exposing. The 4 joists are 17 feet long. the small bearing wall runs perpendicular to the 4 floor joists approxamitely 6 to 7 feet into the span. I desire to remove this small bearing wall and move it back so that its approxamitely 2 to 3 feet into the span from one end. This would leave the 4 joists spanning approxamitely 15 to 14 feet unsupported across the remainder of the span whereas now, before removing the bearing wall, they are spanning about 11 to 12 feet across the remainder of the span. Is this ok?
My question, how far can such full dimension floor joists span before a bearing wall is needed under them? Can I let full dimension joists span 14 feet unsupported with no fear of sagging, especially since it only 4 of them that will lose the support?