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   Guest_ | Mar 13, 1999 11:34pm | #1

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   That would be a good question for your building inspector, since codes may vary from place to place, but around here a 2x12 spans a max. of 15'7" at 12" o.c., 14'9" @ 16" o.c. and 14'1" @ 24" o.c.... 2x10 goes 13'8', 12'11" and 12'4"... the minimum for a crawl space here is 23 5/8" if there is any plumbing or equipment, otherwise I suppose you could build it as low as you want, except you'd want pressure treated framing if you get too close to the ground.

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   Guest_ | Mar 13, 1999 11:40pm | #2

   *Ross,You're not quoting any span table I have ever seen...I like to build floors stronger but haven't yet used 12" oc. 14' for 2x10 all day and all night...2x12 16' even though I had an architect go 20' on his own spec home.Where is home?J

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   Guest_ | Mar 13, 1999 11:51pm | #3

   *Quoted from the brand new Ontario Building Code, rewritten by the corporate elite developers looking to get that extra little $200 in savings on each of their 2,000 homes by underbuilding... I've never built a floor to the code minimums yet, and you're right, those joists sure would make for a bouncy floor, but it passes the code here!

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   Guest_ | Mar 13, 1999 11:57pm | #4

   *Ross,I implied that your spans were overkill, not underkill???J

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   Guest_ | Mar 14, 1999 12:13am | #5

   *Jack, Strong floors are one thing people can feel that tells them something about the quality of your construction. Most everyone will jump up and down on a new floor and very knowledgibly (where's the spell check???) say "gee, feels like a good solid floor"... humour them and give them what they want, something that feels sorta like a concrete sidewalk, costs so little to see them so happy... I was told by someone a long time ago that a 2x10 goes 10', a 2x12 goes 12', etc. It's wrong, but what the heck, it beats any code anywhere that I know of.Ross

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   Guest_ | Mar 14, 1999 12:15am | #6

   *Ross,You're being silly....enjoy.J

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   Guest_ | Mar 14, 1999 12:35am | #7

   *You can get even cheaper if you use bridging... but then again, you get what you pay for.

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   Guest_ | Mar 14, 1999 07:43am | #8

   *Ww must like bouncing around here in MI. Every house I get a huge atack of 2x10x16'. I don't usually have to cut anything off of it. That makes the span 15 4. I might have to double every other one. No bridging. 16" oc. Doug fir.Blue

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   Guest_ | Mar 15, 1999 12:57am | #9

   *Ross et al. The 1997 Uniform Building Code (UBC) and the 1996 BOCA code read essentially the same regarding how close to the earth framing members are permitted. UBC Section 2306.3 " When wood joists or the bottom of wood structural floors without joists are located closer than 18 inches or wood girders are located closer than 12 inches to exposed ground in crawl spaces or in unexcavated areas located within the periphery of the building foundation,the floor assembly including including posts, girders,joists and subfloor shall be approved wood of natural resistance to decay as listed in Section 2306.4 or treated wood." The BOCa codes reads essentially the same. Spans. As you well know floor joists spans depends on live and dead loads, spacing,modulus, Fb and species and grade. The 1995 CABO One And Two Family Dwelling Code (OATFDC) allows a 2x12 @ 24 "oc, and live load of 40 lbs and dead load of 10 lbs, to span 16'-3" if it has a modulus of 1.3 and an Fb of 1380. A Select Structural SPF @ M= 1.5 and Fb = 1440 would work.Bridging does not work. The most recent research out of the Canadian Maratime Provinces University developed a method to make it work. Run a metal strap under the bridging. Here on the east coast, especially in New England, furring or strapping of the ceilings is a common practice. So when furring out the ceiling make certain the strapping is directly under the bridging.Another way to strengthen flooring is when using oak flooring glue and nail it parallel to the floor joists.what you now have is a composite floor which is much stronger and stiffer than if the oak flooring were installed perpendicular to the floor joists. GeneL.

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   Guest_ | Mar 15, 1999 02:32am | #11

   *I believe you, Gene! Reminds me of the Ontario New Home Warranty exam, I got all the questions right (not a great feat, since it was an open book exam), and the woman who graded it told me a lot of people fail the exam because they don't answer the question the way it's supposed to be answered, that is, what does the code say the answer is? Some people just pick the thicker joists or wider spans or whatever then try to argue that their answer was superior to the one they called correct. They fail the exam anyways. Did I just fail the test here, or what? Who cares, it's Sunday, what am I doing thinking about this stuff anyways today? Off in search of a life......

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   zebeul | Mar 15, 1999 02:32am | #10

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