![]() That is not to say that nothing can go wrong or that it does not need to be looked at carefully but to ignore performance data will, in the long run, create more problems than it will solve. How well a member has performed in the past, especially if it has been fully loaded, is an important and generally reliable indicator of future performance. ![]() Modern span tables for solid sawn structural lumber are based on empirical performance of rafters and joists in the field. Calculations are also based on load-testing specifically testing is required to obtain reliable engineering properties for use in making calculations. If we reject load testing in favor of calculations that makes no sense to me. If a structural member has, in effect, been load tested, I consider that fact to normally be a reliable basis for forming an opinion. The question is what is a generally reliable basis for forming an opinion. These are visual inspections and the question is not a matter of being absolutely certain as to the safety or adequacy of a structural member or arrangement. There is a brutal reality to that opinion. "the length of time any structural element has been standing has absolutely nothing to do with it being adequate or safe". !(upload://ssT9V5t45yjlgXqiFRXL04eXtqw.gif) They usually get the point after changes and delays. As a designer and municipal inspector also, I see too many framing contractors just winging it on the engineered lumber. They should also call the person responsible for the design to clarify anything that is unclear. ![]() There is a brutal reality to that opinion.įramers, call your lumber dealer and ask for help ! " the length of time any structural element has been standing has absolutely nothing to do with it being adequate or safe". Fortunately, the house was condemned and posted, so nobody was there at the time it collapsed. Part of a house house collapsed about 2 weeks after I issued that report. even though it had been previously fully loaded. I have seen it first hand, and in one case after doing some calculations warned of a probable collapse of some main framing members in a house. A fully loaded structure that was not done correctly can just barely support that load, and at the same time weaken the structure to the point where the next full load will cause a collapse. I agree with ya in general, except for that one. If the support has been fully loaded in the past, which is normally the case in a resale house, and there is no apparent performance issue, it is probably okay even if it was not done to the book. I am absolutely amazed sometimes by how much thought goes into doing things wrong However, those prescriptive model code provisions can not be applied to engineered lumber (like LVL's and I-Joists) which requires a case-by-case evaluation due to the higher capacity and special requirements.įor engineered lumber, I think the best thing for an HI to do is look for visual indications of problems, and defer to an SE as Mike noted for anything beyond that. Those prescriptive provisions are fairly easy to apply for someone who understands framing. There is a big difference between “conventional lumber framing” and “engineered lumber framing”.įor conventional framing with typical solid sawn wood members, there are very prescriptive requirements in model building codes like the IRC related to allowable spans and suppport requirements for things like wood joists/rafters and wood headers/girders. Never guess when installing a support beam.This post was automatically imported from our archived forum. They have the skills, knowledge, and experience to ensure that the job gets done properly and safely. So, that means a 2×12 beam can go 12 feet, a 2×10 beam can go 10 feet, and so on. ![]() If the joists being supported span 12 feet and have no overhang, then you can use a double-ply beam spanning the equivalent of its depth in inches. In order to estimate beam span, there is a simple method to follow. Related Guide: How Far Can A 6×8 Beam Span? How Big of a Beam is Needed to Span 12 Feet? ![]() A good rule of thumb: the larger the deck, the larger the joists. A 2×10 can span 15 feet, a 2×12 up to 18 feet, and so on. So, a 2 x 8 beam is able to span 12 feet without support. Generally speaking, joists that are spaced out at 16” intervals on center are capable of spanning 1.5 times in feet the depth in inches. How Far Can a 2 x 8 Beam Span Without Support? The installation of support beams can get to be a little more comprehensive, so here are some supporting questions about beam length, span support, and more. ![]()
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