Get to the point: Clarifying structural loads on construction drawings
Eric Tiffin our magically talented Project Manager brought up the idea of writing about point loads this week. My first thought was that there may not be much to write about with this topic. He convinced me otherwise.
Ever get a call from a framer wondering where a header is going to bear? How about a failed inspection due to lack of blocking? Do your framers ever have to make additional trips to block for point loads? What would happen if a load was missed in the field and not properly blocked? Often large point loads are brought to bear upon a bond board yet never sufficiently blocked to the foundation. Even with structure being the most important element in framing a house this kind of stuff happens far more than it should. Talk to any Project Manager and he/she will tell you that these issues can occur on a daily basis.
With headers, beams, girders and the like, a house is full of point loads. A point load is an area where the structure is transferred vertically to the foundation, a horizontal beam, or a bearing wall. These vertical loads are typically picked up by studs or steel columns. Try this - walk into a garage under frame and look at the Garage header. You will see a number of studs holding up the large Garage beam spanning the door opening. How many studs should be holding up this beam - three, four, five? Without a plan indication of the point load detailing the structure it is anyone's guess. The decision typically rests in the hands of the framer. Big deal right? You bet. If you have too many studs, then lumber is being wasted, if you have too few - yikes.
Point loads should always be indicated on the construction drawings. Make this part of your design checklist. It will save time, money and aggravation. You will also be able to avoid that embarrassing little hassle called structural failure.