Despite the popular consensus to design wood diagrams as flexible, in most cases with new construction they are almost always rigid. With irregular shaped buildings the most common method of handling diaphragm horizontal offsets is by using collectors with drag strut connectors to the shear...
This past winter Charlotte had a whopper snow storm with almost 6 whole inches of accumulation. I am now looking at my second roof truss failure as a result. Both situations are identical. Churches with scissor trusses spanning 46 feet, both built in the mid-90s. The truss company who did both...
I've always had difficulty finding the allowable bending stress of plywood and OSB in an application where it is to be used as a gusset plate. I can find stresses for its normal floor application, but I wouldn't assume them to be the same for orientation in a built up beam situation. I've...
So I'm designing a boathouse that has 8" diameter wood piles. The piles will be driven in at a 6 ton capacity. Assuming a fixed base, the piles will be very tall to support an upper story deck with a boat slip below. I'm concerned about the sway and want to check for the need for bracing. I can...
Has anyone gone through the tedious process of analyzing / designing connections for overhead plumbing pipes as related to seismic forces? Being in NC, we've only had to deal with basic building seismic design. We've been hired to analyze the plumbing connections and 50 gal. water heater for...
We have a legal disclaimer in our contract that essentially states that the Client agrees to not hold the engineer financially liable for more than the amount of the design. Our lawyer and state board said that it holds up if the statement is agreed to and signed by the Client. Now what if the...
I do a lot of engineering for the residential market. I often come across brick and natural stone rubble veneer arches. In the past I have used my own rules of thumb based on basic analysis and knowing what I've seen work and fail in the field. Now I am in a position where the architecture...
Has anyone noticed the rafter span tables in the IRC and AFPA seem off? I use the horizontal projection and all the factors from the NDS. Although bending seems close, deflection seems way off. For instance, the IRC shows 22'3" for 20/10 loading of 2x10@16" SPF#2 @ L/240. I calculate a...
I too have recently become involved with determining a repair for a 100 year old, 3 story brick building. Here's the situation: An old theater adjacent to the building in question was demolished. They decided to rip down the wall of the theater that was against the wall of this building. In...
I am designing a gusset plate with plywood in a beam application. The gussets will go along the sides of the beam (oriented vertically). I'm using APA's D510 technical article to determine the bending stiffness and bending stresses. Unfortunately those stresses are only for bending about the...
