That's interesting that you mention the 5 psf reserve capacity due to roof live being 20 psf and snow being about 15 psf. We have the same snow load here. And I have seen that used by another engineer as justification for solar panels on a roof before. He stated in his letter, and I'm...
Thanks, I have seen a couple drawings that specified an area load and indicated the self weight of the truss as a separate additional load, but most of them do not get that specific. I guess I'll just have to assume that the self weight must be subtracted from the design loads in order to be...
I do have the shop drawings for one of the buildings. It says the truss was designed for a top chord dead load of 5 psf and a bottom chord dead load of 5 psf. Do you think those numbers are in addition to the self weight?
I am doing a lot of roof evaluations to determine if existing structures have enough excess capacity for roof mounted solar arrays. I keep running into buildings with pre-manufactured wood trusses. Fortunately, I often have access to drawings that indicate the loads that the trusses were...
I'll have to think about that one for a minute. Not a bad idea. Just make the shear lug pocket bigger, cast a sleeve in the pier made out of the same material as the thermal block and grout in the shear lug within the insulated sleeve? Could work.
I'm not quite sure I follow your comment suggesting that the shear is taken out by the compression column of the braced frame. The shear is applied at the uplift column. How does it get to the compression column in order to engage the friction of the Fabreeka thermal block?
In researching the...
KootK - Part of my issue is that I have net uplift on most of the columns that need to resist shear, so even a product like Fabreeka that may have published friction values, wouldn't do me any good. But, I will definitely take a look at Fabreeka to see the friction values they publish.
DETstru...
Decided to go with an HSS4x4 shear lug. In talking with the thermal block manufacturer, they said this is something they see often. I never could get to a comfort level with resolving the force through the slab since the slab sits on insulation and a vapor barrier and so there isn't much...
The AISC Design Guide #1 - Base Plate and Anchor Rod Design, Section 3.5.5 titled Hairpins and Tie Rods says: "The friction between the floor slab and the subgrade is used in resisting the column base shear...", and it says "...a vapor barrier should not be used under the slab". I take this to...
Unfortunately, at this point I'm kind of at the mercy of the refrigeration consultant that the client hired to be their expert on this subject. They say 10" blocks from the Shadco manuf. are what we need to use, although I may push back on that 10" thickness. They like to use the polyurethane...
Yes, we have 6" underslab insulation, glycol heating coils under the insulation, and they want to use a polyurethane thermal block under the columns provided by a company called Shadco. However, I still don't see the load path for a 25k lateral force when you have a 10" gap between your...
I am designing a freezer structure for the first time and was just informed by the freezer consultant that there needs to be a thermal block under the baseplate of each column in the freezer. Interior columns need a 6" thick block and exterior columns need a 10" thick block. This is not a big...
