Friday, January 20, 2012

ClearSense Update: Reuse – Big and Small

It recently occurred to me that in the midst of moving at a million miles an hour on this project, we have only been updating our BuildSense|Studio B “on the boards” and “under construction” facebook page with images of the new building during construction. This is truly unfair, because it is only half of the story. For those of you unfamiliar with Downtown Durham, you may not be aware that this building has had a previous life. Originally constructed in 1945, the one story masonry building served as a farm equipment and tractor service center. In the early 1970’s it became the “Tire King” and has been largely recognized as such for many years until they relocated up the road two years ago.
That’s where our story of reuse started. Though the building was filthy, dark, and dank, and reeked of old oil, we observed a masonry shell that had not endured significant cracking or damage after certainly settling and shifting to its maximum over 55 years. We were happy to know that we could reuse this existing structure to support the needs of raising the roof and adding a second story.
Interestingly, the decision to add a second story prompted numerous ideas for the best manner to achieve it. The roof was comprised of 2x10 wood joists supported by steel beams. While this certainly supports a typical residential floor load, the commercial loading requirement would have required additional joists and still flexed underfoot. Furthermore, the exposed ceiling would offer little for sound insulation from the first to second floors, nor have any fire resistance value. Some combination of insulation and gypsum board ceiling would be required. The topside would surely require an additional layer of plywood to smooth out the surface after the old membrane roof removal destroyed the existing underlayment. Then we would be required to finish the floor with a final floor covering. Is this all worth it; especially knowing that it would continue to have the 3” slope over 50 feet (the slope of the old roof)? The answer for us was “no”, and I am very pleased with the decision.
We removed all the old wooden joists and salvaged them on site. We installed new infill steel beams between the existing beams and columns and added a steel deck above. We poured a composite concrete slab from 5” to 8” in order to remove the slope. Additionally, it serves to structurally strengthen the existing steel and provides a structural diaphragm for the overall stability of the entire building. There is absolutely no bounce in the floor. It carries a one-hour fire resistance rating. It provides great sound insulation. Both the underside of the steel deck and the sealed concrete floors will serve as finish surfaces. The moral here is that sometimes striving to save certain items, though it emotionally feels right, is actually the wrong decision.
So how did we get back to feeling great about both the new concrete floor and removing the old joists? We stored the joists on site and have used them for infill framing and blocking for interior non-structural framing. Additionally, we have made use of them in a rather non-traditional manner by designing and building our new main staircase of the repurposed material. Members of our skilled team, including George Thorpe, Bradley Yoder, and Scott Metheny have been transforming the old lumber into a new feature. In a unique manner, the new stairwell will tell the story of the old building every time a visitor traverses the stairs. (Below, Scott stands on one landing laid out in the shop with treads in the foreground).

Saturday, January 14, 2012

ClearSense Building December Update

December saw lots of changes at the ClearSense building on Rigsbee Ave in downtown Durham. We started the month with the new steel frame, roof, and floor slabs in addition to what remained of the exterior shell of the original single story building. We are very pleased with our choice of roofing panel. The R-42 insulated metal panel is both super insulated and aesthetically pleasing on both surfaces. The underside will be the finished ceiling to the second floor interior space. (see photo below)

By the holiday break (at our required pace for this project, none of our team took much time off), one interior stair was roughed in, plumbing, mechanical and electrical systems were at 50%, storefront window frames were installed, and some of the second story siding work was completed. Most prominently, the wind turbines and photovoltaic array are up! (see photo of the ClearSense rooftop below) These systems combine for a rating of approximately 35.5 kW to power the building of just under 12,000 square feet. The turbines are quite prominent, practically a beacon of clean energy generation. We're very proud of them - are they the first building mounted wind turbines in Durham, in the triangle, in the piedmont? Please let us know. Unless someone tells us otherwise, we'll take credit for that as another of many "firsts" in our local building industry (see our website “Recognitions” page for more).

Our goal is that the building itself will be constructed to be approximately 50% more energy efficient than a typical existing commercial building of the same size and use and that the clean energy generation will provide approximately 37% of the remaining power needs of the building. Though our team only designs and builds energy efficient and certified "green" buildings, we were able to exceed our regular standard and install the clean energy generation systems with the help of a grant proposal accepted by the North Carolina Green Business Fund. We are very pleased to have established this relationship and thankful to the NCGBF for their assistance. Stay tuned for more on the innovative work at 502 Rigsbee Avenue.