Saturday, October 18, 2008
Not wanting to waste resources for the landscaping, I came up with a design that used as many local and recycled materials as possible. Starting with the entryway, I built a platform out of treated lumber (leftover from the barn framing) and covered it with old concrete slabs that we unearthed during the site excavation last year. The platform was skirted with more of the old bricks from the original barn. Next I dug a curved pathway leading around the silo, and partially filled it with 'fines' from the nearby iron mining operations (I believe it is created during the blasting operations, but not sure). Then I finished the pathway using Urbanite (concrete pieces from old sidewalks) that I've been collecting over the summer from various places. The spaces between the 'stones' were filled with more of the mining sand. Due to the irregular thickness and shapes of the urbanite, it took a tremendous amount of time to build it, but the end result has a nice look. Finally, the ground was covered with a layer of wood chips that came from the city work crews (they run the branches of cleared trees through a wood chipper, then haul them to the burn pile). Other than the roll of landscaping fabric that went under the mulch, everything for this project has been recycled and locally-collected. I figured that I used about 2 cubic yards of recycled urbanite to make this pathway, which helps to offset the 15 cubic yards of concrete required to pour the barn slab last year. The ground will remain pervious and we won't have any more grass to mow than we did before. In the spring, we can plant some flowers and schrubs in the mulched area, but for now this will have to do (winter is coming!).
Wednesday, October 15, 2008
Since I was determined to use 1/2" material in the upper story of the silo, my final drywall bending challenge was the most difficult. To get the radius just right, and keep the sheet from breaking, I built a form out of leftover drywall and lumber scraps. Then I robbed the house of several bath towels and used them to saturate the drywall sheets with water. After sitting for an hour or so, they easily sank into the shape of the form. Next, I screwed some crossmembers into the form to hold the drywall in place while it dried.
A perfect fit...now that I've become an expert at this, I should never need to do it again.
Because the barn was too tight to produce accurate readings when they were here the first time, Minnesota Power returned to complete the air infiltration testing with a more precise blower door assembly- the results were as good as we could've hoped for. The magic number measured in this test is referred to as CFM50, which represent the amount of air leaking through all the gaps in the building when it is under a negative pressure of 50 pascals. The smaller the number, the better. Most houses today, being of older stock built before we knew much about air sealing, are very leaky, so CFM50 values of 1.0 or larger are common. A "Code" house built today should be .50 or less. To meet the minimum Energy Star requirements, we needed to be .25 or better. The more stringent Energy Star Tier III requirement is .15 or better. To satisfy the even stricter PassiveHaus standards (arguably the most stringent energy-efficient building standards on the planet), the barn's CFM50 would need to be under .08. That said, I was thrilled when our building measured .05 in this test- one of the tightest buildings they have ever measured...we did it! Since the CFM50 value represents the air infiltration per square foot of building size (in other words, the barn was .05 cubic feet per minute airflow per square foot at 50 Pascals pressure), it can then be converted to the ACH50 (Air Changes per Hour) number, which takes into account the total size of the building. This number represents how often the air is exchanged through the building due to uncontrolled leakage. Obviously, when you are trying to conserve precious heated air in our brutally-cold winter climate, the lower the number the better. the ACH50 value for the barn was 0.4, so we bettered the PassivHaus requirement of 0.6 ACH by 33%. This is exponentially better than many of the older homes in this area, and a substantial improvement over even the well-built new homes today. So what does all this math mean? Minimal heating system requirements, low heating costs, and a comfortable indoor environment...we'll take it.
Friday, October 03, 2008
I spent the last couple of days working on our rainwater collection system- a great Spring project that happens to be about 5 months behind schedule- just in time for freeze-up. The big delay was finishing the silo exterior so that the rain gutters could be installed. Fitting the gutters around the silo proved to be a challenge- nothing seems to come easy in the life of a bad-boy barn builder. A couple months ago, while prepping the silo for stucco, I needed to find a way to divert the water away from the roof-wall interface and keep it from working its way under the stucco. After pondering it for quite awhile, I modified a section downspout and attached it to the silo wall. Then I lapped the step flashing, housewrap and foamboard over the top of diverter piece to make it waterproof. Once the stucco was applied and the scaffolding moved out of the way, I was finally able to install the gutters and downspouts, which look like this: Now how to collect the rainwater? Actually, collecting the water is the easy part- the problem is dealing with our 6 months of freezing weather that has me worried. Usually I can find alot of useful problem-solving information via our good friend Google, so I spent several sessions searching for examples of rainwater cachment in cold climates. No luck. The only suggestion I came across was to "drain and remove the rain barrel in the fall." The system I have designed aims to collect and store 100% of the available rainwater, which means we'll have ALOT of barrels by the time this is all done. Removing them all at the end of each season would be a nightmare- not just the work, but also the logistics of storage and dealing with downspout extensions, etc. Call me lazy, but I want to make a system that can stay in place year round. So, without any good examples to work from, I'm just going to experiment. Using recycled plastic barrels that we repainted to match the barn, I started by cutting a hole in the lid and covering it with window screen (held in place using a metal stovepipe flange). I terminated the downspout directly over the barrel here.
Each barrel will sit on a stand to keep the collected water high enough for gravity-feeding to all the gardens. The stand also gives me room for the plumbing connections below the barrel. I drilled a hole in the bottom of the barrel and threaded a 2" fitting in place. Using PVC fittings, I installed a "tee" leading to a faucet that I mounted off the front of the stand, then below that a shutoff valve before the pipe goes underground. Below grade, I transitioned to ABS pipe, which will continue around the perimeter of the barn and connect all of the rain barrels in series. By maintaining the same height across all of the barrels in the system, they should fill equally regardless of where the water is coming from...
With the first two barrels installed, I decided to quit for the season. I can drain the underground line and close the hand valve to keep them from re-filling during the winter. I plan to remove the hose from the tee fitting so that the barrel can self-drain should it rain anymore before winter. I'm not sure what will happen during the snow season- will melting snow from the roof fill the barrels with water, causing them to freeze and rupture? Or will they survive here at the North Pole? I'm not sure. Any suggestions????