Went fairly slowly as first time and somewhat difficult to cut and fit as footings are not square or straight and trying to get air tight. Not entirely sure at this point it was worth it (expensive stuff). Talked to ducting contractor and he now does not want to do the work if I go with the engineers duct & HRV sizes (unless I am absolutely stuck. He doesn't do his own tinning so can't make the connectors for the 8” (or 7”) ducts (would have to buy from other contractors). He says that is what the contractors who work with the bigger ducts do (make their own). Also says the HRV and ducts are too big (second contractor to tell me this.. they are using approx. rules of thumb, i.e., so many cfm's per bedroom, kitchen etc.), but the engineer says show me the calculations. ASHRAE's (American Society of Heating, Refrigerating and Air-Conditioning Engineers) simple formula for minimum ventilation (also referenced in Joseph Lstiburek's, (from Building Science Corporation), book Builder's Guide to Cold Climates), also indicates it is too big (7.5 cfm/person plus 0.01 cfm/sq. ft of conditioned floor space. Stretching it to include basement, mudroom and Narnia would still have less than 3000 sq ft. and assuming it is a minimum so go up by 50% to 11.25 cfm. 11.25/person+3000/.01 = 11.25/person +30. The Lifebreath 300DCS recommended by the engineer is specs. are 250 cfm at 75 Pa ESP (External Static Pressure) so would have to have to 19.6 people to reach this (apparently a pretty big party.) Not sure what to do at this point (more research??!!**#!!). Concrete contractor says won't be able to backfill basement until aprox. next Wednesday.
Here are some more pics. At the bottom are rammed earth wall samples, approx. 12" X 3" X 6-10"high I made last October, using different combination's of material (soil) (local material with different %'s of portland cement and some with added gravel). They have been out in the elements since then and have stood up pretty well. The wall in the house will be off the ground and be protected by a 2' overhang so I am optimistic it will stand up well. For each soil combination I also made a rammed earth column about 6" tall by 3" diameter and had it crushed at Stantech's geo-technical lab to see which ones passed the required pressure (4MPa) as specified by the structural engineer (unfortunately not all did). I am following the procedures in David Easton's book " The Rammed Earth House". Although this is probably the most experimental aspect to the house, ~ 3billion people live in buildings made of dirt (probably not so many in the first world), so I thought I would give it a shot. Many have stood for hundreds, if not thousands of years (shouldn't we build all buildings (and other things) to last this long? Designed for longevity, easy repair and upgrading if required, maximizing the use of real resources (oh no, wouldn't we wreck the economy :-(. As usual I can't resist the side comments. Keep at it I say and hopefully they will start to question things...? ;-) This has turned into a long post.
Here is a video on a rammed earth house.
David Suzuki video on Rammed Earth House
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| Basement Delta MS with 2" EPS Type 2 over. Will lay wire mesh and 4" of concrete over this. Root cellar is dirt with ~1.5" of gravel over it to keep the surface dry. The dirt below will be saturated with moisture to maintain near 100% humidity. |
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| Pneumatic tamper. Bought refurbished from Detroit as can't rent anywhere here. Need 100cfm at 90 PSI to run this thing (e.g., a tow behind a vehicle compressor). Thankfully I can rent that here. Masonry heater kit shown on the right. |
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