Three questions / possibilities: 1. Has anyone tried using flashing and tar -- instead of tape -- on seams in permanent installations? I remember suggesting this a few years back and recall having seen others passing similar suggestions around. Has anyone actually tried it? Any long-- or short- term field results to report?
2. And, Cody, re: OSB's water permeability: Do you think painting the boards with exterior paint and tarring their edges would solve that? Or is the stuff just too porous to effectively seal? An alternative to roofing tar for flashing (and for coating plywood or OSB board roofing panels) might be the more expensive, white "Snow Seal" roofing sealant which supposedly is more elastomeric and certainly, more attractive than tar-fiber roofing coatings. 3. Any idea how much thermal reflective benefit can be accomplished by painting OSB or plywood exteriors with aluminum paint -- compared to say the benefit derived from the foil-paper thin sheet of aluminum on the foam boards commonly used on Burn hexayurts? Would an aluminum-painted exterior halt more radiant heat intrusion than say just a white-painted exterior? I've read labels on various aluminum paints and notice that some contain no aluminum at all and others, some aluminum. So if the amount of aluminum content is the radiant barrier factor -- and not just the reflectivity -- then I can see that aluminum paint is not going to be a very effective thermal barrier. Anyone know? Is it the aluminum material that creates the radiant barrier effect or is it the reflectivity that does the trick? Or a combination of both? I do recall that Vinay pointed us a few years back to some high-tech thermal shield paints that are available. If I recall correctly, I think they were heavily impregnated with nano-sized silica crystals. When I researched locally for them, I found they would be special order items and were priced prohibitively high -- in the $60 to $80 per gallon range -- and they didn't go far. Didn't cover nearly as many square feet per gallon as traditional paints. Aluminum paints are half that price -- and would be worth it if they convey significant radiant barrier benefits, as well as serving as an exterior sealant on wood skinned hexayurts. (Would need to prime the surface with a compantible cheap sealant paint before spraying, brushing or rolling on the aluminum coat. So, lot of work, but this is for a permanent building.) Best, ken winston caine ----- Original Message ----- From: Cody Firestone To: [email protected] Sent: Tuesday, June 28, 2011 8:15 AM Subject: Re: [hexayurt] Construction details for Thermax HD On Mon, Jun 27, 2011 at 9:18 AM, R. Rochte <[email protected]> wrote: I have finally found a local supplier who carries Thermax HD (my building site is in the upper peninsula of Michigan). He stocks the 2" thickness and can order other sizes as needed. I have a few questions for those with experience - please feel free to reply in detail here or just point me to the appropriate URL if you have one: 1. Is there an "ideal" thickness of Thermax HD to use? I will have significant snow loads to deal with in the winter and the more insulation I can get, the better. But the 2" boards are already $53 each and sound like they will be more than a handful to manipulate on site. 2. Given the inevitability of LOTS of snow, should I necessarily use the Pentayurt design? Or will the greater rigidity of Thermax HD allow me to use a regular Hexayurt? 3. Are there more weatherproof seam-sealing solutions than using tape or will the tape withstand repeat exposure to cold and wet? If the tape won't withstand such exposure, how have others protected it from the elements? 4. I happen to have a concrete slab already in place where I plan to build this... Any suggestions on anchoring? I have a friend who is well-versed in conventional building techniques, so I know that he can help me drill the slab and put in anchors - just tie to these instead of using stakes, etc.? 5. Has anyone experimented with combining the increased strength of OSB with Thermax HD? That is, still using the Thermax in a structural role rather than only as insulation? You may want to consider using 3/8 plywood. OSB is less water resistant and would begin to buckle / warp. The 3/8 inch plywood, although it seems flimsy, when used in a Stress Skin Panel it adds considerable rigidity and strength. A Stress Skin panel is basically taking the foam and plywood and bonding them together with construction adhesive. Since there are MANY kinds of construction adhesive, I'd check with the manufacturers recommendation so you don't "melt" you insul board with the glue. You may also consider roofing tin on top of the angles sections to encourage sliperiness. You would need a "snow catcher" over the door area so it does not fall into the front of the door. I could see the top panels in the following way: Thin flat roofing tin on the outside, insul board in middle, 3/8 inch plywood on inside. If you wanted CRAZY strength, you could add a "Spline" which is a fitted into the ends of the panel. they would allow them to be bolted together for greater strength, and then easylit disassembled/ tape would still be used exteriorly for sealing up the hexayurt, but you could use metal / Alumninum duct tape. I'll try to do some CAD drawings of what i am talking about later today. Sincerely Yours Cody.... I don't have a degree, but i'm "Rather Clever" :-) If these questions seem trivial, please realize that I have many ideas of my own about each one but I would prefer - whenever possible - to hear the advice and learn of the experiences of those who have gone before me. I haven't found detailed answers to any of these on the web, but if you have a URL that I haven't found you are more than welcome to send it to me along with the standard, "RTFM!". Thanks! Regards, Robert -- You received this message because you are subscribed to the Google Groups "hexayurt" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/hexayurt?hl=en. -- You received this message because you are subscribed to the Google Groups "hexayurt" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/hexayurt?hl=en. -- You received this message because you are subscribed to the Google Groups "hexayurt" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/hexayurt?hl=en.
