The products mentioned on this page are for the sake of your information. Granby does not sell any of the noted materials or the straw bale system. However the Granby frame can readily be used with the Straw Bale infill System.
Strawbale Infill YES or NO
Straw bale infill building is an environmentally innovative system, consisting of a Post and Beam Frame structure filled in with straw bale wall panels. This building style is designed for people wishing to utilize more natural materials when building. Building from straw is an ancient technique recently rediscovered by environmentalists. The bales are relatively inexpensive and very thermally insulating. There are few other uses for straw, since, unlike hay, it can not be eaten by animals. Furthermore, because it decomposes very slowly, it isn't often used for composting. Every year thousands of tons of straw are thrown away or burned. The same things that make straw hard to use for other purposes make it ideal for building. When kept dry, straw is very sturdy. Straw has been found, completely intact, in ancient Egyptian tombs. Properly taken care of, a straw house could conceivably last equally as long. The biggest enemy of a straw house is moisture, the walls have to be completely sealed to avoid moisture problems which could cause premature deterioration of the straw. Because the straw is packed so tightly together, oxygen can not get to the middle of the bales, and so they do not burn easily. Under enough heat, they of course, will burn, but no more easily than a comparable house built of wood. Some feel that it is far superior to traditional building methods (environmentally speaking). Straw has an insulation value of R40, which means that it will take very little energy to heat or cool the house. Although the roof is the point of the majority of the heat loss in a home, so in the case of straw bale infill, in order to reap the benefit of R-40 in the walls the roof insulation would need to be superior to that amount. Since there are few straw bale houses in areas with cold wet winters, the information on the longevity of this building style is scattered and unreliable. In summary We do not recommend or discourage straw bale infill systems. For those who feel strongly, such systems are generally worth the added Engineering and difficulty. But for most the lack of a tried and true building system is enough to discourage their interest in straw bales. The use of straw bales as wall panels will actually not reduce the amount of wood in the frame of the structure. The ecological advantage of the combination of post and beam construction and straw bale construction would be that the Post and Beam Frame is recyclable as well as that the combination of two systems with excellent longevity characteristics will mean the home stays in service many generations. We hope that this information has been helpful in choosing your building style please contact Granby if you require custom pricing on your post and beam frame for your Straw Bale Infill Wall System.
Alternate Roofing Materials
These days code officials, insurance companies and homeowners are pressuring builders to find alternatives to conventional roofing products. In fire prone areas, new codes prohibit wood roofing; in many cases even fire retardant treated wood shakes and shingles are illegal. In regions susceptible to earthquakes, high wind, and hail, insurance companies are pushing builders to use roofing with better survivability. Finally, homeowners’ associations are creating covenants that require alternatives to asphalt roofing, and individual owners are asking for roofing materials that are environmentally sensitive and have longer life expectancy. Fortunately, manufacturers offer several alternative roofing materials that meet these demands, although each product must be evaluated in the context of the region and environment in which it is being applied. For instance, some materials will stand up to intense heat and UV radiation, but will fail when subjected to extreme freeze & thaw cycles. These alternative roofing systems fall into three major categories:
The list of products included here is not comprehensive, but represents the variety of materials available. Durability and fire resistance make plastic, metal, and fiber-cement good choices for residential roofs. Most plastic shakes and shingles are made from waste wood and recycled plastic from a variety of sources. Unlike wood, most plastic roofing installations can achieve a Class A fire rating, and are warranted for as long as 50 years against decay and mold or fungus growth. Formulations vary, but most products meet code requirements for temperature cycling, and resistance to freeze and thaw damage, wind uplift and degradation from UV radiation. While some products must be applied by certified installers, most can be cut and fastened just like real wood. Material costs vary from $175 to about $350 per square, and installation costs are about the same as for wood shakes or shingles.
Imitation Shakes :
I would like to thank Mid Continent Specialists for pointing out another new brand of plastic composite shake called - Virtual Shake - if you want more information on this or many other forms of roofing you can see it at their website at -
M.C.S. Roofing Virtual Shakes (tm) are made from recycled post consumer plastics and cellulose fibers. Virtual Shakes are in random widths of 6",8", and10". They can be applied over spaced strapping (1"x4") or solid plywood decking. Virtual Shakes apply exactly like cedar shakes with no noteworthy differences. They are available in 4 color choices from weathered gray to black. These shakes are class C fire rated (residential rating) and hail resistant. With an average butt thickness of 7/16" they make a very rich looking rustic roof. Virtual Shakes were designed by roofers in cooperation with plastics chemist to make the best roof and application available. The cost of Virtual Shakes on an applied basis are approx. 25% more than 1/2" cedar shakes, or about the same as a 3/4" cedar shake.
The wood and plastic composite shingles called Eco-Shakes are made from recycled pallet wood and leftover plastic from vinyl hoses, shower curtains, and bottle manufacturers. Eco-shakes come in 22 inch lengths and random widths of 5, 7, and 12 inches; premolded ridge caps are also available. The four available colors are solid throughout their thickness, so they look like conventional shakes. And like wood shakes, you can score them with a straight blade, snap them to size, and fasten them with nails or staples. Installation follows standard practice, except for an added step at the eaves, where side tabs on the undercourse shingles (made by cutting full-length shingles in half) are glued using RT-600 construction adhesive provided by the manufacturer. Each shingle in the starter course is also glued to the undercourse. Eco-Shakes must be applied to a solid deck so ply-wood may be an additional material as well as labor cost when the product is used to replace an existing shingle or shake roof on strapping.
If you want the look of slate without the weight, Authentic Roof plastic slates may be the answer. The wedge shaped solid plastic slates are 1 /4 inch thick at the butt, 12 inches wide, and 18 inches long, and can be installed at an exposure of 6 to 7 inches (special hip and ridge pieces are also available). The "shaled" edge, which is patterned after actual slate, makes the plastic roofing look like real stone. Made from 100% post industrial waste, the slates weigh about the same as standard 20 year asphalt shingles. Like wood shingles, you can score the plastic slates with a knife and snap them to size. The manufacturer is said to be working to improve the Class C fire rating; at present, however, Authentic Roof slates aren’t suitable for areas where fire is a big concern.
Another plastic roofing alternative is Perfect Choice, which is made from Noryl, a well tested industrial material manufactured by GE Plastics. Each 21 inch wide by 40 inch long thermoformed panel is molded to look like a partial course of 13 individual hand split shakes. The material can be cut with a circular saw using a diamond blade or by reversing a plywood paneling blade. Each panel is attached along the top edge with five nails, and interlocks along the sides with adjacent panels. Noryl trim pieces are also available, including caps, valleys, and hip starters. When installed over 30-pound felt underlayment, Perfect Choice has a Class C fire rating; with the addition of a 90 pound sheet membrane over the felt, the system achieves a Class A fire rating. Installed only by company-certified installers.
Cementitious Roofing-Fiber/cement roofing shingles:
These are made from Portland cement reinforced with cellulose fiber and molded to look like wood shingles, slate, and various tile shapes. Wood fibers have replaced the asbestos used to reinforce early fiber/cement materials, making today’s products more environmentally acceptable. Because air cured fiber/cement products are more vulnerable to freeze/thaw damage, some manufacturers use a steam-curing autoclave process, which increases strength and density while greatly reducing moisture absorption. Autoclaved roof tiles are a good choice for roofs in cold country, but the tiles are also more brittle than the air cured variety and are more likely to break from seismic stresses or when walked on. Many manufacturers recommend air nailing or stapling to avoid breakage from errant hammer blows. The strong suit of fiber/cement roofing tiles is their resistance to weathering, insects, fungus, and fire. Heavier tiles resist wind uplift to varying degrees; lighter tiles often need a hold-down clip to protect against uplift, although such clips can reduce breakage of any tile during earthquakes. Expect installed cost to range from $350 to $650. Warranties vary from 25 to 60 years.
For clients who want the durability of cement but the look of wood, consider Hardishakes. Although freeze-thaw concerns make these roofing tiles more suitable for warm climates, the cement content ensures a Class A fire rating (depending on the underlayment used). The 1 /4-inch-thick shakes come in 22-inch lengths and 6, 8, and 12 inch widths, and weigh about 400 pounds per square when installed
with a 10-inch exposure. Hardishakes are flexible enough to be walked on without breakage and don’t need to be predrilled or punched. They can be scored with a carbide-tipped scoring tool and snapped, and can be nailed with a pneumatic nailer. Field tiles, starter sheets, and ridge caps are available in four colors and one color blend. A fiber/cement imitation slate tile called Hardislate is also available. The composite shakes are designed to be applied with a 10-inch exposure and weigh 580 pounds per square. Installation is similar to that for wood shakes, including an interlayer of felt paper between courses. Nature Guard shakes can be nailed or stapled to solid sheathing or strapping, or applied over existing roofing. The shakes, as well as preformed hip and ridge caps, are available in four colors.
Another high end fiber/cement shingle called Eternity Slates comes in two sizes: 12x24-inch English Slate, and 11x16-inch Continental Slate. The copper storm anchor required to protect against high wind uplift is also said to inhibit moss growth. The non autoclaved tiles are flexible enough to be scored and snapped, but are said to be strong enough to resist breakage from foot traffic. The slates are prepunched for nails, and the color is consistent through the core, so there’s no need to touch up cut edges. Depending on size and exposure, the slates weigh between 384 and 467 pounds per square.
Cembrit B7, a fiber-cement roofing panel, provides the look of traditional barrel tiles, but installation requires handling and fastening many fewer individual pieces. New to the North American Market Cembrit tiles have proved themselves in Denmark (where they are manufactured) and other European countries. The pigmented layer of the 24x43-inch panels is sprayed on and compressed into the tile while the cement is still wet. After curing, an acrylic based surface coat is added to provide extra protection against weathering. Cembrit panels are prepunched to accept mounting nails or clips; corner miters required for drainage where tiles
meet are also made at the factory. The corrugated panel roofing system comes with all necessary fasteners and accessories, including angled or conical hip, ridge, and rake tiles; eaves, valley, and top closures; low slope sealant; field-and ridge vent tiles; and snow guards. At 350 pounds per square, the panels can be used in new construction or laid over existing asphalt shingles and still not exceed the average weight loading.
Freeze/thaw resistance is a given with metal, but expansion and contraction, electrolysis, and color fast coatings, as well as hail damage and noise, are all issues to consider when deciding to use metal roofing. Metal roofing is an especially attractive alternative because of its light weight, its fire resistance, and its ability in some cases to increase the shear value of the roof system. Most metal roof panels can be installed over existing roofing without any modification to the structure; some installations require the use of battens or sleepers. A variety of weather and fade resistant coatings are available, and most companies back their products with a 50-year warranty. Installed cost ranges from $350 to $500 per square.
A steel panel called California Classic comes in 14-inch by 4' steel strips that lay up like asphalt roofing. This roofing system can be applied right over existing shingle or shake roofs, or onto a plywood substrate. In a typical reroof, 1x4s securely nailed along the length of the rafters are crisscrossed with horizontal 2x2s, with 1 1 /2-inch foam insulation laid in the vertical bays. The steel panels are fastened through a raised rib with black phosphate nails. The upshot is an attractive, fire-proof roof with an added R-10 insulation value; moreover, the sleepers and interlocking steel panels turn the entire roof into a shear panel. According to the manufacturer, 16 of 17 buildings reroofed with California Classic panels in a Northridge, Calif., housing tract survived the disastrous quake intact, while dozens of surrounding houses reroofed with clay tile collapsed. The panels can be cut with tin snips or with a guillotine, and can be formed in a brake for custom flashing. The stone coating is made of ceramic granules in ten standard colors (custom color blends are also available). The company will also apply the stone coating to other roof components, including jacks, code caps over furnaces, tee tops, eyebrow
vents, chimneys, flashing, and even the fascia. Wind-Resistant Panels.
Custom full-length Panels:
The vinyl-coated hot-dipped galvanized panels in the Steel Tile Roofing System are installed vertically from eaves to ridge. The panels are 41 1 /4 inches wide in custom lengths of up to 40 feet. The roofing system weighs just one pound per foot, and can be applied over existing roofing or directly over strapping without sheathing. In addition to three industrial profiles, the roofing panels are manufactured in a Slate/Shake profile, and in two styles (Katech and Katech Elite) that resemble clay tiles. Three coating types are available in up to ten colors, as well as in aluminum and copper, and all necessary trim, flashing, and seals are included. Aluminum Shakes - The recycled aluminum alloy used to manufacture Rustic Shingles provides the ultimate in corrosion resistance.
Designed to look like wood shakes, the 12x24-inch interlocking panels come in eight colors and can be installed directly over existing roofing without the need for battens or sleepers. The nail-clip fastening system, which allows for expansion and contraction, is available in an extra-long version that can be used to attach Rustic Shingles directly to strapping or sheathing underlying a thick layer of wood shakes. According to the manufacturer, the lightweight panels are durable enough to resist hail damage and to be walked on during installation.
Eaves To Ridge Panels:
Another vertically applied panel called Met-Tile comes in 3 foot widths in lengths from 2 to 20 feet. The coated-steel panels are formed to look like Spanish tile and come with screws, closures, and all necessary accessories. Met-Tile can be installed over solid sheathing or over open steel or wood rafters. A Class A rating is possible in new construction, depending on the underlayment.
Diamond Pattern :
A diamond shaped flat metal tile called Castletop features an expanded polystyrene backing that adds insulation value and is said to protect the tile from foot traffic during installation. The 16x16-inch tiles interlace by means of a locking tab and are pre punched to accept mounting screws; interlocking upturned and downturned edges provide additional weather protection. Suitable for installation directly over existing roofing, the tiles are available in four versions: coated aluminum or steel, and natural finish copper or zinc. Trim pieces for valleys, ridges, gables, and eaves can be factory formed to spec, and coil stock is available for custom flashing in the field. The End