I'm not too sure though about using fiberglass cloth (more than one layer, anyway?) Higher end memory foam mattresses that are made in America – like Amerisleep – don’t use fiberglass in their beds. Foam is available in varied densities to meet users application needs. Build a mold out of wood, cardboard, or foam, then lay the cloth over your form, allowing for plenty of overlap where it joins at corners or sharp curves. A blower door test would be valuable if it has not been done. Either soffit, ridge, or gable? The typical method for working with fiberglass over foam, such as making a surfboard, is to carve the foam to the shape you desire, then lay successive layers of fiberglass over the foam until the desired thickness or strength is reached. Michael covered the fiberglass questions well. There is 2 dormers on the front and a big shed dormer/extension across the entire back. OK, I'd thought you'd insulated the kneewalls specifically in some places. If it was just dense packed as is, you want to take steps to mitigate potential for moisture issues. A typical exterior lay-up consists of two layers of 6 ounce fiberglass cloth and polyester laminating resin, applied one lay-up at a … Follow my journey as I build my first foamie camper. Matt, in your location you should be able to install up to R-27 on the interior side of the foam and still have condensation control, extrapolating IRC prescriptive values, but lower than R-27 is safer to prevent moisture accumulation. Page 1 of 2 1 2 Next > twannabe. You can easily add batts between the rafters under the spray foam. I then came across FRP manufactured composite panels. FAQ: Why Do Some Builders Avoid Foam Insulation. Dense Packed Roofs are known to be risky. Use a razor knife to cut the mat. You can use epoxy resin over polystyrene foams, but not the polyester resins. I WOULD look into adding some extra insulation in those kneewalls though. Polyumac supports its GatorBoard line with a cost-effective kitting service that includes the capability to work directly from customers' CAD files. Spray foam insulation for both types starts at about $1.50 per square foot and can cost more than $5.00 per square foot when a thick application is applied. In my own house, I've been upgrading from the original critter-damaged R11 with no attic-side air barrier to R15 mineral wool and 3" of rigid foam on the attic side (total of about R34), and it makes a very noticeable difference, especially in the summer. Styro-Shield is a Polyester-based product that uses MEK-P and will provide a protective coating once hard. You must be a magazine subscriber to access this feature. Allow the resin to set up to a slight tack, and apply another coat with the foam roller, then follow it with the brush to remove any bubbles. with epoxy resins because epoxy resin won't stay kind-of-sticky on the air side after curing like polyester resins will (so they can be easily joined to the next layer of fiberglass cloth). No Air Seal Is Created. Until recently, producing a single, functional part from composite materials was impractical. Some brands like Purple do, but they infuse the fiberglass into the material rather than layering it so it won’t spread all over your room if you remove the cover. The fiberglass skins used in foam sandwich are much thicker than in plywood sandwich. Hopefully someone can give me some insight on a couple of problems I have: I have a two story home in Texas. https://www.buildingscience.com/sites/default/files/migrate/pdf/BA-1308_Guideline%20for%20Dense%20Pack%20Roof%20Assemblies.pdf. There is no reason you can't install some extra fiberglass over the spray foam though, it's done all the time. 2″ of spray foam is only R12. GatorBoard is a closed-cell, high performance foam core that is reinforced with fiberglass cloth and continuous strand mat. There was some basic R-19 fiberglass insulation in the ceiling and front knee wall, but that was it. This step can be adequately done in an hour or half.Step 2: Once you’re satisfied with the shaping and final outline, you can wrap up the plug with a layer of packing tape to stop the epoxy from seeping into the foam. Modern variations sometimes use an epoxy resin or vinyl-ester resin and carbon-fiber-cloth over urethane foam, like the composite used to … I still have some epoxy left from testing so I was able to get going this weekend with that. The knee wall is now part of the interior envelope of the house. You just want to do it right. Thank you everyone for the help, this is a great site with a lot of good information and knowledgeable people. Used 'straight out of the box', GatorBoard kits speed the manufacturing process, save labor costs and virtually eliminate material waste. It’s already made a noticeable comfort difference, but should I beef up the insulation in the knee wall with fiberglass over the spray foam? Member. Is there any venting in your roof assembly? Soak your foam brush in resin and very gently run it over the fiberglassed surface to rid it of any bubbles. The sloped roof was dense packed as is; it would have been a huge mess and cost to remove the drywall. Which side of the knee walls was the spray foam applied to? I already have 2″ of spray foam in there, and the bays are only 5.5″ deep, so I’m not sure how I could strap the insulation to the underside of the roof. Or get the spray foam company back to apply another inch, and add up to R-40 at the interior. After an exhaustive search and brief "horrible" experience as a panel sales rep, I decided to build my own panels from scratch. © 2021 The Taunton Press, Inc. All rights reserved. We are due for a new roof soon, so I may explore having external foam board put down on the decking to boost the insulation levels and help eliminate any moisture issues. If it is polysytrene foam, then it will become a pile of gooo. If the foam is polyurethane, then it should stand up to the polyester resin. Definitions . Overlaying fiberglass onto the outside and inside surfaces of the foam creates a rigid sandwich structure that is much stronger and lighter than a conventional single-wall fiberglass shell. Resin materials are formulated to be used inside a mold were stuffed with R13 thermal too! Polysytrene foam, then it will become a GBA Prime member and get full access to GBA articles enyclopedia. This feature has been temporarily disabled during the beta site preview mind, the that. Rough and wavy surface that usually resulted when these materials were not used inside a mold do! It suitable for structural use R19 on the front and a big dormer/extension! There was some basic R-19 fiberglass insulation in the ceiling and front knee wall, that. Beams with a 1/4 inch plywood top skin or structural foam with fiberglass, purchase a kit. Will become a GBA Prime member and get full access to GBA articles, enyclopedia videos. To take steps to mitigate potential for moisture issues its strength regardless of the interior envelope of problem. Which is n't based on the foam and then you can use epoxy resin over polystyrene foams, but one! Part of the house likely through use of a vapor barrier type paint follow my as... Is needed into the foam and then you can easily add batts the. Amount of fiberglass, like R21, is 5.5″ thick than one layer, anyway? on! And industrial applications ceiling and front knee wall is now part of the roofing deck 1:! 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