Rough cut the sides with the knife to complete the shape and sand to achieve the perfect shape. The sloped roof was dense packed as is; it would have been a huge mess and cost to remove the drywall. I have a notorious Cape Cod style house in central NJ. Higher end memory foam mattresses that are made in America – like Amerisleep – don’t use fiberglass in their beds. Rigid foam insulation uses one of three materials: high-quality, green-friendly polyisocyanurate; extruded polystyrene; or expanded polystyrene. Expand Collapse. https://www.youtube.com/playlist?list=PLuMPs5qUmnoTlBkwedPTYQXe98uv4rsCT If you enjoy … For the slopes they dense-packed cellulose to R19, and for the attic flat they did cellulose to R52. Put an epoxy coating on the foam and then you can use polyester resin over that once it cures. No, there is no venting. You can use epoxy resin over polystyrene foams, but not the polyester resins. Poor Mans Fiberglass, Permanent Exterior Paint, Never Paint Again (almost), Waterproofing With Out Epoxy, Fiberglass Epoxy Allergy Relief: Back in 2011 I built a teardrop camper, at the time I needed … Polyurethane foam is another versatile foam material, although its low shear point does not make it suitable for structural use. The house does get very dry in the wintertime, and we also had the bathroom fan properly vented through the roof instead of in to the attic, so I think humidity levels shouldn't be a problem. 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. This feature has been temporarily disabled during the beta site preview. In the Lost Foam technique, the foam is the mold and you dissolve the foam (or just part of the foam to keep more rigidity) when the piece is done to leave you with the resulting part. Step 1: Carve out a big chunk of the foam to match with the fuselage, and then cut out the sides using a carpet or kitchen knife. The original setup was faced R19 on the drywall, and that was it. You just want to do it right. First step was to locate the fiberglass skin. Mineral wool is less susceptible to this issue since it's denser, although you can get denser fiberglass too -- it's just not always stocked. I will put down a vapor barrier paint when repaint the drywall. 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. Then the slope and the attic flat were stuffed with R13. Ive heard about Latex paint being used as a barrier for fiberglassing foam board. GatorBoard is a closed-cell, high performance foam core that is reinforced with fiberglass cloth and continuous strand mat. Michael covered the fiberglass questions well. Either soffit, ridge, or gable? The fiberglass skins used in foam sandwich are much thicker than in plywood sandwich. Fiberglass installation labor cost is about $1.00 to $2.75 per square foot based on the amount of insulation and the location. Styro-Shield is a Polyester-based product that uses MEK-P and will provide a protective coating once hard. Don't worry too much about fraying the edge but just try to create a clean … There was some basic R-19 fiberglass insulation in the ceiling and front knee wall, but that was it. If the foam is polyurethane, then it should stand up to the polyester resin. Flash and batt is a combination of spray foam insulation with fiberglass batts. Consequently, … I WOULD look into adding some extra insulation in those kneewalls though. I still have some epoxy left from testing so I was able to get going this weekend with that. Spray foam insulation has less market share but is … You can furr the rafters down to get more space for insulation. 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. The HVAC ducts and ceiling electrical boxes/lights are all in the upper flat, and anywhere else where there is an electrical outlet, window, etc has been spray foamed. A major difference is the lamination schedule. You can easily add batts between the rafters under the spray foam. If it was just dense packed as is, you want to take steps to mitigate potential for moisture issues. You just want to do it right. The video uses XR3 to illustrate the one-off fiberglass-over-foam construction technique. 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. Can you put blown insulation over rolls? Fiberglass insulation and spray foam around windows. Rigid foam: These are panels of rigid foam, sold in 4-by-8-foot sheets in a variety of thicknesses from 1/4 to 2 inches.It is also sold in large bundled panels, joined at the ends accordion-style for use as an exterior sheathing material. OK, I'd thought you'd insulated the kneewalls specifically in some places. GatorBoard will never rot and will maintain its strength regardless of the length of time that it is exposed to water. Your contractor may suggest just an inch of closed cell spray foam coupled … A blower door test would be valuable if it has not been done. Take your time, and cut very slowly and acurately. This won't delete the articles you've saved, just the list. Or get the spray foam company back to apply another inch, and add up to R-40 at the interior. There is no reason you can't install some extra fiberglass over the spray foam though, it's done all the time. Much of the problem was due to the rough and wavy surface that usually resulted when these materials were not used inside a mold. Modern variations sometimes use an epoxy resin or vinyl-ester resin and carbon-fiber-cloth over urethane foam, like the composite used to … 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. The plan was originally to get a guy up there so put blown-in in each rafter bay, but there wasn't enough room and they had to drill drywall plugs in each bay. Nigel Campbell | Posted in Energy Efficiency and Durability on March 30, 2017 12:50pm I’m amazed at the info this site has. Directly to the back of the drywall? If the attic area is still vented it doesn't matter as much, but fiberglass really needs an air barrier to perform well so you don't want to install it on the back of the spray foam if that would leave the back of the fiberglass open to the air. To work with fiberglass, purchase a fiberglass kit containing poly resin, hardener, and cloth from a home store. Used 'straight out of the box', GatorBoard kits speed the manufacturing process, save labor costs and virtually eliminate material waste. Another post with details on your assembly might yield some useful feedback from others. Dense Packed Roofs are known to be risky. Fiberglass over spray foam? Mineral wool is less susceptible to this issue since it's denser, although you can get denser fiberglass too -- it's just not always stocked. Hi everyone. Although the video is specifically oriented to the XR3, in reality, it is goldmine of information on how to build virtually any shape or structure of foam and fiberglass, including car bodies, hovercraft, and boats. Basically drape out the fiberglass cloth over the foam board and trim the shape leaving about a 1 inch of space around the edge of the cloth. 2″ of spray foam is only R12. ps; If you really want ultralight and stiff, wander over to Boeing surplus and check out the bins of honeycomb skinned with carbon or kevlar—-. You can support it with wire supports. The roof does not have any overhang so there are no soffits, and the back that has the shed dormer is essentially a flat roof. The spray foam was sprayed directly on to the underside of the roofing deck. Page 1 of 2 1 2 Next > twannabe. It sounds like at least part of the roof is unvented dense packed at R19. I am treating this as a "hot roof" design; that is the entirety of the roof is part of the conditioned space. Allow the fiberglass to harden fully -- … https://www.buildingscience.com/sites/default/files/migrate/pdf/BA-1308_Guideline%20for%20Dense%20Pack%20Roof%20Assemblies.pdf. Also, non-artistic builders find it intimidating to sculpt the shapes freehand. Adding blown-in insulation over existing rolls is not a problem. Finally, many resin materials are formulated to be used inside a mold and do not work properly when exposed to air. The only problem is any substantial amount of fiberglass, like R21, is 5.5″ thick. You can compress fiberglass quite a bit and it will still insulate, just not quite at the rated value. The knee wall does not go all the way across the front of the house because of the dormers, so no gable vents either (and none in the attic). If this is the case, you should understand that there are some moisture risks to the unvented assembly and how to mitigate them. First would be making sure there is very good air sealing to limit moist interior air from migrating to the roof deck. I then came across FRP manufactured composite panels. After an exhaustive search and brief "horrible" experience as a panel sales rep, I decided to build my own panels from scratch. We used polyester resin and glass cloth laminations over a core of rigid urethane foam boardstock (fiberglass over foam). GatorBoard will never rot and will maintain its strength regardless of the length of time that it is exposed to water. Discussion in 'Bodies' started by twannabe, Dec 1, 2011. I'm not too sure though about using fiberglass cloth (more than one layer, anyway?) Definitions . 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. Member. This idea came to me from another build involving carbon fiber laminated over foam board. It is commonly fabricated in foam core sheets, or it can be blown or poured in place for insulation and buoyancy applications. There are a lot of articles around, but this one is pretty comprehensive. The other product is made by Duratec and is called Styro-Shield. Rigid foam over fiberglass wall batts in attic. 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. 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? 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. The knee wall is now part of the interior envelope of the house. - 1060 E. 30 St. Hialeah, FL 33013 - Tel (305) 691 9093 - Fax (305) 691 9094, Website Design by Zgraph, Inc. Florida Web Design, High 'in service' temperature performance, Compatible with most resins (polyester, epoxy and vinylester systems), Leisure & Commercial Marine - transoms, stringers & screw-retention areas, Road - bus & recreational vehicle (RV) floors. A typical exterior lay-up consists of two layers of 6 ounce fiberglass cloth and polyester laminating resin, applied one lay-up at a … It's basically a water based casting/laminating resin which isn't based on polyester resin. Fiberglass insulation is significantly cheaper than spray foam insulation, but it is also less effective, especially in extremely cold conditions.Used in roughly 85% of American homes, fiberglass insulation is the most common form of home insulation. Thanks, that is a great article. The mold is first sprayed with gelcoat, then fiberglass cloth is applied, and then resin is used to saturate or “wet out” the fiberglass. Usually, this means starting with a female mold. Affordable Insulation: Fiberglass. 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. Over the weekend I ripped a sheet of plywood into 2" strips to use in my core build, cut the bulk floor foam pieces and started putting them together. Which side of the knee walls was the spray foam applied to? The first product is an FGCI product called Styrocoat that uses a standard epoxy activator and will provide a protective shell over the Styrofoam. Similarly, it is asked, can you put fiberglass batts over spray foam? GatorBoard is ideal for a very wide range of marine, road/rail transportation, aerospace and industrial applications. Fiberglass, cellulose, and foam dominate the conversation, but the breadth of insulation products is wide, including cotton, straw, hemp, and sheep’s wool, just to name a few. Follow my journey as I build my first foamie camper. If you wrap the top plates with the rigid foam that helps with thermal bridging too. FAQ: Why Do Some Builders Avoid Foam Insulation. 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). There is no reason you can't install some extra fiberglass over the spray foam though, it's done all the time. There is 2 dormers on the front and a big shed dormer/extension across the entire back. We just spend (a lot) of money to have a company come in and redo everything. Loose-fill fiberglass is the best insulation material to use when adding more to your attic. It should be noted that polyester resins cannot be used over polystyrene foam (Styrofoam). At best they could have only a few inches of spray foam in that spot anyways since it's so close to the roof deck. Polyumac supports its GatorBoard line with a cost-effective kitting service that includes the capability to work directly from customers' CAD files. In short, you carve the shape you want in foam, cover the foam shape with layers of fiberglass and epoxy, and then get rid of the foam. The attic flat has a power fan in it but there's barely any room up there. ©2013 Polyumac USA, LLC. With fiberglass boat building, however, the major components of the boat – the hull, deck, liner, and large parts like consoles—are molded from fiberglass. Cut the layers of fiberglass mat to the specific size that is needed. Thankfully, the parts that are dense-packed have no penetrations at all. It is also an economical alternative to other cores used in the production of sandwich composite structures as it offers excellent strength and dimensional stability at elevated temperatures. No Air Seal Is Created. You must be a magazine subscriber to access this feature. 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. Hopefully someone can give me some insight on a couple of problems I have: I have a two story home in Texas. As a result it is an excellent choice to replace plywood in applications where water ingress is a concern. Should work well and perfectly safe for those areas. Thank you everyone for the help, this is a great site with a lot of good information and knowledgeable people. The flat ceiling section may benefit from gable vents if there are none. Last winter was miserably cold upstairs, and the summer was miserably hot. Managing such an assembly involves optimizing air sealing, establishing a vapor barrier (likely paint), and managing indoor humidity levels. The second step would limiting moisture diffusion, likely through use of a vapor barrier type paint. Foam is available in varied densities to meet users application needs. Thanks to the inability to access most of the house, they ended up doing 2″ of spray foam to the front knee walls areas, from the floor up along the roof line. Is the sloped roof above the sloped ceiling spray foamed as in you had the drywall removed and sprayed it or was it dense packed as is? Building a foam sandwich boat step by step: build a jig plank the jig with foam panels fiberglass the outside flip the hull remove jig fiberglass inside install internal structure 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. So at least in my mind, the "flash-and-batt" approach seems likes the easiest, cheapest, and best method? Re: Will fiberglass resin eat through foam? The fiberglass that was against the drywall was removed and not replaced. It’s important to air seal the area before you add new blown-in insulation so it … © 2021 The Taunton Press, Inc. All rights reserved. If it is polysytrene foam, then it will become a pile of gooo. https://www.buildingscience.com/sites/default/files/migrate/pdf/BA-1308_Guideline%20for%20Dense%20Pack%20Roof%20Assemblies.pdf. 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Articles you 've saved, just the list R21, is 5.5″ thick epoxy over..., purchase a fiberglass kit containing poly resin, hardener, and that was against drywall. Another post with details on your assembly might yield some useful feedback from others construction technique fiberglass... Envelope of the house a result it is asked, can you put fiberglass batts they dense-packed to! Articles, enyclopedia, videos, CAD library, and that was it top skin or structural foam with,! Installation labor cost is about $ 1.00 to $ 2.75 per square foot based on the of. A protective coating once hard limit moist interior air from migrating to the polyester resins not... And batt as Michael said to R52 Polyester-based product that uses MEK-P and will provide protective! There are some moisture risks to the rough and wavy surface that usually resulted these...