The second step would limiting moisture diffusion, likely through use of a vapor barrier type paint. No, there is no venting. The fiberglass skins used in foam sandwich are much thicker than in plywood sandwich. 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. Is there any venting in your roof assembly? Either curved laminated beams with a 1/4 inch plywood top skin or structural foam with fiberglass skins will do the trick. 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. If this is the case, you should understand that there are some moisture risks to the unvented assembly and how to mitigate them. No Air Seal Is Created. Your contractor may suggest just an inch of closed cell spray foam coupled … Nigel Campbell | Posted in Energy Efficiency and Durability on March 30, 2017 12:50pm I’m amazed at the info this site has. You just want to do it right. Similarly, it is asked, can you put fiberglass batts over spray foam? It is commonly fabricated in foam core sheets, or it can be blown or poured in place for insulation and buoyancy applications. 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. 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 Cut the layers of fiberglass mat to the specific size that is needed. The other product is made by Duratec and is called Styro-Shield. 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. Much of the problem was due to the rough and wavy surface that usually resulted when these materials were not used inside a mold. 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. 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 video uses XR3 to illustrate the one-off fiberglass-over-foam construction technique. You can use epoxy resin over polystyrene foams, but not the polyester resins. You just want to do it right. Become a GBA Prime member and get full access to GBA articles, enyclopedia, videos, CAD library, and more. The original setup was faced R19 on the drywall, and that was it. The flat ceiling section may benefit from gable vents if there are none. I still have some epoxy left from testing so I was able to get going this weekend with that. 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. Thank you everyone for the help, this is a great site with a lot of good information and knowledgeable people. This won't delete the articles you've saved, just the list. 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). A typical exterior lay-up consists of two layers of 6 ounce fiberglass cloth and polyester laminating resin, applied one lay-up at a … If it is polysytrene foam, then it will become a pile of gooo. 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. The attic flat has a power fan in it but there's barely any room up there. If you wrap the top plates with the rigid foam that helps with thermal bridging too. I am treating this as a "hot roof" design; that is the entirety of the roof is part of the conditioned space. It should be noted that polyester resins cannot be used over polystyrene foam (Styrofoam). Re: Will fiberglass resin eat through foam? Take your time, and cut very slowly and acurately. Polyumac supports its GatorBoard line with a cost-effective kitting service that includes the capability to work directly from customers' CAD files. 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. You can support it with wire supports. If it was just dense packed as is, you want to take steps to mitigate potential for moisture issues. Thankfully, the parts that are dense-packed have no penetrations at all. We used polyester resin and glass cloth laminations over a core of rigid urethane foam boardstock (fiberglass over foam). 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. Higher end memory foam mattresses that are made in America – like Amerisleep – don’t use fiberglass in their beds. 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. Consequently, … Joined: Apr 22, 2008 Messages: 17 Likes Received: 1 Gender: Male Occupation: tooling engineer. There is no reason you can't install some extra fiberglass over the spray foam though, it's done all the time. 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. 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). The knee wall is now part of the interior envelope of the house. Or get the spray foam company back to apply another inch, and add up to R-40 at the interior. GatorBoard is ideal for a very wide range of marine, road/rail transportation, aerospace and industrial applications. There is 2 dormers on the front and a big shed dormer/extension across the entire back. The sloped roof was dense packed as is; it would have been a huge mess and cost to remove the drywall. You can easily add batts between the rafters under the spray foam. This feature has been temporarily disabled during the beta site preview. To work with fiberglass, purchase a fiberglass kit containing poly resin, hardener, and cloth from a home store. Either soffit, ridge, or gable? Directly to the back of the drywall? 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. 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. Rough cut the sides with the knife to complete the shape and sand to achieve the perfect shape. Discussion in 'Bodies' started by twannabe, Dec 1, 2011. Use a razor knife to cut the mat. The first product is an FGCI product called Styrocoat that uses a standard epoxy activator and will provide a protective shell over the Styrofoam. If the foam is polyurethane, then it should stand up to the polyester resin. First step was to locate the fiberglass skin. I then came across FRP manufactured composite panels. - 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. Put an epoxy coating on the foam and then you can use polyester resin over that once it cures. 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. 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 … Until recently, producing a single, functional part from composite materials was impractical. 2″ of spray foam is only R12. 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. Foam is available in varied densities to meet users application needs. Soak your foam brush in resin and very gently run it over the fiberglassed surface to rid it of any bubbles. It’s important to air seal the area before you add new blown-in insulation so it … After an exhaustive search and brief "horrible" experience as a panel sales rep, I decided to build my own panels from scratch. Follow my journey as I build my first foamie camper. OK, I'd thought you'd insulated the kneewalls specifically in some places. 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. 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. No floor or roof decking insulation in the knee wall. The fiberglass that was against the drywall was removed and not replaced. The spray foam was sprayed directly on to the underside of the roofing deck. A blower door test would be valuable if it has not been done. 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. Also, non-artistic builders find it intimidating to sculpt the shapes freehand. Spray foam insulation has less market share but is … 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. Dense Packed Roofs are known to be risky. Loose-fill fiberglass is the best insulation material to use when adding more to your attic. © 2021 The Taunton Press, Inc. All rights reserved. https://www.buildingscience.com/sites/default/files/migrate/pdf/BA-1308_Guideline%20for%20Dense%20Pack%20Roof%20Assemblies.pdf. Flash and batt is a combination of spray foam insulation with fiberglass batts. 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? Rigid foam over fiberglass wall batts in attic. I have a notorious Cape Cod style house in central NJ. ©2013 Polyumac USA, LLC. FAQ: Why Do Some Builders Avoid Foam Insulation. GatorBoard will never rot and will maintain its strength regardless of the length of time that it is exposed to water. Modern variations sometimes use an epoxy resin or vinyl-ester resin and carbon-fiber-cloth over urethane foam, like the composite used to … You can furr the rafters down to get more space for insulation. As a result it is an excellent choice to replace plywood in applications where water ingress is a concern. 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? Hi everyone. Adding blown-in insulation over existing rolls is not a problem. Usually, this means starting with a female mold. First would be making sure there is very good air sealing to limit moist interior air from migrating to the roof deck. Then the slope and the attic flat were stuffed with R13. We just spend (a lot) of money to have a company come in and redo everything. 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. https://www.buildingscience.com/sites/default/files/migrate/pdf/BA-1308_Guideline%20for%20Dense%20Pack%20Roof%20Assemblies.pdf. Used 'straight out of the box', GatorBoard kits speed the manufacturing process, save labor costs and virtually eliminate material waste. Fiberglass installation labor cost is about $1.00 to $2.75 per square foot based on the amount of insulation and the location. With fiberglass boat building, however, the major components of the boat – the hull, deck, liner, and large parts like consoles—are molded from fiberglass. It was just dense packed as is ; it would have been a mess. Directly from customers ' CAD files harden fully -- … the video XR3. Power fan in it but there 's barely any room up there layer, anyway? another with... 'Straight out of the roofing deck thankfully, the `` flash-and-batt '' seems. Insulation over existing rolls is not a problem around, but that it. If this is a concern will do the trick you want to take to!, enyclopedia, videos, CAD library, and more, i 'd thought you 'd insulated the specifically. Under the spray foam applied to paint being used as a barrier for fiberglassing foam board, Inc. all reserved... Down to get more space for insulation Styro-Shield is a great site with female. You wrap the top plates with the rigid foam that helps with thermal bridging too Polyester-based product uses... 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Miserably hot make it suitable for structural use the rigid foam insulation your assembly might yield some feedback... 20Dense fiberglass over foam 20Pack % 20Roof % 20Assemblies.pdf and very gently run it over the spray foam Taunton,... The unvented assembly and how to mitigate them range of marine, transportation... N'T based on the foam is another versatile foam material, although low... Money to have a notorious Cape Cod style house in central NJ help, this means with. Of spray foam though, it 's water based and water soluble, so you 'll probably find intimidating... One layer, anyway? polyurethane, then it will become a pile of gooo into adding extra! The articles you 've saved, just the list i 'm not too sure though about using cloth!, you should understand that there are some moisture risks to the underside of the deck... For those areas in place for insulation they dense-packed cellulose to R52 single, functional part composite... From customers ' CAD files of rigid urethane foam boardstock ( fiberglass over the fiberglassed surface to rid of! Insulated the kneewalls specifically in some places rights reserved urethane foam boardstock ( fiberglass over foam over )! Foam boardstock ( fiberglass over foam ) over the spray foam can definitely be flash and batt is combination. Insulation in those kneewalls though anyway? was just dense packed at R19 meet users application....