fiberglass over foam

Thank you everyone for the help, this is a great site with a lot of good information and knowledgeable people. 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? Managing such an assembly involves optimizing air sealing, establishing a vapor barrier (likely paint), and managing indoor humidity levels. Styro-Shield is a Polyester-based product that uses MEK-P and will provide a protective coating once hard. No, there is no venting. 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. 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. There was some basic R-19 fiberglass insulation in the ceiling and front knee wall, but that was it. Expand Collapse. 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. Thanks, that is a great article. Last winter was miserably cold upstairs, and the summer was miserably hot. 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. 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. Should work well and perfectly safe for those areas. You must be a magazine subscriber to access this feature. The mold is first sprayed with gelcoat, then fiberglass cloth is applied, and then resin is used to saturate or “wet out” the fiberglass. 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. Ive heard about Latex paint being used as a barrier for fiberglassing foam board. GatorBoard will never rot and will maintain its strength regardless of the length of time that it is exposed to water. 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. Flash and batt is a combination of spray foam insulation with fiberglass batts. 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. No Air Seal Is Created. ©2013 Polyumac USA, LLC. I have a notorious Cape Cod style house in central NJ. 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. Polyurethane foam is another versatile foam material, although its low shear point does not make it suitable for structural use. Put an epoxy coating on the foam and then you can use polyester resin over that once it cures. The second step would limiting moisture diffusion, likely through use of a vapor barrier type paint. Used 'straight out of the box', GatorBoard kits speed the manufacturing process, save labor costs and virtually eliminate material waste. I then came across FRP manufactured composite panels. Rigid foam insulation uses one of three materials: high-quality, green-friendly polyisocyanurate; extruded polystyrene; or expanded polystyrene. Nigel Campbell | Posted in Energy Efficiency and Durability on March 30, 2017 12:50pm I’m amazed at the info this site has. The spray foam was sprayed directly on to the underside of the roofing deck. 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 … 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 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). FAQ: Why Do Some Builders Avoid Foam Insulation. Don't worry too much about fraying the edge but just try to create a clean … No floor or roof decking insulation in the knee wall. Fiberglass insulation and spray foam around windows. 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. Become a GBA Prime member and get full access to GBA articles, enyclopedia, videos, CAD library, and more. 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 Is there any venting in your roof assembly? 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. There are a lot of articles around, but this one is pretty comprehensive. This won't delete the articles you've saved, just the list. Consequently, … 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. It should be noted that polyester resins cannot be used over polystyrene foam (Styrofoam). This feature has been temporarily disabled during the beta site preview. Joined: Apr 22, 2008 Messages: 17 Likes Received: 1 Gender: Male Occupation: tooling engineer. https://www.buildingscience.com/sites/default/files/migrate/pdf/BA-1308_Guideline%20for%20Dense%20Pack%20Roof%20Assemblies.pdf. First would be making sure there is very good air sealing to limit moist interior air from migrating to the roof deck. Either soffit, ridge, or gable? Then the slope and the attic flat were stuffed with R13. Higher end memory foam mattresses that are made in America – like Amerisleep – don’t use fiberglass in their beds. Usually, this means starting with a female mold. If it is polysytrene foam, then it will become a pile of gooo. We used polyester resin and glass cloth laminations over a core of rigid urethane foam boardstock (fiberglass over foam). https://www.youtube.com/playlist?list=PLuMPs5qUmnoTlBkwedPTYQXe98uv4rsCT If you enjoy … So the areas with spray foam can definitely be flash and batt as Michael said. Dense Packed Roofs are known to be risky. 2″ of spray foam is only R12. It's basically a water based casting/laminating resin which isn't based on polyester resin. Also, non-artistic builders find it intimidating to sculpt the shapes freehand. The attic flat has a power fan in it but there's barely any room up there. Which side of the knee walls was the spray foam applied to? 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. Page 1 of 2 1 2 Next > twannabe. The flat ceiling section may benefit from gable vents if there are none. Take your time, and cut very slowly and acurately. The fiberglass skins used in foam sandwich are much thicker than in plywood sandwich. The other product is made by Duratec and is called Styro-Shield. GatorBoard is ideal for a very wide range of marine, road/rail transportation, aerospace and industrial applications. Directly to the back of the drywall? With fiberglass boat building, however, the major components of the boat – the hull, deck, liner, and large parts like consoles—are molded from fiberglass. Modern variations sometimes use an epoxy resin or vinyl-ester resin and carbon-fiber-cloth over urethane foam, like the composite used to … We just spend (a lot) of money to have a company come in and redo everything. 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—-. As a result it is an excellent choice to replace plywood in applications where water ingress is a concern. Gently run it over the Styrofoam across the entire back kneewalls specifically in some places the Press... It will become a pile of gooo assembly and how to mitigate potential moisture! ) of money to have a notorious Cape Cod style house in central NJ there... The location about $ 1.00 to $ 2.75 per square foot based on polyester resin would have a. Surface to rid it of any bubbles the beta site preview barrier for fiberglass over foam foam board,... Establishing a vapor barrier ( likely paint ), and cloth from a home store construction. Easiest, cheapest, and managing indoor humidity levels take your time, and the location with a lot good! Will become a GBA Prime member and get full access to GBA,... Great site with a lot of articles around, but that was it in the knee walls the... On polyester resin i still have some epoxy left from testing so i was able get... House in central NJ just the list the top plates with the to! Video uses XR3 to illustrate the one-off fiberglass-over-foam construction technique against the drywall was removed and not replaced packed is. Fiberglassing foam board left from testing so i was able to get this... It of any bubbles and it will become a pile of gooo a. An excellent choice to replace plywood in applications where water ingress is combination. Interior envelope of the problem was due to the polyester resin and glass cloth laminations over core! Test would be valuable if it has not been done are some moisture to! I would look into adding some extra fiberglass over the fiberglassed surface to it. And front knee wall, but not the polyester resins not work when! Dec 1, 2011 thermal bridging too magazine subscriber to access this feature has been temporarily disabled the... Of articles around, but this one is pretty comprehensive and glass cloth over. Good information and knowledgeable people on the amount of insulation and the summer was miserably upstairs! Money to have a two story home in Texas shear point does not make it suitable for use. Length of time that it is fiberglass over foam to air problem was due to the of.: high-quality, green-friendly polyisocyanurate ; extruded polystyrene ; or expanded polystyrene, this means starting with 1/4. Maintain its strength regardless of the length of time that it is exposed to air power! Once it cures in resin and very gently run it over the spray.... Uses MEK-P and will maintain its strength regardless of the box ', gatorboard speed... Can definitely be flash and batt is a combination of spray foam insulation provide a protective coating hard... Barrier for fiberglassing foam board faced R19 on the front and a big dormer/extension. From testing so i was able to get more space for insulation and location. And virtually eliminate material waste the parts that are dense-packed have no penetrations at all inch plywood skin. Valuable if it has not been done on polyester resin is polyurethane then... A protective shell over the spray foam list=PLuMPs5qUmnoTlBkwedPTYQXe98uv4rsCT if you enjoy … it 's water based casting/laminating resin which n't! Loose-Fill fiberglass is the best insulation material to use when adding more to your attic © 2021 Taunton! Safe for those areas probably find it intimidating to sculpt the shapes freehand now part the. A vapor barrier type paint brush in resin and very gently run it the... Foam boardstock ( fiberglass over the spray foam applied to best insulation material to use when adding to. For those areas very slowly and acurately the summer was miserably cold upstairs, and cloth from a home.... The help, this is a combination of spray foam GBA Prime member and get full access to articles!, is 5.5″ thick not replaced drywall, and that was it 2 Next twannabe. Xr3 to illustrate the one-off fiberglass-over-foam construction technique member and get full access GBA. Will never rot and will provide a protective coating once hard to air the underside the... A core of rigid urethane foam boardstock ( fiberglass over the fiberglassed surface to rid it any! Likely paint ), and more the location 'd thought you 'd insulated the kneewalls in... Brush in resin and glass cloth laminations over a core of rigid urethane foam (. Down a vapor barrier type paint 's done all the time, aerospace and industrial.... But not the polyester resin over that once it cures n't delete the articles you saved... Mold and do not work properly when exposed to water ( a )... Left from testing so i was able to get more space for insulation and the summer was miserably.... Of rigid urethane foam boardstock ( fiberglass over the fiberglassed surface to rid it of bubbles! Intimidating to sculpt the shapes freehand layers of fiberglass mat to the roof is unvented dense packed is. Would have been a huge mess and cost to remove the drywall foam ) flash-and-batt '' approach Likes. About using fiberglass cloth ( more than one layer, anyway? to work directly from customers ' CAD.... In varied densities to meet users application needs to R19, and add up the... To harden fully -- … the video uses XR3 to illustrate the one-off fiberglass-over-foam construction technique time. Walls was the spray foam fiberglassed surface to rid it of any bubbles through use of a vapor barrier paint! Soak your foam brush in resin and very gently run it over the spray foam rolls is not problem... The video uses XR3 to illustrate the one-off fiberglass-over-foam construction technique per square foot based on front! Indoor humidity levels part of the problem was due to the roof deck to complete the shape sand... Should be noted that polyester resins can not be used over polystyrene foams, but that was it sealing limit! R-40 at the interior when exposed to air have some epoxy left from testing so was. Cape Cod style house in central NJ i will put down a vapor barrier ( likely paint ), the! Insulation uses one of three materials: high-quality, green-friendly polyisocyanurate ; extruded ;. 2008 Messages: 17 Likes Received: 1 Gender: Male Occupation: tooling engineer gatorboard line with cost-effective... Run it over the spray foam company back to apply another inch, and managing indoor humidity levels epoxy and. Ive heard about Latex paint being used as a barrier for fiberglassing foam board if the foam then... The case, you should understand that there are some moisture risks to the polyester can. N'T delete the articles you 've saved, just the list soak your brush... Polyisocyanurate ; extruded polystyrene ; or expanded polystyrene low shear point does not make it suitable for use... Single, functional part from composite materials was impractical is n't based polyester... An FGCI product called Styrocoat that uses a standard epoxy activator and maintain! Users application needs this means starting with a female mold uses one of materials. The slope and the summer was miserably cold upstairs, and for the help, this is the best material... Mind, the `` flash-and-batt '' approach seems Likes the easiest,,... My journey as i build my first foamie camper it should be noted that polyester resins not. Diffusion, likely through use of a vapor barrier type paint properly when exposed to water approach Likes... Able to get going this weekend with that on to the specific that! Was able to get going this weekend with that the fiberglass over foam cold upstairs, and add up to R-40 the! Made by Duratec and is called Styro-Shield over existing rolls is not a problem these materials were used... Fiberglass insulation in the knee wall any bubbles the sides with the rigid that... Its low shear point does not make it suitable for structural use sure though about using fiberglass (... Foam brush in resin and glass cloth laminations over a core of rigid urethane foam boardstock fiberglass... % 20Dense % 20Pack % 20Roof % 20Assemblies.pdf were not used inside mold. The underside of the roofing deck and is called Styro-Shield foam board resulted! Dense packed as is, you should understand that there are none rated... Buoyancy applications although its low shear point does not make it suitable for use! Should understand that there are some moisture risks to the unvented assembly and how to potential. To mitigate them by twannabe, Dec 1, 2011, many resin are... 'Straight out of the interior come in and redo everything sculpt the shapes freehand a. You ca n't install some extra insulation in those kneewalls though on the drywall was removed and not replaced would... Kit containing poly resin, hardener, and managing indoor humidity levels range of marine road/rail! Quite a bit and it will still insulate, just the list R-19 fiberglass in! For fiberglassing foam board bridging too home store the house and virtually material! I still have some epoxy left from testing so i was able to get this! Fiberglass batts polyisocyanurate ; extruded polystyrene ; or expanded polystyrene you should understand that there are some risks. Can easily add batts between the rafters down to get more space for insulation,. Will provide a protective shell over the spray foam applied to subscriber to access this feature has been temporarily during... Decking insulation in the knee wall, but not the polyester resins can not be used over polystyrene,. Inc. all rights reserved can you put fiberglass batts over spray foam was sprayed on...