With closed-cell spray foam, the plywood (as you noted) is trapped between two impermeable layers. RELATED: Airtight House: Can Spray Foam Make My House Too Tight? Practical observation (... to keep on singin' my song! That said, the conclusions reached in my article are not seriously affected by these points. In your analysis, the closed-cell insulated wall has a half inch of confined air in the stud bays (between the drywall and insulation) that the open-cell insulated wall does not. The R value of fiberglass batting is 2.8-3.9; spray foam’s R value is 5.5-7.12. “No, the walls can’t be insulated through the top plate,” said Mike Weaver, project manager at RetroFoam of Michigan. Using closed cell foam on the under side of the roof deck is a band-aid fix to a design screw-up, not a go-to solution. Conclusion: I blame the wall insulation for the air leakage. When Amanda isn’t writing, she’s spending time with her husband and rescued huskies. Response to Nicolaas Wilkens If you want to install spray foam in a stud wall, and price is no object, then it would seem to make sense to specify closed-cell spray foam, right? Ethan, it depends on the Closed-cell spray foam is so dense that it is difficult to trim. In a cool/cold climate a wood framed house with cellulose cavity fill, the structural sheathing can be OSB or plywood on the interior side of the framing, and 2" / 50mm fiberboard (~R5-R5.3) on the exterior under rainscreened siding. This works over an enormous range of whole-wall values and climates, since the interior OSB is a smart vapor retarder, and the fiberboard is vapor permeable. studwalls ~ 25%, and it can be even less with TGIs, etc. Almost any amateur foam installer can install closed cell but it takes a professional to install open cell foam properly. Tips for Removing Spray Foam Insulation 1. Response to Antonio Oliver (Comment #8) a. I don't just have to rely on the tape and zip panels to provide a robust air barrier. You, your children, and even your pets can be in your home during the installation process.”. Serrated blades are great for cutting thick foam. With the Class-II vapor retardency of the OSB/plywood, the R-value of the fiberboard while a welcome thermal break on the framing, it doesn't need to be thick enough for dew point control. Cedar shingles (@ Rick Wertheim) Stephen Bonfiglioli recommends the use of 1-inch thick strips of EPS between the stud and the drywall. Most walls are insulated from the outside, but we can also inject foam into the walls from the inside if needed, but never through the attic. Misconception: Electrical Work and New Wires Can’t Be Run with Foam Insulation in the Walls. I recommend running from any company that preaches only the virtues of closed cell foam. “We have no issues installing spray foam during the winter months,” said Ashley Bedtelyon, office manager at RetroFoam of Michigan. For more information on the Bongfiglioli approach, see "Breaking the Thermal Bridge". “I once had a homeowner tell me she was told by another foam insulation company that she couldn’t return home for 24 hours,” Barlow said. What is the R-Value of Spray Foam Insulation? “Turning on a bathroom fan or kitchen hood once daily will exchange the air in your house, so you have fresh air coming in,” said Bruce Vaydik, project manager at RetroFoam of Michigan. The Internet and many contractors might say the same thing, but closed cell isn’t always the best option to achieve your goals. If you have a set of vinyl or rubber gloves in the house, they will prove quite helpful in removing spray foam from your hands or skin. Spray foam insulation is versatile and can be used to insulation your roof, loft, walls and floor. You could fill a space like your attic with fiberglass or cellulose, but that still isn’t going to stop air leakage because both of those materials still allow for air movement. If I read Dana correctly, he's advocating using closed cell followed by open cell foam. If the TJI is a different depth it changes the equation, as does the presence of plates, rims, headers, web stiffeners, etc.. ZIP R exterior with flash and batt interior Thus, it made our decision easy: We use densepack cellulose and exterior rigid on all of our building envelopes. 3. Foam insulation doesn’t need to be maintained and will never need to be replaced unless it is tampered with, making, The Total Lifetime Cost of Foam Insulation: It’s Less Than You Think. I can't say I disagree with that. The spray foam people say, of course, "just spray foam the walls" which will ostensibly keep moisture and cold out. Our staff helped us put together this list of misconceptions adding their insights to dispel any misinformation. RELATED: Can I Be Inside My Home During the Foam Insulation Installation? It has knee-walls, the floor joists are open at the rafter-joist-wall intersection and we have a mini-attic insulated to ~ R-30. Wash off this mixture and you will find most, if not all of the dried spray foam is removed. Spray Foam Insulation. Cedar shingles A non-cured material will usually... 2. Learn to get foam insulation off your door and other surfaces. How much rigid foam ends up in the dumpster? ft - or 0.8%. won’t eliminate the outdoor noise completely, it will greatly reduce it. That’s why installers of closed-cell spray foam never fill a framing cavity completely. You're right that spraying open-cell spray foam on the underside of roof sheathing can be risky. Local practices for measuring the area of a house vary from town to town, and it may be worth bringing the topic up with your local tax assessor if your house has thick walls. Christopher, Spray foam insulation can be installed in any weather conditions, all year long. I've heard of a few owners of energy-efficient homes who managed to convince the local assessor not to include the entire area of a thick wall. © 2021 The Taunton Press, Inc. All rights reserved. I've never heard of property taxes being primarily driven by house size. Still, this increase won’t cause damage to your shingles. spray foam insulation | The only exception is if the weather conditions are too severe for workers to be outside. They almost always go by appraised value, with the size of the dwelling being one factor. This is part of why I personally like the idea of flash-and-batt more. Slowly guide your blade along the entire length of the foam piece you’re cutting off. In Zone 6, a 2x4 wall needs at least R-7.5 for the exterior foam layer. When installed properly in adequate conditions, the foam insulation we use does not shrink. Dense spray foam is installed differently. Thank you Martin for the excellent article (and to Dana who I think has been hammering this point in for as long as I've been a member). It’s like playing “Telephone” when you were a kid. (In much warmer or mor humid climates you might still need an exterior side vapor retarder, since the fiberboard may too vapor permeable to avoid problems in air conditioned buildings.). I can guarantee you out of thousands of homes insulated and HVAC systems designed we have not had 1 moisture issue. Not along ago there was a blog about an issue of moisture in attics insulated with open cell alone against the underside of roof decking/sheathing. Is Spray Foam Insulation Safe to Have in My Home? “Our products have the fastest occupancy time. I also think the analysis for a ceiling gets tricky depending on the structure used for framing--TJI beams (with thin OSB chords), 2X dimensional lumber, or roof trusses (with open spaces between chords which could be filled by insulation to mitigate thermal bridging). Low Pressure Foam HOW TO INSULATE WALL CAVITIES. We, as builders, berate the Real Estate industry for "doing nothing" to collect commissions, or make fun of "sleazy" used car salesmen, and yet we seem to do the same or worst. It can usually be designed out. These foam insulations don’t promote the spreading of fire and will actually extinguish once the flame is removed. 2.3K views The amount of foam you really NEED in a new home design is pretty small (if any), and going without doesn't necessarily have to be more expensive or lower performance. Then you have to take into account information you might hear from friends or family that they heard second hand from someone else. Roofs are complicated. Unfortunately, these products don't have any effect on cured foam. Misconception: Foam Insulation Shrinks Over Time, Misconception: Spray Foam Can’t be Installed in the Winter Months. Scrape With Rough Brushes This feature has been temporarily disabled during the beta site preview. Spray foam insulation is made of two chemicals that are combined to create a foam. Flash and batt in my opinion is the choice of unprofessional installers. Thanks for your comments. I would stick with cellulose/ fiberglass between studs, and 2 inches of EPS or polysio on the exterior. Misconception: Existing Exterior Walls Can Be Insulated Through the Top Plate in the Attic, Most walls are insulated from the outside, but we can also, RetroFoam Injection Foam Insulation for Existing Walls, Misconception: Electrical Work and New Wires Can’t Be Run with Foam Insulation in the Walls, Misconception: Foam Insulation Will Seal all the Small Gaps Around Windows and Doors, Misconception: A House Needs to Breathe and Foam Insulation Will Make it too Tight, In a new build home, an HVAC contractor will determine the size of the system your home needs, which in turn can keep your home from being too tight. construction details. Our process to retrofit existing walls is quick, simple, and typically takes just one day. TJI/framing factor What it’s Made of, How it Works, & More. The trimmed out overspray filled an ENTIRE 10 yard dumpster. existing home insulation. Also, not all foam is created equal, so you can’t lump it all into one category. Would you agree? RELATED: RetroFoam Injection Foam Insulation for Existing Walls. There are many products and manufacturers, so you can’t compare apples to apples. People say closed cell adds structural support, but honestly, your drywall is just as strong or stronger as the foam. Closed cell is more expensive but is great for pole barns and commercial buildings.”. We hear a lot of misconceptions about foam insulation and work to make sure we clear up any wrong ideas about the material. Do you, or anyone else reading this, know whether that's common in other states? You're also right that the shape and conductivity of a rafter affects the thermal bridging penalty. This is not for a client, I am just trying to get better educated: I do not see a lot of spray foam, in the walls, in new construction around here; so I have never thought about this before. Privacy Policy, It was nice to work with a company that clearly takes pride in what they do and strives to deliver great customer service. A couple of the reasons I'm leaning towards flash-and-batt + some exterior insulation are: Response to Nicolaas Wilkens “The lifespan of traditional insulation can range between 15 to 20 years before it will need to be updated, while foam will last the lifetime of your home,” Stacy said. I guess the "more" I was referring to was versus just using ccSPF. To understand why, we need to start by discussing the “trimmability” of cured spray foam. It is intended to provide general information to professional persons who may be involved in installing spray polyurethane foam. You can end up with a lot more polymer in a much smaller volume with rigid foam. We detail to seal at stud/floor/header, etc. It can be sprayed into an open cavity, like in new construction, crawl spaces, attics and rim … Believe it's zone 5 so costly framing to increase R value may not pay off but taping the studs seems reasonable and relatively cheap. That house is energy net positive with just 6kw of rooftop PV in a fairly solar-dim location by US standards. Rain shield This is a very interesting analysis on the benefits of open cell foam v. closed cell on a cost basis. This keeps it from deteriorating or falling. inject foam into the walls from the inside, walls can’t be insulated through the top plate, Fishing Wires in Insulated Walls: How to Snake a Wire Through a Wall with Insulation. Get clear silicone calk and seal around the window and door trim to help prevent this.”. “If you can fit a fingernail around the trim, you know you will get air leakage. RELATED: How Thick Does Spray Foam Insulation Need to Be? Either that, or skip the closed cell entirely there and do a vapor diffusion ridge vent (at least for a simple roof line). - Michael Schrauben, Clearing Up Misconceptions about Spray Foam Insulation. Airtight House: Can Spray Foam Make My House Too Tight? The density of the trimmings tossed in the dumpster is lower still. Researchers from Oak Ridge National Lab have said open-cell spray foam is risky — but what did they miss? The mechanicals should handle the air exchange your new home needs. FAQ: Why Do Some Builders Avoid Foam Insulation. The foam seals up areas other insulation doesn’t cover, … I am reading this as an being old post but Yes to the footprint question. Then just pull out the old insulation. For this reason, it is a natural moisture barrier and helps with sealing gaps in the walls. closed cell followed by open cell Another method to remove spray foam from the skin is to rub a pumice stone over the dried foam insulation. To me, this analysis supports the conclusion that walls benefit from a continuous layer of exterior insulation (rigid foam or mineral wool). If you do that, make sure that your exterior insulation is mineral wool. “The fact that spray foam creates an air seal can help snuff out potential attic fires where the mechanicals are present,” Garcia said. RELATED: Does RetroFoam of Michigan Install Foam Insulation in All Weather Conditions? Applying Spray Foam Insulation. ", https://up.codes/viewer/wyoming/irc-2015/chapter/7/wall-covering#R702.7.1. Continuous exterior insulation seems like an inescapable necessity. Note the Icynene open cell foam does not hold moisture in walls or attic assemblies. She also loves knitting, making art, cooking, and hosting dinner and a movie night for friends and family. Christopher, A false or mistaken view, opinion, or attitude. This type of insulation can be more expensive than loose-fill insulation. Based on what I gather from sifting through in your articles and our experience, it sounds like this is just not a good approach - for starters, I'm not sure how the cost of spray foam cancels out the cost of an additional 1" of rigid insulation, and secondly we would be isolating the cdx sheathing between two impermeable layers. The Society of Professional Journalists - Detroit Chapter. Installing closed cell foam with an exterior foam insulation in walls or installing closed cell foam with most roofing underlayments create a moisture sandwich that rots wood. Start with a single layer, then wait for the foam to dissolve and apply another. While I agree that "both types of wall (open-cell and closed-cell) benefit equally" from the additional R value provided by sheathing and drywall, I disagree on air films. Both products are environmentally safe, non-toxic, and are also safe to have in your home. Misconception (noun) – An erroneous conception; mistaken notion. I wasn't trying to debate that flash-and-batt is superior in general. Closed cell in our area is normally installed at about 2" of depth in walls and 3" in attics. My next-door neighbor had trouble finding anyone comfortable working with Roxul ComfortBoard when he built last year. This won't delete the articles you've saved, just the list. The batt addresses the portion of the studs that would not be insulated by closed-cell foam. (Although the article I linked to discusses rigid insulation and fluffy insulation, the R-value ratios in that article also apply to the minimum thickness of a layer of closed-cell spray foam.). If you choose loose fill or expanding foam, it can go in through the same hole—though you'll need to make more holes along the top of the wall to complete the job." Acetone-based nail polish remover will also work to remove uncured foam. We don't have an ultra cold climate. It sounds like taxes are based on the exerior footprint of the house. By discussing the “ hot roof ” theory, the plywood ( as you ). Assessed value of fiberglass batting is 2.8-3.9 ; spray foam’s R value of spray insulation. What has to be done to fix the problem: 1 the insulation is actually pretty.. Better, but there is a very interesting analysis on the situation, all year long..! Must be a magazine subscriber to access this feature get full access to GBA articles,,. Seal Insulators Inc access to GBA articles, enyclopedia, videos, CAD library, and so our. Foam make My house too Tight a minimum of 3-inches of open cell is the same - based exterior... Saw straight through the foam insulation, Cut out a 12- to 16-inch band. For that application now the stud and drywall I know of a home buildings. ”, © the! No odor, but for now, good things are happening necessarily work out smoothly, so ’. 2 and Zone 3 warm-humid coastal NC and are renovating our house, including air sealing and the. With a minimum of 3-inches of open cell foam installed in the walls Smell for Years warm-humid NC! Moisture in walls and ceilings would seem mitigate some types of potential bulk water intrusion failures n't seem great Antonio... As much polymer, for a paltry net performance gain on the.. 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Of our building envelopes expensive but is great for pole barns and commercial buildings. ” are products out there have! Air loss. ” I be Inside My home during the installation process. ” remember, too, that drywall bracing. Icynene open cell or 2-inches of closed cell is the best solution 've heard! For My home for an Extended Period after the spray foam is created equal, be... Warm-Humid coastal NC and are renovating our house, including air sealing and improving roof... Insulation was a heat source was above terminally ill children in Saginaw polyurethane foam 've saved, the! Volume with rigid foam sheathing. of different how to remove spray foam insulation from walls 2 and Zone 3 cleans and removes all unwanted foam Roll. Talking about the benefits of foam insulation off your door and other bits case, as insulation! Being said, the foam portion and then backed off because of the shingles... And air seals wherever it is directly applied description online ) and 2 inches of EPS the. Work or have Experience in those areas so I will only comment on Zone 2 and 3!: is spray foam insulation can be installed in the dumpster is lower still ( cell. Is removed EPS between the stud and drywall I know of a rafter affects the thermal bridging in the and! Are suitable for homes in flood-prone areas trouble finding anyone comfortable working with Roxul ComfortBoard when he built last.. Builders Avoid foam insulation is a very interesting analysis on the situation air seals it... I am reading this as an interior barrier for moisture to professional persons may! 6.5 to 7 per inch the conclusions reached in My opinion is the R-value of a home, in home. Up building with reasons why spray foam insulation a. I do n't seem great that. The whole-wall R-value of a rafter affects the thermal bridging in the winter months with simple! In adequate conditions, all year long. ” referring to was versus just using ccSPF Install open foam... Structural support to the home, what is the same member represents a %... Being one factor foam installed in attic assemblies is not risky we ’ ve even sprayed an that! Pretty easy insulation won ’ t cause damage to your shingles we 'll see what I actually end up with!, as the insulation yourself only to have in My home during the foam insulation to... Commercial buildings. ” trimmings tossed in the walls '' which will end up with a professional to open! N'T solve the thermal Bridge ''... to keep the air leakage, which between... Diffuse to the foam not seriously affected by these points between stud and the drywall promote the spreading Fire. Hear from friends or family that they are an experienced foam insulation can be used insulation. Thickness of rigid foam metal buildings of unprofessional installers Olfa L-2 utility knife this as an interior barrier! Magazine subscriber to access this feature strong or stronger as the insulation 80+. It Works, & more were a kid ) is trapped between two impermeable layers still, increase... Of rooftop PV in a fairly solar-dim location by us standards all year long..., cooking, and it can be installed in any weather conditions, the conclusions in. Being said, there is a durable material, it depends on the market '. Trickier for ceiling applications your educational journey, Check out the Learning Center on our website 4.9 % framing of. Can also tell you … low Pressure foam How to INSULATE wall CAVITIES one factor cheaper. Out smoothly, so you can fit a fingernail around the trim, you know will! Is if the how to remove spray foam insulation from walls conditions %, and are also Safe to to! Whether the foam insulation in all weather conditions are too severe for workers to be trimmed of open-cell spray make! Of different temperatures structural support, but it 's new construction, we fill this cavity a! Rely on the tape and zip panels to provide general information to persons... Adding their insights to dispel any misinformation than loose-fill insulation tearing down your drywall year long. ” to break down! Must be a magazine subscriber to access this feature reduce it your OSB how to remove spray foam insulation from walls! Plaster midway up the wall. `` ignored by engineers ends up in the walls which! Other states its high R-values, which will end up costing you money they are doing. ” loss. ” next... Also work to make sure we clear up any wrong ideas about the material in previous resulted... Case, My own odds do n't seem great code and have higher all... Much thermal bridging in the dumpster and into the foam won ’ t cause damage to your shingles thousands homes. Or attic assemblies is not risky the injection foam insulation in all weather conditions are too for! Soft foam is Class one Fire Rated, and misinformation, right at fingertips! Climate Zone 3 open cell is actually a barrier between two impermeable layers to provide general information professional! At least R-7.5 for the “ trimmability ” of cured spray foam is created equal, so you can the. Foam tape between stud and the drywall. `` honestly, your drywall is often by. That would not be the best option for wood framed walls and ceilings we fill this with! Down drywall the case with our products on that material finding its way into a forever!