There's tons of information out there. The reason for this is spray foam insulation can be very dangerous when on fire and in some cases can not be extinguished. Air sealing a home, in addition to maximizing R-value, will further improve energy performance. Lastly, there is nothing wrong with fiberglass if it is installed correctly. Its not difficult. Rain Control: Rain control is typically addressed using a shingle lapped and/or taped water control layer such as building paper or a synthetic WRB (i.e. Cellulose is generally considered better than foam or fiberglass for sound - it is heavy. with 5" high-density spray foam cavity insulation. All of the information and comments are truly appreciated here. Air infiltration is very important but can be addressed in a lower cost way. Closed cell, or high density foam, is a better insulator and will not take on water. There are no circumstances in which a 2x4 wall should be on the table in your location. With any of these products it pays to get someone who can install the insulation correctly ensuring no voids or gaps. Loose fill cellulose is almost R 20. Learn what exactly spray foam is, the pros and cons of using it and why you shouldn’t mess around with installation, A budget-friendly redo turns a ho-hum pool house into a beachy oasis for entertaining and hosting houseguests, Designers are embracing the once common but recently overlooked square tile in kitchens and bathrooms, Learn about the pros and cons of healthier alternatives to fiberglass and foam, and when to consider an insulation switch. Spray foam insulation kits are a great choice because they can insulate all sorts of spaces from wall cavities to floors. Springtime Builders - The assemblies they are constructing meet the full requirements of the code. The challenge is developing methods of construction that provides the appropriate performance while at the same time it does not drive up the cost to construct. After subtracting the window area, the area of exterior walls might be less than the area of the roof. There are some slow-expanding foam insulation products for existing walls, but the product can be applied easier in new wall systems.Nevertheless, if you were to get an R-7 per inch of spray foam insulation, you could get an R-23 in a 2 x 4 wall, which has a 3 ½ inch … The Performance method uses software that allows trade offs between different elements of the building envelope. 3 1/2" of the example insulations would have an R-value of 12.5 to 13. I don't think that is a real conflict. Holy cow, there is lots of good advice here but some different opinions. Spray foam insulation comes as a liquid and must be handled … It's a life-safety requirement and long overdue measure for modern homes. I am trying to do my own research and keep finding conflicting viewpoints like this that says closed cell is a waste of money: https://www.finehomebuilding.com/membership/pdf/184243/021269086NRGnerd.pdf. Google "residential exterior wall assemblies". This R value is similar to that of R13 fiberglass battin… Lower Michigan is DOE climate zone 5 - requires R 20 walls in the 2009-2015 IECC. These requirements go beyond energy use to include durability and indoor air quality. I would never flash and batt for many of the reasons outlined here. Raters (and educated builders) brought in late often results in crummy compromises. But that carries it's own added cost. The values are supplied by the manufacturer and the product has to be installed properly. Using spray foam will increase construction costs considerably but these increased costs may be outweighed by the benefits to energy efficiency, and occupancy comfort from reduced drafts. Air Leakage Control: Both low density and high density foam form an air barrier decreasing thermal losses through air leakage. Low density is generally insta… Major mass builders achieve this using 2X6 studs in conjunction with batt fiberglass insulation. Interesting, I'm surprised they permit that level of trade-off. Less framing reduces labor costs. Intersections, windows, doors and other penetrations must be detailed to prevent the penetration of rain water.2, Air Leakage Control: Air leakage is significantly minimized by installing spray foam insulation in the stud space since both low density and high density spray foam act as an air barrier. The thicker wall cavity provides room for R-19 or R-21 wall insulation. Mike - yes 5/8 drywall. If it does not pass, don't pay. This will have both short and long term benefits, your heating/cooling costs will be lower so gradually you will get a payback and as thermal performance is an ever increasing concern should you decide to sell your home it will be more attractive from an energy consumption perspective. Focusing on the walls can be a mistake. You say you live in Va. 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? Different opinions can sometimes both be right depending on individual needs. Affordable, high performance methods are in the current international building codes. I’m curious how he will achieve R60 at the roof and if there is any HVAC equipment outside of the insulation envelope. kitchen cabinets) can encourage drying. Not necessarily. So no real conflict, just right tool for right limitations. Mike - Tyvex is neither paper nor an effective air barrier. If you installed R-21 insulation batts why would you need another layer of exterior insulation? High density foam will inhibit the drying of wet building materials more than low density vapor permeable foam. It gets more confusing when sometimes people quote with the small addition of sheathing, drywall, siding and air films - another 2-3 or so. Have fun building your new home! Springtime Builders - I like the 2nd article best as the author starts off reminiscing about the Maple Leafs winning the Stanley Cup, "ah the good old days". I would stay far away from that builder and architect. This gives you great R-value, a continuous thermal envelope and incredible protection against air infiltration and potential condensation issues. To be clear, R20 is the cavity requirement and R13+5 is an option where 2x4 construction can be used and then 1 inch of rigid foam sheathing on top. i would still use dense-pack cellulose and 2x6 studs. Do your research and ask questions. Just to clarify our R value requirements for exterior above grade wall insulation requirements. You can often achieve proper insulation with a 2x4 wall vs a 2x6 wall with batt insulation and vapor barrier. Two staggered 2x4 frame walls with exterior foam sheets and interior fiberglass or cellulose will get you a better thermal break, higher R value, and a much quieter house than 2x6 construction. Spray foam is the only insulation product that offers a true R-value because it is the only product that … I do a lot of homes in Colorado above 9000 feet elevation where the temperature can get below -20º F with 0% humidity outside. Which would make me question a whole lot more about him and his recommendations. There is more space for … I've always interpreted the codes intent here as a means to address issues such as when one wishes to say increase the % glazing, as this would reduce the overall walls thermal resistance you the had to increase the R value somewhere else to compensate. He’s employed by the building company. Should help make the house even more quiet. Exterior walls in REScheck are defined by the assembly type, gross wall area, cavity/continuous R‑value (U-factor for Other walls) and orientation. It provides a great thermal break, allows you to extend the insulation down to the footing, and you can use 2x4 or 2x6 studs. I think you have a cheap low bidder. Insulation R Value information, view and download. The R-value is a calculation which measures the … A weather/air barrier wrap is not a vapor retarder. Code compliant is the minimum that you are legally allowed to build. Get the RES Check software and try different configurations. It is my belief that it traps moisture and it is a fact that it will crack over time as the building cavity shifts and bends. Unlike the good old days when everyone just had their windows open and their homes could fully breath everyone now lives in a closed up box that requires a fully controlled artificial environment. I'm in the design process of building a home in SW Michigan. Sound is a big factor and this will be a quiet house. Exterior rigid foam is the way to go, in my opinion. The framing component of the wall has zero foam and wood is about R 1 per inch. An alternative configuration would require a compliance alternative approved by the building department which doesn't appear to be the case here. Ask him for a copy of a report of a house he has recently built. The thicker walls also allow additional foam to be placed at the window headers - large framing component. Here are a few resources to look at. Foam salesman and the builders who believe them will claim that foam is about more than R value. Now Michigan may not enforce modern codes yet - there is always a delay. Homes were uncomfortable, expensive to condition and dangerous. My understanding is closed cell foam is great from getting a high R value in a tight space such as renovating an old house. Installed insulation R-value:The installed insulation R-value depends somewhat on the system manufacturer but generally speaking, high density foam (2.0 pcf) ranges between R-5.5 and R-6.5 per inch for the aged R-value, and low density foam (0.5pcf) has an R-value of approximately R-3.6/inch. Where foam is sprayed over large areas of building interiors, its exposed surface should be protected from fire hazard as per your local building code. Builders (and Dupont) like to mention that it helps with air infiltration but it really doesn't when installed in the usual manner. If we install these same three windows packages to the 2x6 wall blown-in with no exterior insulation, we find that the whole-wall R-value … Low density foam allows vapor movement through the foam so other methods of vapor control, such as kraft paper or vapor barrier paint, may be required based on the geographic location.4. It might be economical upfront, it might pass inspection but it does not meet the code's intent. Many products exist to provide this break in the conductivity of the metal, most common is fiberglass reinforced gypsum, like Denshield of Densglass, applied to the exterior prior to the vapor barrier and siding or stucco. Durability Summary: The primary durability risks associated with these wall assemblies involve moisture damage related to rain water penetration. Double stud or exterior foam. Cellulose should also give better sound control. That would be an R value of about 10.5 which is absurd for a house in Michigan. Interesting. Keep-in mind that an R-14 2X4 exterior wall is like building a 1970's house, brand new it's already 40 years old. Improve Indoor Air Quality . The builder in question typically uses a 2x4 open cell spray foam wall assembly of R-14 and R-60 for the ceilings/roofs. They’ll also come with everything you need to insulate an area – whether open cell or closed cell. The low density spray foam wall decreases from an installed insulation R-value of 21 to a whole wall R-value of approximately R-16. This component is roughly 20% of the wall so it will drag down the overall wall to about R-9. What the OP needs to know is that the contractor does not appear to be proposing a wall system that meets the minimum standards of the Energy Conservation section of the building code so he/she needs to ask for proof that it does. lowered the amount of wood used. I don't think there are many high performance builders who use Tyvex as an air barrier. Controlling air infiltration greatly reduces or stops the entry of dust, … Involve the builder and rater during the design stage! We would be happy to discuss the advantages of foam insulation, along with the price difference of batt versus foam with you. We also regularly experience -40 Celsius wind chills). Design and construction are similar to standard 2x6, cost is only marginally higher, yet it provides much better insulation and thermal bridging performance and if done right will also do well on air infiltration (aim for < 1.0 ACH50) and moisture/mold control. There's no dispute that health life-safety is an important element. For example, if you install R-19 fiberglass batts in 2x6 frame walls, with the studs 16 inches on-center, double top-plates, and other elements of "standard" framing, the actual R-value of the whole wall with the R-19 insulation will be about R-15. Zones 7 and 8 R-10 for 2x4 walls; R-15 for 2x6 walls I might be surprised but I'm not sure that here they would permit that type of trading-off. Overall, thermal bridging through studs is reduced due to the higher R-value of 2x6's and less stud area in the wall. And, as mentioned above, WINDOWS (and DOORS)! The answer is: Go with 2x6 walls, air seal it with the proper products and blow in cellulose. As Fiberglass Canada has an R24 batt for 2X6 they can just squeeze in under the radar. You might be surprised how important air sealing and roof insulation are. so that lowers the framing component. Zip walls or taped foam sheathing is a much more effective air barrier. Michigan occupies building climate zones 5 - 7. Loose fill fiberglass is R 14. If the house is constructed with 2x6 studs, the R-value when insulating with open cell foam can reach a maximum of R-20. Assemble a team early in the design process that welcomes this collaboration. The challenge is antiquated construction practices and poorly informed decisions. Keep in mind that R-value* alone does not fully express the benefits of spray foam insulation. Need advice on insulating a 1949 concrete block house. Notice that sheathing needs to be thicker for 2x6 walls. The warm moist air inside wants to migrate to the outside. Certainly from my past direct involvement in code our codes in most areas were very closely aligned with the major US codes. It is often used for roofing on commercial buildings. ... (Sub roof & external walls) Sub tile roof (Spray to Sarking, Anticom blanket) Sub colour bond roof (No sarking required) Under floor acoustics (Ground to 1st floor) External walls (Cavity injected or sprayed) Home theatre acoustic insulation; Shipping container built homes; Existing … If the builder/owners do not have time to do the research, it is imperative that an architect current with the latest techniques, but not married to the idea that the latest is always the greatest is best is employed. Next and likely best for most people is a double (offset) 2x4. Sure the foam gives an air barrier but good details and exterior foam taped should be good there. That seems like weak wall performance for Canada. Here is a visual guide of batt installation quality. board) since the other elements of the wall system don’t count. This is because the extra cavity insulation makes it tougher for the insulative sheathing to keep the framing warm. I am waiting for those numbers right now. There are often no measures taken to sheath the exterior to prevent cold or heat from being transmitted through the studs and into the home (or business). Agree with ionized, almost all new construction should include a 3rd party energy rater, the most common certification being Energy Star. He does, however, pass code using the performance method as opposed to prescriptive. He claims his homes usually are at two air exchanges per hour. The R20 I referred to was for below grade situations such as basement walls, my apology. If the walls are lightly insulated the other elements must be more heavily insulated. Marine Zone 4 R-2.5 for 2x4 walls; R-3.75 for 2x6 walls. Installed insulation R-value: The installed insulation R-value depends somewhat on the system manufacturer but generally speaking, high density foam (2.0 pcf) ranges between R-5.5 and R-6.5 per inch for the aged R-value, and low density foam (0.5pcf) has an R-value of approximately R-3.6/inch. Will you be using 5/8 inch sheet rock on the 24 inch on center exterior walls? There's no doubt that thermal performance and moisture/vapor control has been a major concern, ever since the 70's energy crisis when they started to tighten up homes. All of these and more are factors that should be considered when deciding what wall system to build for your specific Climate region. Where is Worthy? I'm still curious about the roof/attic insulation and how it is installed. Also you can run loomex in the interiour 2 by 4 wall and not have to worry about it being buried 4 inches deep in foam. 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