Sleek showers replaced tub-shower combos in these bathroom remodels. The requirement for Zones 3 through 5 (most of the US) is R-20 cavity insulation or, alternatively, R-13 cavity insulation plus R-5 continuous exterior insulation. Sometimes nouveau construction techniques are disasters as they age. Batts are typically the poorest performing type of cavity insulation. The most recent Building code may not even be adopted yet in your area or the building code may even be outdated based on current building science. 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The IRC, if it applies, only lists two kinds of exterior wood framed wall insulation applications: 1) cavity insulation and 2) cavity + continuous exterior insulation. I’ve used all 3 methods. That is true when it comes to air sealing but R value is R value and code specifies R value. Finding a contractor who is used to doing that and doesn't overcharge for the additional effort can be a challenge. Since buildings insu-lated with the listed “maximum thickness” of spray foam often fail to meet minimum prescriptive R-value … Spot spray foam, zip sheathing and tape etc is more cost effective. As you are most likely aware it goes beyond just the building envelope, as they tighten this up indoor air quality and interior humidity control becomes an issue, more equipment and more cost. We are proficient in SIPs, the ultimate in wall and roof performance per inch of thickness. Notice that sheathing needs to be thicker for 2x6 walls. I do a lot of homes in Colorado above 9000 feet elevation where the temperature can get below -20º F with 0% humidity outside. Ok rant done. This varies between R22 and R29 depending upon the efficiency of the installed heating equipment. ft. cinder block lake cottage. The difficulty in being able to properly advise the OP is the fact that we do not know the actual proposed completed exterior wall system. Spray foam insulation comes as a liquid and must be handled … If you use one of the latter you should also pay very close attention so sealing all air gaps in the wall assembly. You can often achieve proper insulation with a 2x4 wall vs a 2x6 wall with batt insulation and vapor barrier. Humid air flowing through or within these voids results in mold and mildew on cold framing components. I wasn't expecting this many responses but have learned a lot through the various opinions and recommendations. Learn the material options, costs and other factors when replacing or updating your siding, Great home project: Replace your windows for enhanced style and function. I don't think that is a real conflict. Assemble a team early in the design process that welcomes this collaboration. In a 2x4 wall you can use spray foam but it has to be closed cell not open cell. Spray foam is the only insulation product that offers a true R-value because it is the only product that … Loose fill cellulose is almost R 20. Have fun building your new home! The R22 Wall A typical constructed R22 building wall using framing 16” on centre with fiberglass batts is as outlined below: Assembly … Insulation R Value information, view and download. Here's a good BSC article about vapor barriers written by a famous Canadian building scientist. In NC (zone 4 but 10 miles from zone 3), I am doing 2x6 with cellulose and R-3 foam on the outside. Certainly from my past direct involvement in code our codes in most areas were very closely aligned with the major US codes. 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. Both approaches come at a higher cost in both labour and the installed price of the spray foam material. High density foam will inhibit the drying of wet building materials more than low density vapor permeable foam. I love Roxul as its simply better quality than most reg fiberglass batt insulation, and very good as sound insulation also. He claims his homes usually are at two air exchanges per hour. Complex two dimensional heat flow analysis and one dimensional hygrothermal modeling were used to determine moisture related durability risks for analysis. Some of the suggestions above could cause trouble because the insulative sheathing is too thin to keep the osb/ply and framing warm enough. What I find ironic is builders are required to have install walls and ceilings with R-20 and R-49 insulation values, but then are allowed to install HVAC equipment in unconditioned attics with R-8 flexible duct work. To meet R-20 requirement (if that is what code says in your location). Because the home really needs to be designed as a whole system and not field adapted to different construction methodology. In most attics/roofs you can't get that level of insulation around the perimeter so the R-60 will not be consistent over the entire ceiling. Air infiltration is very important but can be addressed in a lower cost way. The R20 I referred to was for below grade situations such as basement walls, my apology. 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? I might be surprised but I'm not sure that here they would permit that type of trading-off. Fiberglass batts are R 17 to 18. There is more space for … Insulation is rated in two ways, R-value and U-value. IMO - it is a way to cover sloppy work and still get decent numbers. Now Michigan may not enforce modern codes yet - there is always a delay. Not generally something to strive for. As the industry adopts these crucial details, relative costs equalize and health improves. I have heard so much BS from builders, inspectors etc regarding insulation that I would just nod your head and ignore them as generally non experts on the issue. I am looking to buy a 720 sq. You know, in case you … You say you live in Va. i would still use dense-pack cellulose and 2x6 studs. JDS - That's the type of information needed to properly assist the OP. An easy solution to the OP's concerns would be Huber's Zip Insulated R-Sheathing. This gives you great R-value, a continuous thermal envelope and incredible protection against air infiltration and potential condensation issues. I haven’t used 2x4 studs since the mid 70’s. Zip walls or taped foam sheathing is a much more effective air barrier. 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. Technology created the problem and now we need more technology as we attempt to overcome the problem. With any of these products it pays to get someone who can install the insulation correctly ensuring no voids or gaps. The bulk of new single family residential homes here in southern Ontario would require a minimum R value of 24 based upon the insulation only and the fact that heating equipment greater than 90% efficiency is mandatory. You should ask the contractor for the applicable Evaluation Service report for the proposed foam insulation and it will tell you the R value for a given thickness. He has, however, been very open to my ideas and questions with efficiency and is willing to do whatever I want. If the walls are lightly insulated the other elements must be more heavily insulated. There are other construction methods but for the mass builder this is the most economical and fastest method to meet the code minimum concerning R value. For some of the prescriptions, like blower door minimums, it's cost-effective to exceed code. To prevent the vapors from becoming water there must be no air within the wal or ceiling cavities. Outdoor air ventilation is now required by current IRC codes and a smart idea for any inhabited enclosed space. There are people who do studies using Science to answers these questions. Blower door test results are currently more important than R-value. Sprayed foam insulation in the same wall cavity can range from an R-14 to an R-28 depending on the product that is used. Foam salesman and the builders who believe them will claim that foam is about more than R value. Much better today but not perfect. Even leaky, all natural homes can have poor indoor air quality. The R value of 9 that I quoted above is the "clear wall" which is factoring in framing component. Spray Foam Insulation possesses the highest R-value over any other insulation. ... (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 … Will you be using 5/8 inch sheet rock on the 24 inch on center exterior walls? The dew point, the temperature at which vapor turns to liquid will move through the building envelope pretty constantly. They can perform fine under the right conditions but as cavity-only insulation with no regards to air leakage they are not the best choice with current state of affairs. Seems like a very minor cost to bump up the walls performance. But if you were stuck with 2x4s and no exterior sheathing, the closed cell makes more sense. That would be an R value of about 10.5 which is absurd for a house in Michigan. In respect to indoor air quality this is the direct result of man made materials and the adoption of ever tightening air infiltration requirements. Spray foam insulation kits are a great choice because they can insulate all sorts of spaces from wall cavities to floors. Durability Summary: The primary durability risks associated with these wall assemblies involve moisture damage related to rain water penetration. The biggest insulation issue a steel framed building has is the lack of a thermal "break". After a ton of geeking out about wall assemblies, including reading lots of articles and speaking with insulation experts, builders and energy consultants, my favorite assembly is nail base insulation (Zip-R or Atlas nail base) on 2x4 or 2x6 framing with about 3" of spray foam. No, no, no to open cell foam in your area. I have seen pictures of improper installations. En savoir plus. Find your zone on the map and then use the above insulation R-value chart to determine the level of insulation you need to properly insulate your attic, walls, floors and crawlspaces. If space is tight, and you can only install a thin layer of insulation, closed cell foam is by far the better choice. Code compliant is the minimum that you are legally allowed to build. 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. Very rarely do we insulate the exterior walls of new homes using spray foam (cost being the main factor). Involve the builder and rater during the design stage! When comparing spray foam insulation vs fiberglass insulation r value, you get more insulation value with foam. Spray foam will yield an R-7 per inch. This increases the durability of the wall system considerably over standard construction.3, Vapor Control: High density (2.0 pcf) foam forms a vapor control layer reducing vapor movement through the enclosure, minimizing the potential for wintertime vapor condensation and summertime inward vapor drive. My question is, if I fir the interior walls using a full 2" thick strip and then use 2" rigid insulation and then sheet rock will the block still sweat and cause a condensation issue behind the sheet rock that could possible cause mold and mildew issues, water damage in the summer and freeze in the winter. Code requires this wall assembly to have 2 layers of gypsum board on the interior Dense spray foam is installed differently so that lowers the framing component. Ventilation behind vapor impermeable claddings and interior components (e.g. Spray foam significantly reduces risks of poor air tightness detailing of the exterior sheathing or interior drywall. Here is a visual guide of batt installation quality. I’m curious how he will achieve R60 at the roof and if there is any HVAC equipment outside of the insulation envelope. Could this be an option for you? My entire home is insulated with Roxul (2x6 walls with 1.5 " exterior extruded foam to combat thermal bridging. Air Leakage Control: Both low density and high density foam form an air barrier decreasing thermal losses through air leakage. Good luck! Drying: Spray foam walls dry relatively slowly if water enters the enclosure, since they do not experience convective looping and air movement similar to air permeable insulations. I'm in the design process of building a home in SW Michigan. These R-values are a sum, meaning this should be the total R-value once you add up the entire depth of insulation. These requirements go beyond energy use to include durability and indoor air quality. How to Achieve R-21 in a 2x4 Wall. Typical Insulation: Low density 0.5 pcf foam, or high density 2.0 pcf foam. The bigger problem is that batts almost always results in substantial gaps and voids. 3 1/2" of the example insulations would have an R-value of 12.5 to 13. Is this a tract or builder's home, or a truly custom home? Unlike other forms of insulation, spray foam can form an air barrier without the use of additional products. I have built and remodeled a few home so I think I understand the challenges and options of insulating the ceiling but my concern is exterior/interior walls. The R-value of the high density spray foam wall decreases from an installed R-value of R-30 to approximately R-20, a decrease of R-10 because of thermal bridging. And, as mentioned above, WINDOWS (and DOORS)! with 5" high-density spray foam cavity insulation. It goes up faster than exterior foam board over OSB, provides a good nailing base for classing and avoids the need to furr out around windows and doors. But it is never installed correctly. According to a local insulation company, the cost difference between installing R-15 to R … 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… Air barriers do not account for insulation voids and thermal bridging of framing components. With that said, I would probably go with 2x6 in any MI climate, just be sure it has enough insulative sheathing R-value to keep it dry. kitchen cabinets) can encourage drying. I live and build in the DC area and we have the worst of both worlds, high humidity and freezing temps. Both walls are affected by Most raters are not keen on getting too far away from code prescriptions. When I factored in 25% of the sf for windows and doors at U=.3, I saw the R value delta between standard 2x6 construction and the Bonfig wall drop from R5 to R1.2--leading me to abandon the Bonfig wall for traditional 2x6. Spray foam in walls is costly and unnecessary since the rigid foam can do better at stopping infiltration. density spray foam inside the framing to achieve the R22 value. 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. Zone 6 R-7.5 for 2x4 walls; R-11.25 for 2x6 walls. Rein in your desire for a home "now"...or regret it later. This is because the extra cavity insulation makes it tougher for the insulative sheathing to keep the framing warm. Easy Foam Sydney's insulation experts. Likely meet these code requirements many of the reasons outlined here installed deliberately overflowing cavity. 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