optional walls insulate with fiberglass batts against rigid foam. For example, if you live in zone 4, it says you need a minimum of R-10 on the walls. However, special care should be used when insulating concrete (or block masonry) basement walls. It only takes a minute to sign up. Asking for help, clarification, or responding to other answers. A footnote explains this notation as follows: "15/19” means R-15 continuous insulation on the interior or exterior of the home or R-19 cavity insulation at the interior of the basement wall. – Ron B. "15/19” shall be permitted to be met with R-13 cavity insulation on the interior of the basement wall plus R-5 continuous insulation on the interior or exterior of the home. If I am going through 1" of foam, and 1.5" of lumber, that only leaves .5" actually in the concrete, which does not seem like enough. Obviously thicker is better but it is also more cost prohibitive. Secondly, when installed directly onto basement walls, foam provides a continuous layer of insulation without cracks and crevices. What are you doing on the floor? What do you think of cement lap board for siding? If you plan to insulate your basement walls with spray foam, the best approach is to frame your 2×4 walls before the foam is sprayed, leaving a gap of 1-1/2 in. First, find your climate zone on this map: Then cross-reference that with the table here: http://publicecodes.cyberregs.com/icod/irc/2012/icod_irc_2012_11_sec002.htm. @DMoore I am in the souther indiana region. We have the vents permanently closed in the winter. As the how thick foam board for basement walls has a quiet room environment, it will be therefore much fun to enjoy your forgive become old there behind your family and connections to locate the silence after a hectic noisy office day. Framing should be 1/2-1" from wall, moisture will have plenty of run to ventilate, and unless you have a leak you will never have issues. I would shy away from powder actuated fasteners for this. Round up to 3 inches. I’ve also read that nominal insulation for the basement walls should be between 15 and 20R. * Although in theory 1" is enough foam, more is better--gives you less chance of summer Once you are bothering to put in foam, you might as well put in at least 1.5" to reduce the chance of summer humidity condensing on cool studs. At 1.5" polyiso or EPS (both blown with much more benign pentane) would always be well above R5, and don't suffer the long term decline seen with XPS, and don't depend on retention of the blowing agents for performance. The material can be made from polystyrene, polyisocyanurate, or polyurethane. rev 2021.1.18.38333, The best answers are voted up and rise to the top, Home Improvement Stack Exchange works best with JavaScript enabled, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us. Become a GBA Prime member and get full access to GBA articles, enyclopedia, videos, CAD library, and more. why is user 'nobody' listed as a user on my iMAC? XPS (blue or purple and smooth) is R-5, so you could get away … What I have been doing for 4-5 years is ROXUL on the walls starting with one foot below grade, stuff all the joists and outside walls with ROXUL and spray foam (cans) for gaps. Where can I find Software Requirements Specification for Open Source software? Just install drywall right over the insulation using Tapcon screws going into the concrete wall behind the insulation. x 2 ft. x 4 ft. Stucco Grey Foundation Panel. There are three key issues with foam sheathing: 1) Use a thick enough layer of foam to minimize condensation on its interior face. between the bottom sill and the concrete floor. Polystyrene foam (which is what both XPS and EPS are made of) will ignite and melt at relatively low temperatures. Save time and space in your basement with Owens Corning FOAMULAR® INSULPINK® extruded polystyrene (XPS) insulation. RIght at the border of 4 and 5 on the chart below. a 6 mil poly barrier before drywall will prevent your wall from drying, hopefully your municipal building inspector will let that pass if you're dealing with one. How can I use Mathematica to solve a complex truth-teller/liar logic problem? I finish 7-10 basements a year and have just done 2 in the past 4 years for my own home. rigid foam board in basement with exterior guard overkill? It's not a structural studwall- it's not holding up the house and has fairly minimal forces acting on it. The problem is I cannot find powder-actuated fasteners longer than 3". Q. Aaron, Thanks again for all the help I'd rather do the job right the first time! Avoiding Basement Insulation Mistakes Be The Pro. On July 14, 2020 By Amik. Here at Concord Carpenter we strongly recommend using Closed Cell spray foam to insulate a below-grade basement wall. In the long run, the energy savings make up for the costs of the insulation. Secondly I am wanting to cover the foam that is exposed, and maybe even below grade if it adds benefit. Closed Cell Spray Polyurethane Foam (CCSPF), when installed properly by a trained professional, can be the best … The best rated foam board insulation product is the FP Ultra Lite 1 in. FAQ: Why Do Some Builders Avoid Foam Insulation. In zone 5, put at least an inch of EPS or XPS between the bottom plate (or any wood subfloor) and the slab, as a thermal & capillary break- a mere 1/4" doesn't cut it. optional walls insulate with fiberglass batts against rigid foam. (Note that many brands of foil-faced polyiso have a foil facing on both sides.). With nothing pushing it out it may not need any fasteners in the bottom plate at all- you might use blobs of foam-board construction adhesive to glue the EPS to the slab & bottom plate, but a few nails or TapCons should keep it in place in anything but a serious earthquake. I believe Home Depot sells 1-3" sheets of both EPS and XPS so you should be able to find what you need there. This won't delete the articles you've saved, just the list. Can ISPs selectively block a page URL on a HTTPS website leaving its other page URLs alone? Spray foam insulation is available in open cell and closed cell. Foil faced polyiso is also easier to air-seal reliably than XPS, using high quality foil tapes. Go with either tapcons or the Hilti press-in fasteners made for this purpose. Aaron, Divide that number by the per-inch R-value of the foam you want. After the rigid foam has been applied to the wall, apply pressure for 30 seconds. (The colder the slab, the higher the chance of condensation.). Aaron, The product you reference is 1/4" thick and only rated R-1 per board. frame your wall against the rigid foam with a thermal break of foam (1/4″?) 168 Posts . In fact I have not heard the sump kick on unless I forced it on and we’ve had some significant rain since I’ve lived in the house. Without Studs, when you do interior walls do you just push the framing up against the exterior walls and connect the drywall? You can wait to do this as long as you're comfortable with, or as long as your inspector allows you to, if this is an inspected project. Lastly, and maybe most … Foam Board For Basement Walls . XPS (blue or purple and smooth) is R-5, so you could get away with only two inches of XPS. How to insulate basement walls finished basement wall panels basement wall insulation options basement ceiling insulation waterproofing is crucial when finishing. Were you planning on putting any foam on the rest of the concrete floor, or just under the walls? "If so, what direction should the faced side be oriented (to the concrete to the interior)? But before I glued the foam board to the walls, I painted them with some of that white Drylok paint specially designed to seal against moisture leaks. Exterior Walls; Basement and Crawl Spaces; Floors (over open or vented spaces; Interior Walls and Floors; Exterior Walls. What thickness of closed cell spray foam should I use on my basement walls? It is recommended that you install foam board insulation for exterior walls of concrete, foundations, concrete slabs, basement walls and crawl spaces. If you use foil-faced polyiso, and if you are able to have the foil face an air space, you will gain about R-1 or R-2 of extra R-value for the total assembly. Just make sure everything's sealed up tight so no inside air can reach the walls and rim joists. How many dimensions does a neural network have? Seal them to the floor too. Thanks in advance for reviewing my question. Even if it may have performance issues dropping to R4 at the colder above grade portion during the coldest part of a zone 5 winter, it's higher performance as the temps warm up (and at the below grade section) ensures that nothing bad will happen- no mold/rot in the studwall. To learn more, see our tips on writing great answers. How Thick Foam Board For Basement Walls. If you're using low-density Home-Depot-sourced R-3.8 EPS foam (a sheet of white beads, like styrofoam), that means you need 2.7 inches of EPS to be code-legal and safe. between the bottom sill and the concrete floor. We are ready to insulate the walls and are going to use closed cell spray foam. Can rigid foam board have an air space between it and the studs. Is it safe to keep uranium ore in my house? I am in central Indiana. The beauty of foam for basement walls is; – closed cell foam insulation does not absorb moisture and therefore will not contribute to mold growth. Before you start insulating your basement, you need to decide what kind of insulation to use. It would be much more cost-effective to buy a single 2 or 3" board. Using fiberglass batts in conjunction with the spray foam and with a water vapor barrier, you will have a nice, dry, warm basement. Basement walls - gluing foam/drywall. Martin, my copy of 2012 IRC says 15/19 for basement walls in zone 5. Then, repeat the process. Getting around to finishing my basement, I had some water issues previously but solved them by installing an interior french drain ( weeping system ) in to my sump pump and new gutter system. If you want to install carpeting in a basement, you definitely need a layer of rigid foam (either under the slab or over the slab). Install 2″ insulation foam boards in a vertical orientation, tight to the floor and top of wall or joist bay. As far as the floor....well that was going to be my next question. Insulating basement walls is a big job, but it’s definitely one you can do yourself, maybe with the help of a friend or relative. What is the best rated foam board insulation product? Building codes will tell you this information. We ensure that the boards fit together using the factory joints, and then return later to tape all seams. But XPS is more expensive per R-value, worse for the environment, and degrades to R-4.2 over time, so in general, EPS is preferred. Foam Board For Basement Walls. Minimum foam thickness for basement floor, Minimum continuous insulation thickness vs. fastening requirements. Insulating a basement properly is rather challenging in cold climates. A foam board sheet between the inner and outer walls of the basement allows moisture to evaporate, preventing damage to paneling and drywall. If you're using low-density Home-Depot-sourced R-3.8 EPS foam (a sheet of white beads, like styrofoam), that means you need 2.7 inches of EPS to be code-legal and safe. What is the "Ultimate Book of The Master". On January 16, 2021 By Amik. This feature has been temporarily disabled during the beta site preview. If you insist on framing a wooden wall over the foam, use pressure-treated lumber. It comes in standard-size 4×8 sheets, and smaller sizes, in many different thicknesses from 1/4 inch to 2 inches. I’ve installed thousands of the things, and I’d never try a long one through foam. Seal the edges of the boards with little bits of spray foam, caulk, and tape (as appropriate). Additonally is there any concenrn with insulating a few moths prior to framing aside from aesthetics? DMoore: Thanks for comments on XPS not being attached to drywall. Discussion Starter • #1 • Jan 9, 2012. Tags: Basement & Foundation. Making statements based on opinion; back them up with references or personal experience. It has been invaluable for planning my basement finishing project. Now it's all R6-ish.). For more information, see How to Insulate a Basement Wall. How to limit the disruption caused by students not writing required information on their exam until time is up, 9 year old is breaking the rules, and not understanding consequences. Avoiding Basement Insulation Mistakes Be The Pro . To finish basement walls, you'll need to prepare the walls first, install insulation, apply a wall frame, and install drywall before you can decorate them. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. * Use EPS or polyiso on the walls. As far as flooring goes my wife wants to mimic the upstairs as much as possible and that means carpet in bedrooms (there will be 2 in the basement) and hardwood (or something close) in the halls and high traffic areas. Conditioned basement space has a never-ending battle against moisture gain and heat loss. With the help of the correct gear, it is easy to insulate the concrete exterior wall without requiring any help from an insulation specialist. Choose Your Insulation. All foam board insulation can be shipped to you at home. That would be about 2.5 inches of polyiso, 3 inches of XPS, or 4 inches of EPS. The R-value of open cell spray foam is about 3.5 per inch, although the R-value can be different depending on the product. I currently am focusing on one sticking point. Fully derated 1" polyiso will come in over R5. That's the minimum R-value you need to be safe. Foam board has various thickness and R values. If no, why not use a sill-seal rather than foam? Basement Foam Board Insulation Pros: Some rigid foam products are water-resistant that can help limit moisture buildup and mildew growth. You’re almost guaranteed to have overpenatration issues, and getting the fastener straight enough to not ricochet off the wall will be very difficult in a material that is both thick and soft like foam. Why are "LOse" and "LOOse" pronounced differently? I recommend using cementboard instead of drywall for the bottom few feet for flood resistance. How to install rigid foam insulation on eps xps foam insulation styrofoam insulating basement walls in canada insulating basement walls in canada to install insulation without drywall. Using Closed Cell Spray Foam to Insulate a Basement Wall. Another option is to switch from power actuated fasteners to concrete screws. Do both XPS and EPS offer vapor protection or is a vapor barrier preferred? I've given you a method to make a wood-free basement wall that is flood-proof. (Polyiso used to, when it was blown with CFCs, starting out at R8-10/inch and eventually dropping to R5.5-R6. The info that iLikeDirt is giving you is for basements. Insulating your basement walls with the right material can help make your basement warmer and drier. relatives room or karaoke is afterward awesome. I've had two different contractors come out and recommend different thicknesses for the foam. I’ve never had a water issue in this basement (in the 2 years I’ve been there and previous owner did not for the 5 years he was in it and he was the builder of the house in 2008). © 2021 The Taunton Press, Inc. All rights reserved. Round up to 3 inches. site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. All that being said I still want to be safe than sorry. foil)"? I also used rigid foam board on my basement walls before putting in studs, insulation and sheetrock. Follow this step-by-step guide to get the job done right. They are slower to install, but yield a lot more holding power and you don't have the problems of bent nails and spalling you often get trying to fasten to old, cured slabs. Going Beyond 2x4 Walls In A Warm Climate Energy Vanguard I have insulated my basement … Adding Insulation To Basement Walls … I agree with Dana: Also without the framing do you just typically mount recepacles on the outside of the drywall? If you want, you can drill through a concrete slab with a concrete bit to see what's underneath the slab. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. A. If only half-inch penetration bothers you, put thinner EPS (or XPS, but not polyiso) under the bottom plate as well as any cut bottom edges of any wall polyiso to keep the wood or polyiso from wicking moisture up from the slab. See below for a shopping list and tools subscribe to this old hou. My typically sized basement took about 35 … If you are installing furring strips or studs without any insulation -- in other words, if you are creating an air space -- then the foil should face the air space. Otherwise, it doesn't matter. and then leave a small gap between teh XPS and the studs/drywall? If yes, then I'd suggest framing the walls on top of the subfloor and foam. Prior to installing the next insulation board, we add a thick bead of adhesive in the edge groove. Estimated savings for R-10 insulation range from $250 in Washington DC to $400 in Minneapolis. Do not add a dedicated vapor barrier like a sheet of plastic or anything. Who must be present at the Presidential Inauguration? The other said 2" against the walls and 3" in the sills. Some types of thicker foam board insulation are available, but they may need to … As you can see, insulating basement walls with foam board boils down to just four simple steps. foil) and if so what direction should the faced side be oriented (to the concrete to the interior)? The thermal performance of 2x4/R13 + R5 c.i. For interior partition walls, use mortared 4" concrete blocks covered with a skim coat of lime plaster gauged with a little gypsum in it. The fastener only has to penetrate enough to keep the wall from walking away from the foundation over time. The OP's proposal is specifically allowed (which doesn't mean it is good). So far my research has told me to do the following: use Drylok on the basement walls use xps rigid foam adhered to the concrete walls (tape and seal gaps and cracks) frame your wall against the rigid foam with a thermal break of foam (1/4″?) That 's the minimum R-value you need to insulate below grade, as the summer of. 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Foam with a thermal break of foam board insulation Pros: Some rigid foam board on the proper.... Thousands of the great info on this site ; interior walls and rim joists,! Cement lap board for siding border of 4 and 5 on the chart below the costs of the.! Finish my walk out basement so i ’ ve been doing my research on walls. To do how thick foam board for basement walls the Floors in order to have carpet and wood as flooring steps. Insist on framing a wooden wall over the insulation exposed for a,... Install foam board when insulating a basement wall sure everything 's sealed up tight so no inside air can the! Rated R-1 per board border of 4 and 5 on the assumption that there is (... Grade if it adds benefit the list that can help protect walls from moisture problems, but they may to. Is for basements grade if it adds benefit right the first number under `` ''... Corning FOAMULAR® INSULPINK® extruded polystyrene ( XPS ) insulation masonry ) basement walls the! At least 24 inches in height 'd suggest framing the walls and/or floor be faced i.e! 2″ insulation foam boards in a vertical orientation, tight to the interior ) the carpet fasteners to screws... My house, insulating basement walls before putting in studs, insulation and.... Moisture to evaporate, preventing damage to paneling and drywall slightly preferred because you can multiple. Cad library, and more the chance of condensation. ) superior effective R-value inch... Insulation for the walls minimum R-value you need a minimum width of 20 inches at. There is no need for wood at all, and then return later to tape all seams orientation.