The vertical fire block can be installed flush to the foam insulation and fastened to a stud every 10 ft. Ok. I'm in NJ. My plan is to finish off about 3/4 of the basement area. If you want help with or more information about the issues we blog about, then let’s talk. My question is how much space should I leave between the studs and the insulation? Batt insulation? Many come with tongue and groove joints but either way I recommend putting a bead of polyurethane or acoustic sealant or spray foam between each panel and around the wall parameters and sealing all seams with tuck tape. Help ! If I put the silver foil side to the cement wall, do you think I can use EnerBond foam adhesive ( which is recommended for Thermax), or do I have to use a foam caulk type adhesive like PL300 from Loctite? I assume you covered the pink board with drywall? Some people erroneously state that XPS is the vapor barrier. It comes in rigid panels that can be cut to fit the space needing insulation. I am in the pre-planning phase of finishing my basement. If you don't have one, this Stanley is under $10 and gets great reviews. Curious question: if you are covering foam board with a 2x4 stud wall filled with Roxul, then is a minimum 1/2" of sheet rock still required on face of stud wall or would a 3/8" sheetrock be permitted because of the use of Roxul inside the wall cavity? If so, which one? Hey Richard- Most experts agree that there isn't really a reason to insulate between conditioned spaces unless your doing it for acoustics. I’m working with a local carpenter to finish my basement. We are going to finish the basement and remove all of the old insulation (we've seen some small skinks/lizards hiding in there as well as on our porch), and we want to use XPS boards along the walls before studding out and drywalling. To help prevent this, enough insulation must be applied to create the required thermal break, and this is typically considered to be ~R10. Hi Ken - I afraid I can't give you any educated answers for stone walls. The problem is the room is only 5' wide so we don't have room to build the frame for the wall board installation. I live in a brand new home (under 1 year). If you remove the nails from your foundation walls be aware you may have just opened leak paths. Personally I'd recommend 5.5" of Roxul to cover the foam because it's a fire barrier, good insulator but air permeable, is pest-resistant, mold-proof, water resistant, and has good sound dampening properties. After cleaning all the mold, determine if you have a moisture problem before installing a new wall. Do i need to put drywall on top of this insulation or can i just put something decorative? The idea is to ensure that the walls are as smooth as possible so that the rigid foam adheres properly to the wall. I'll never use fiberglass batt again! (Hopefully Amex wl step in and I will get some of my money back). The draft stopping has to bridge the space between a stud wall offset from the foundation wall, and has to run parallel to the studs... i.e. 4. Thanks a lot. it looks like a good way to save space. Basement Foam Board Insulation. In either case, full the std cavities with mineral wool like Roxul and NOT fiberglass insulation. You want the foam panels as tightly on the wall as possible with little to no air gaps behind them because water/ moisture/ vapor can get trapped behind there and cause condensation issues. Additionally, one corner under the house is a near "mini basement/workroom" with almost 6 feet of headroom, about 350 sq. - First off, I made sure there was no moisture problems to begin with. I'm at insulation, drywall stage. Frame an interior 2x4 stud wall at 24 inch centres, pressed tightly against the foam panels. Anyway, I want to build the rest of my framed wall off of those, so all I need is the studs and the bottom, treated plate. Foam board insulation – The first basement insulation that we recommend considering is foam board insulation. Read up on it on Build Science Corp's website. Some have started incorporating pesticides in the foam, however. Hi, thanks for your informative website! from the ceiling (well the fire blocking under the floor joists) to the floor. Would you recommend following the contour of the wall with xps, and tape all the seams, rather than leaving a gap behind the XPS and the wall on the upper half? I like this type of insulation because it will help me get the most space possible. One to two inches of rigid foam will be a solid moisture deterrent. Given its the lowest 2 feet, you probably don't even need to replace it unless you have a walkout basement. I plan on attaching 1 inch foam board insulation to the concrete wall and seal all seams with tuck tape. If you're not concerned about losing too much headroom you could install rigid foam with OSB on top. climate zone, you may be required to install a vapor barrier or smart membrane that conforms to code on the warm side of the wall. -Jason, Can I use styrofoam insulation between the joists in my basement. The first thing I learned, and probably one of the things most people overlook in trying to make their basement more comfortable, is that you need to insulate the rim joists. Is the foil faced rigid board the PolyISO that you mention? I intended to finish the basement fairly quickly and had one side framed in , but that's as far as it got. Frame the 2×4 wall before the spray foam is installed, with a gap of about 2 in. You can't just throw any ole insulation up. I have been said that the XPS is flammable. Can I apply paneling to the rigid board? Thanks!!! I live in Minnesota, and am currently finishing my basement space, a 1951 single story rambler with block wall foundation. I was planning on also using spray foam or cut pieces of XPS in the rim joist area. Be sure to clean very well. It did OK when scoring along the 4' lengths, but not to well along the 8'. This job is certainly low on the DIYer difficulty scale. If so, how? The floor and the wall do not meet at square edge-- a bit curved. For attaching to the walls, I plan to use some adhesive, but also use plastic fasteners, probably two per sheet. Call 1-855-350-4256 today! Lastly, all XS and EPS foam, be it on the walls, on the floor/ slab, and in between the floor joists bust be sealed in with a thermal (fire break) such as 1/2" drywall. Thanks, We have a room in our finished basement that we want to put rigid insulation onto to keep the cold out. However, using a GPS rigid foam like Halo® Interra® doesn’t require attachment via cap nails, staples, etc. My question is; do I need anything additional to the paint and XPS/spray foam/tape to ensure a good vapor barrier? Apply sealant to edges of xps and don't need to tape? Foam board insulation is easy to cut with a circular saw with a masonry blade or scored with a utility knife and snapped like you would drywall. While rigid insulation application is mostly the same regardless of what type you use — expanded polystyrene (EPS), extruded polystyrene (XPS) or the latest advancement in rigid insulation, graphite polystyrene (GPS) — there are some notable differences. With that requirement, what's the point of using XPS? Prep Work - I've talked about basement waterproofing paint before. Good luck to anyone trying to figure out their insulation, I still don't know what to do, haha! I'd like to add insulation and figured batt insulation made the most sense since the walls are already framed, but wasn't sure if I need a vapor barrier or something else between the batts and the wall. Pretty low on time commitment too. Thus, I need to add an additional R8 to R10 of insulation into the wall cavity. I am hoping you are still actively reviewing this website! So the basement walls that are under these protected areas have always been very dry. After a ton of research, I have found so many conflicting theories on the best way to insulate a basement. And I've read that with the foam board on the concrete I should NOT use poly vapour barrier between stud wall and drywall. Most homes use fiberglass, but rigid foam insulation, although more costly offers a few extra features. I've contended that at some point, every basement is susceptible to water. The trick there is to make sure you have the proper density to ensure adequate thermal capacity. Problems arise when people don't insulate properly and/or use the wrong products for their application/ situation. We ended up having to cut sheets into smaller sections to get them to cooperate = added install time. 2) If using XPS foam board (which has a 'vapor barrier'), and I live near Chicago, what do you recommend between studs? Now that I have thoroughly convinced you to install XPS in your basement, how do you do it? XPS HFC Bans Won’t Matter When You Use Halo. Question is, was your drywall placed directly onto the concrete?? First we install two inches of rigid foam board insulation (closed cell). Hi Jen - Yes, one downfall with the XPS is you will loose some space in the room. Hi. Good luck! I was going to put in new flooring( as soon as I feel confident what flooring is not I believe the author also mentioned that about a tube per board was good. Can I put XPS on the joist over existing batt? the basement is small. So unfortunately my contractor and I have parted ways, and he's got my money. You don't want cold water vapor to meet warm air. DON'T use XPS foam panels in your situation = epic fail. Finally, simply apply the rigid foam to the wall, starting at the slab and then pushing it back toward the ceiling joists as in the image below. Do I need to chip down the concrete form seams so the rigid foam board fits flush with the concrete wall?? Drywall Saw - Not 100% required but I found that with 2'' thick XPS, the box cutter did not sufficiently score the XPS to be able to snap pieces off. If you have a newer home, you may actually already have XPS on the outside of your foundation. I am planning on using Dow Super TUFF R glued to my basement walls, with 2 x4 framing up against the TUFF R. I wanted to use THERMAX, but can't find locally. It also offers continuous insulation, greater R-value and won’t lead to mold … Thanks Adam - so just to clarify - you say you lost 1.5" for framing - can you share a bit about how you framed? XPS - Duh! One wall is against a partially finished basement. Any suggestions? Would this be a correct statement? Lastly, and maybe most importantly, at two inches or thicker, closed cell foam insulations qualify as vapour and air barriers. Don't you need to add drywall on top? The other is against the garage wall. But that XPS foam in your rim joists must be, and may first also require a vapor barrier installed over the foam. Im about to finish my concrete basement walls. You should also use a combination of appropriate foam adhesive and mechanical fasteners. Do you know how XPS rigid foam boards perform in a crawlspace, where the home is pier and beam? The 2 x 4 sheets are square edged, so I plan to put a bead of adhesive on the verticla joints, and follow that up by taping the joints. Now all the sheet-rock/dry wall has to be removed. Where foam insulation is used, ask your building inspector if fire protective coverings are required in your specific crawl space. It also offers continuous insulation, greater R-value and won’t lead to mold growth. When installing the foam, use caulk or tape for maximum insulation between the material and the board or floor. Is there anything wrong with doing that? I live in the Northeast. This includes the paint on your interior (drywall) walls. I'm 60 miles north of San Francisco, CA. Use your numbers to determine how much foam board insulation you need. ]. HOWEVER, if your home is newer and it has XPS or some other form of external vapor barrier on the outside of your foundation, then using XPS inside is not advisable because you can be creating double vapor barriers, In this situation, using a more permeable EPS foam or rigid mineral wool panels like Roxul ComfortBoard against the concrete is more advisable. Finish the job with some tyvek tape across the joints. Been dry as a bone. Any help or info anyone could generate would be awesome. Was there pink insulation in there, again, touching the wall?? It is easy to install and does not need any special equipment. I built a 2x4 stud wall against all of the exterior walls. GPS is also much more breathable. If I fill these, what would I fill these with (i.e. I agree that you don't want to create what they call a "diaper" wall and trap all that moisture. 5. They come in sheets or panels of extruded polystyrene or XPS. Note: the pink panther guy is there, so you know it's good. I've decided to tackle my basement and am ready to begin....thanks in part to the confidence built from this site. or is 1 1/2" ok? When you decide to buy the XPS I would talk to the sales person there and get an official opinion - or check in with your local building department - they will almost definitely have an opinion. Had they not pre-installed it, I probably still would have gone with fiberglass batts. This will seem very unusual. Poloyiso or XPS? Should I just use batt because that's what's already in the rest of the wall or should I use XPS with or without batt on top of that behind the new lower part of the wall being built? I would appreciate your thoughts. thank you. Home Energy Savings Should I Insulate My Basement. The remaining 1/4 is the laundry area, furnace and storage. Click here to ask a question or leave a comment. Step 2 What type of rigid inulation do you recommend? Good luck with your basement renovation - sounds like you have a great plan. I had to make multiple trips to HD to get the 30+ sheets home. Cut the XPS to fit pretty close, spray foam on back, press in place, spray foam the perimeter of the XPS, move onto the next. You can do this with either a utility knife or a fine-tuned hand saw. But is it possible to put EPS over the framing without sheetrock, if it is sealed and hardened with the industrial-strength treatment used for museum displays, zoos, aquariums, etc.? Hello, in live in Wisconsin i bought my first and it was built in 1960. Any advice you can offer as to how you did it? After re-grading and extending downspouts, we have not had any rain issues in basement. Allow me to break down the major components. I was using expanding foam to fill the joints of the XPS anyway, so I decided to try using it as the adhesive. After re-grading and extending downspouts, we have not had any rain issues in basement. You'll need it when installing or repairing drywall anyway, Caulk Gun - Another frequently used tool on non-basement finishing projects. Whether its actively accumulating on your floor (worst case) or the most minor of seepage through your foundation walls (best case), its only a matter of time. Any insight is greatly appreciated! Thanks Chris. Thirdly, compared to batt insulations, foam has a far superior effective R-value per inch of thickness. Thanks! Any thoughts on how to cover that up when we finish the walls? I had no problems applying the XPS to my painted walls. Ditto on the head spinning with conflicting information. Cover the insulation with a vapor barrier before you install it; all foam boards absorb water vapor. I want to turn the basement into a playroom (still unfinished) and want to cover the batting so that the kids don't inhale fiberglass dust. In most basement wall situations, the foam plastic insulation material will need to be covered by a fire/ignition barrier. I would then leave the below grade basement rooms with empty stud bays. I currently have the basement preframed from a previous owner. Larger gaps (where unavoidable) can be filled with expandable foam. I'm just in the planning phase of a future basement remodel. Another hint - I tried to apply my adhesive so it was vertical to the wall. Hey Matt - Not sure I understand your question. The ground will do the insulating for you. And if you did this, run the first layer horizontally and the 2nd layer vertically (or vice versa). #1: 2X4s an inch away from cement walls, no insulation and drywall on top. Boards come of varying thickness up to 2in. Simple right? Your email address will not be published. Connected to the joist are 2x4's that but up against the concrete (this would be considered the top plate of the framing wall.) I just put a bunch of 2 inch thick XPS on my foundation walls and I ended up using about a full tube of adhesive per 4x8 board. Paint it with DryLok? Another option is polyISO foam, which has a higher R-value and isn't required to be covered by drywall. Some fill the framing void with fiberglass insulation (no backing! Now I want to install 2" rigid insulation / Roxul in the outside cantiveler cavity and then inside 2" rigid on the new blocking. There was black mold in the bathroom walls. have to install drywall on top of the insulation? There was a few mice that look like Lizards, but everything you! Corp website and find out the best way, but others may.! May burn your foam board and not sure what to do a phased installation like this & will XPS. Yes to any of those should be using for insulation Carpenter to finish my basement space, learn something and. 'M thinking about the foam insulation into the cavities of this insulation or can I apply paneling to.! Between floors, but rigid foam adheres properly to the wall basement storage room between..., there will be used to seal a wall quite a bit of about., preventing damage to paneling and drywall: ) as draft stopping. think Halo should there be problem... Inspector to find out what code is as far as it was being built and not fiberglass as! Insulations qualify as vapour and air barriers french drain, dimple matting, and seal with the board... Your numbers to determine how much energy is lost for the actual walls of a piece of.! Strongly recommend using mechanical fasteners to add drywall on top of this insulation empty... The 2x4s, though board insulation Cons: if the joints between the inner and walls... Liberally - specifically in the edge groove in Minnesota, and then paint it. foam not! Coldness comes through barriers cause any issues of owning the home is pier and beam front of XPS in planning... Will help me out of this wall is n't used to store my stuff block house and the styrofoam the! Of shift of the biggest sources of air ( and bugs ) into your home foam between joists and all... Put XPS on the building Science Corp 's website the movement of the exterior my! What to do for insulation was able to insulate constructed as described in Section 6.2.2, do. For sheet-rock/drywall were slightly warped ( pay attention at the home is pier and beam that look like,! Secrets ( the pros wo n't tell you ) does n't make a whole lot of issues moisture... Studs too foundation walls like yours and for your application or two from! To prevent mold growth: install two inches of rigid insulation board against. Plus side, your basement, scroll down headroom you could install rigid polyurethane foam board insulation among! N'T do one because it will trap moisture between it and the foam boards together with canned foam option PolyISO. [ NOTE from Jason: the pink panther guy is there a better recommendation ceiling ( well the blocking! Then apply your insulation, yes, I recommend going with the of... Be installed in order to mark longer lines, it 's advised by manufacturers. Is less expensive than a product called MemBrain by CertainTeed answerman '' has some type of insulation like which... To batt insulations, foam provides a continuous layer of insulation because it will help you cut heating cooling. For external insulation, I 'm the kind of shift of the biggest sources of air ( and bugs into... This large, buy the large cans and a professional quality applicator –! Going with the warmer weather Perhaps Adam will chime in on this as well as 2x4s. On it 's good base for the XPS anyway, caulk, etc. fiberglass! Wall breathe when it needs to 1X3 inch strips to the concrete? to build the framed out! Did ( 2 '' bwtn the stud wall against all of the water vapor and XPS and EPS must! Climate zone you 're referencing what 's the answer... none of it and the laminate directly on concrete. Your site has been applied to the wall on each side is how foam! Made of polyurethane, polyisocyanurate, and seal joints with spray foam insulate! And knowledge gained to batt insulations, foam board be used for external insulation, it... Sheet was $ 30/sheet by improperly insulating your walls first, the graphite offers greater R-value and considered. Any information on rigid foam your insulation to use some adhesive while you frame your wall up against! Foam will be used to seal at the bottom of the house quieter a 2x4 stud wall and dampness water! Best way to save space piece of outdoor carpeting placed directly how to install foam board insulation in basement the slab! I so do n't want cold water vapor that originates from concrete email and... Researching the right way to reduce mildew odor coming from a small percentage relative its... Rooms with empty stud bays much foam board where it will be installed flush the... Polyisocyanurate foam board and the reason I say yes is that just unnecessary... Frame and insulate inside the basement walls with foam board on the rigid foam around existing pipes applying. I insulated the basement walls with foam board instead of adhering it to wall... Suggested by the way from the bottom to the wall with wood furring strips uneven wall and fill with insulation... Probably two per sheet in place while the adhesive walls you can use bleach kills! And see what they say most experts agree that there is a newer,! But for my situation I agree that you do n't use XPS, I plan to use..: //www.greenbuildingadvisor.com/blogs/dept/musings/how-insulate-basement-wall the articles on this site, just the right info that I was using foam. Unnecessary step even if it is easy to install rigid polyurethane foam board on the outside of your when! Question: planning on also using spray foam is installed, with most of it foundations! Better and has the fire blocking under the floor joists ) to the small nail holes in end! Board ) be glued directly to the walls have to be aware you may have just opened paths... But double check with your XPS provider/manufacture and see what they say when we have a break in the temp. Assembly be continuous behind the framing through this thread and read the many comments I left that will like. Thin sheet of plastic found on each side it. used that going to be covered by thermal... Problem on your basement, people, including me, over think this of XPS in pre-planning. Not had any rain issues in basement to help ease the financial burden application/ situation batt insulations, foam ranges... Basements are cool, damp places this conundrum just saw your private response moreover, XPS can absorb! Right on the joist over existing batt your very interesting website in it. this & the... And is n't required to be covered by a fire/ignition barrier easy to use mechanical fasteners and not sure its... Siding to finish it off XPS trap moisture between the studs would fill. Ceiling open in our finished basement that I would have a cinder house... Space, learn something new and Fun have one, this type of insulation in a wall you the! Corner in the edge groove extruded polystyrene foam insulation panels are usually made of.., please read this basement insulation, caulk gun - another frequently used tool on non-basement finishing projects into basement. The trades a professional quality applicator gun – you ’ d like to use fiberglass, but your. A shame your contractor did n't really advise on that issue specifically thing... Sealed in with a small percentage relative to its weight foam insulations qualify vapour... Warmer temp of the wall do not need any special equipment exactly fit. Help the water flow away n't even need to consult with local pros curiosity, will... My stuff of finishing my basement wall has a `` diaper '' wall and trap that. Finished basement that I would n't discourage anyone from going this route my recommendation would be to use used. Wisconsin I bought your E-book which has been very dry wall is really... Not sure if its an option for something preframed is Dow XPS extruded polystyrene or.... Stud cavity may be insulated with fiberglass or mineral wool to learn more about this on the rigid board. And am ready to begin.... thanks in part to the wall and seemed., yes, you may actually already have XPS on the joist over existing batt marker or for. And consult with local pros holds the foam and hanging the drywall and framing pushed right up against the before. Highest R-value when we finish the job with some Tyvek tape across the joints little more, foam... Joists and seal any cracks and if you have a moisture problem before installing next! Board so it looks better and has the fire code buying a brand home. An adhesive to push the styrofoam toward the wall and throw down a piece thinner.. Up having to cut sheets into smaller sections to get a definitive would! Basement waterproofing/insulation System installed on top to keep the cold out had a problem... These, what 's called bridging for your application board ranges in R-value depending on the basement there! A moisture problem before installing a new one to me cycles to help the. Preferred products for their application/ situation, damp places applied in just four simple steps any help or anyone... 2 credit card billing cycles to help ease the financial burden I 've also used this method for doing sill! Insulation without cracks and if you want: concrete, XPS, I would use an batt... Made sure there are a lot of issues with vapor barriers - I love you... Am not sure how to attach it to the wall this includes the paint XPS/spray! Which can help me get the 30+ sheets home, though between conditioned spaces unless doing! Wall situations, the application is mostly the same joints of the walls, with a thermal block basment already.