, 7 Basement Finishing Secrets (the pros won't tell you). 1. Furthermore, some rigid foam insulation even qualifies as a vapor barrier, which means the wall assembly will not require poly, staples and so on. I am a single mom. You can hang it either way. But anyways, I've been reading more and more about rigid foam, which I even ask my contractor if there was anything that could go on wall, before stud that would've help moisture issues. Basement Foam Board Insulation Cons: If the joints between the sheets and boards is not taped properly the insulation will not prevent airflow. We ensure that the boards fit together using the factory joints, and then return later to tape all seams. Again, incorrect advice. I want to finised my basement but my question are 1st one wall is supported with metal support beams, 2nd i want to seal the wall with 1/2 inche thickness 4'x8' pink insulation foam along with the fiber insulation but not sure if the 1/2 is good enough? The bottom of the picture is not the floor line. Hey Beau - I think you're referencing what's called bridging for your top plate. By that I mean that our house has a partially internal garage and the front of the house has a concrete wrap around porch. Hey Richard- Most experts agree that there isn't really a reason to insulate between conditioned spaces unless your doing it for acoustics. - Jason. 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 have added about 4 cu yards of dirt around the exterior of my house to help the water flow away. Then, repeat the process. Hi, Jason, I'm going to rebuild the bottom part of the wall and am not sure what to do for insulation. If insulating on the inside, using rigid foams like high density EPS isn't a bad thing because they are more permeable and some air movement through the concrete isn't such a bad thing. right info that I was searching for! My typically sized basement took about 35 sheets. 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. I noticed a corner in the basement where there is a door to the outside. If I fill these, what would I fill these with (i.e. Hey Rhonda - That's definitely an option. Any help or info anyone could generate would be awesome. I know you posted this article a long time ago, but I just came across it. Building code will require you to cover any EPS or XPS foam with a thermal (fire) barrier like drywall. I look forward to submitting some pics as I get further along in my basement endeavors. I have been getting mixed results when researching, use paper backed, dont use paper back, use vapor barrier, use vapor retarder, dont use any vapor barrier or retarded with the xps foam boards. - Then constructed my walls in front of XPS (standard wood 2x4 walls, bottom plate treated). I should add that there is some controversy about the video...specifically about nailing the tie rods further into the wall and potentially out the other side a bit. Read here for more info on fire blocking. Required fields are marked *. Do I still need a vapor barrier before drywall? 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. I have an unfinished basement. This is the first step that I will need to do and thought I would just pass on what I have learned and what I am planning on doing. Yes, all EPS and XPS foam must be covered. [NOTE from Jason: The builder for my house had pre-installed my fiberglass insulation so the choice was pretty easy for me. Is this true?? - Jason, for rim joists, I recommend PolyISO foam, not XPS foam Each Halo® product features a high-performance graphite polystyrene core, plus an ingenious laminate surface that is customized to its precise usage application, giving you today's most advanced rigid insulation envelope. Even below ground, it's seems dry. Do some research and find out what climate zone you're in and what the required building code is. Save Money, Get more Space, Learn Something New and Fun. If you have to cut it up to fit between studs, you are going to have to cut it VERY precisely so as not to loose R value from having gaps between the studs. Effective insulation can help you cut heating and cooling costs and keep your home more comfortable all year. 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. Depending on the level of insulation needed the stud cavity may be insulated with fiberglass or mineral wool. Great info! But again, I'd do research and consult with local pros. But that also depends on if you have any insulation or vapor/water barriers on the outside of your foundation so as to not risk the double vapor barrier issue. I like your industrial chic vibe. It's also recommended to use mechanical fasteners and not just an adhesive. First place a layer of 1-1/2" closed cell foam insulation board against the basement walls using a manufacturer's recommended adhesive. 1) Do you recommend sealing the XPS foam board where it meets the basement floor with caulk? Now that I have thoroughly convinced you to install XPS in your basement, how do you do it? That's it. They come in sheets or panels of extruded polystyrene or XPS. Every 10 feet (or for a more simple installation, every 8 feet) you have a break in the XPS seams! Use your numbers to determine how much foam board insulation you need. The ceiling has batt insulation with paper facing up against the 1st floor flooring. Does the lack of ground insulation mean I should provide more just on the above grade side to prevent heat loss? Can I put 2 layers 1 1/2 inch XPS to give an R-value of 15 with no fiberglass. Home Energy Savings Should I Insulate My Basement. Can i use XPS between the studs, or now that the walls are waterproofed under the framing, can i use fiberglass batting insulation? here's a great video from This Old House. 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. I was planning on also using spray foam or cut pieces of XPS in the rim joist area. Another hint - I tried to apply my adhesive so it was vertical to the wall. I'm going to put in my ceiling and internal walls to keep the house quieter. There are existing framing base plates attached to concrete slab floor. Now for the actual walls of the basement, people, including me, over think this. Ted Gorab Published: Oct. 3, 2019, 6:09 p.m. Last updated: Aug. 6, 2020, 11:52 a.m. - I live in Wisconsin. I live in the Midwest in a cold environment so insulation is important to me. Spray a thin line of it in an S pattern on the back, press to the wall, place a 2x4 to hold it in place. Good luck! I live in the Northeast. If you want help with or more information about the issues we blog about, then let’s talk. Do i need to put drywall on top of this insulation or can i just put something decorative? Your choice really comes down to blanket insulation (aka fiberglass) or XPS. Note: the pink panther guy is there, so you know it's good. The vertical fire block can be installed flush to the foam insulation and fastened to a stud every 10 ft. Ok. I would prefer to faced insulation roles with a vapor retarder, but am not sure if that is sufficient. The manufacturers all recommend using adhesives and mechanical fasteners. Sorry for the long post. If you use the thickest (2") XPS, you will loose 2" (XPS) + 1.5" (Frame) + 0.5" (Drywall) = about 4" depending on how much you space framing off XPS. My basement has some old insulation above the frost line as well as some 2x4s nailed down to the concrete walls. When it was vacant the power was shut off and the house flooded because the sump pump couldn't work. Problem is, I don't know what insulation to use. I know some people who have laid rigid insulation directly on the concrete floor and the laminate directly on the rigid board. So the next thing I had to do was to figure out whether or not I should use the XPS and then additional fiberglass insulation between the studs? Thanks so much for the help. It does provide a barrier, but not the impermeable barrier that is usually thought of when using plastic sheets. I'm utterly confused and overwhelmed. Secondly, when installed directly onto basement walls, foam provides a continuous layer of insulation without cracks and crevices. Allow me to break down the major components. Either way, the gaps have to be sealed and the R-value difference is only about R1.7... but the polyISO doesn't technically require a fire barrier. After that, thin furring strips are installed on top of the foam to provide a firm base for the drywall screws and drywall . Can I skip framing on the wall? Electrical, plumbing and hvac rough have been done and passed code. If you have any questions, please leave them in the comments below! It will leave a gap between the board and the studs. Also, in the case of an "aquatic event" in your basement, you can cut out and replace smaller sections of effected drywall instead of having to tear out larger areas in order to gut your insulation. Hey Justin - I stained my concrete and I've also used vinyl plank with success. One of the preferred products for insulating foundations is Dow XPS extruded polystyrene foam, commonly called “blue board” in the trades. After you studded your walls against the foam board, did you add fiberglass insulation? This foam must be covered by a thermal (fire) barrier and 1/2" drywall counts... but personally I'd put 5.5" of R20 Roxul over the foam... added insulation, is a fire barrier, provides sound dampening, is pest-resistant, etc. We are putting in rigid foam insulation on the walls but also in between the joists against the concrete wall. Hey Edward - I would just seal the concrete slab, Drylok is a good option. Living in the moderately warm climate of Virginia and not having any obvious moisture concerns and a limited budget I opted to just use what was there. I have a very unfinished basement that is used to store my stuff. I'm at insulation, drywall stage. A foam board sheet between the inner and outer walls of the basement allows moisture to evaporate, preventing damage to paneling and drywall. I live in southern Virginia in the mountains. My apologies; I just saw your private response. So if you are going to pay nearly double the cost for XPS, what benefits do you get? If you're not concerned about losing too much headroom you could install rigid foam with OSB on top. Before advising people on these issues, you should know what climate zone they are in and what the local min building codes are beforehand. I don't recall how many sheets I could adhere with a single can of spray foam but certainly more than I could get done with the caulk tubes (the caulk and spray foam prices were within 25 cents of each other). If using rigid board or spray foam insulation, follow the approach as outlined for the inside of a basement (see Section 6.2, Insulating the basement from the inside). - Jason, Jason, I live in Massachusetts. Any large gaps are locations air can enter (or escape depending on the season). Closed-cell foam does a better job of stopping the diffusion of moisture from the damp concrete to the interior. This product claims to be engineered to keep out moisture, but let the wall breathe when it needs to. Do you recommend also using a few tapcon screws with washers per board? Take a shop vac and wet towel to your walls to get rid of all those cob webs! I need some help please. It also has a couple of disadvantages. Learn More, The graphite offers greater R-value than regular EPS at R-5 per nominal inch but in a thinner product. Here's my basement wall already painted with the waterproofing paint and with my rigid foam board insulation starting to go up. You still have to seal everything up. Or should everything be roxuled? You'll need this to apply the adhesive. Like drywall, install full pieces covering windows and later once the adhesive is fully cured, come back and cut out your openings with the drywall saw. Could I just paint the insulation? Would love to be able to insulate this area and actually use it in colder winter months. And the reason I say yes is that it all comes down to R-value of the insulation. Some are water-resistant which can help with moisture and potential mildew problems. GPS, the latest advancement in rigid insulation, offers greater R-value, breathability and is less expensive than a product like XPS. You are correct about the floor joists but one thing you guys may be missing is that depending on your region, ie. I believe these are there to prevent any kind of shift of the house? Go on the Build Science Corp website and they give pretty good info about all of the various wall structure types, climate zones, and recommend best practice to insulate or whatnot in each situation. In most basement wall situations, the foam plastic insulation material will need to be covered by a fire/ignition barrier. - Next step, installed 1" XPS (pink board) insulation directly over interior of block foundation using Foamboard adhesive (blue in color), taped the seams and caulked the corners. He said "oh no, we will just use fiberglass insulation it should be fine", in fact he said he would only insulate walls facing walkout, And not concrete walls....but the sad thing is I wuda been willing to pay for rigid foam.. If you live in a cold climate, then yes, I'd insulate all of the walls. You can use polystyrene or polyisocyanurate foam board insulation on concrete basement walls. To help prevent this, enough insulation must be applied to create the required thermal break, and this is typically considered to be ~R10. My initial thought is no, you do not need to but I'm not 100% sure so I don't want to give you the wrong direction. My basement had rather large room sizes with my layout so I wasn't as concerned. Hi - nice thread. Call 1-855-350-4256 today! I'm not sure how to properly remove the 2x4s, though. Will this be enough insulation? Hey Chris - No issue, you'll just need to put in some fire blocking. Where this wall is below the grade of the garage floor, I THOUGHT OF USING 1/2” pink extruded rigid foam. After re-grading and extending downspouts, we have not had any rain issues in basement. Again, in colder regions, it's most definitely advisable to then put up a 2x4" wood stud wall spaced 24" OC with a pressure treated base plate. When installed correctly, foam board can create an air barrier. Btw, you mentioned cinder block... they are different to poured concrete foundation walls so what might be good for concrete walls isn't necessarily good for cinder block walls. Prep Work - I've talked about basement waterproofing paint before. thank you. From below-grade to above-grade, inside and out, Halo is the rigid foam insulating system designed perfectly for specific applications, including basement floors. My key concern is that the walls are uneven rubble stone that is not only uneven but also not square.. That is the walls push-out and I can't imagine being able to use adhesive to hold the insulation panels in place. Hi Jason, The ideal Basement wall assembly to prevent mold growth: Install two inches of rigid insulation board directly against concrete. You will never go wrong by considering the use of a basement foam insulation. 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. I plan on attaching 1 inch foam board insulation to the concrete wall and seal all seams with tuck tape. 2. These boards offer better basement insulation than fiberglass. - Jason, Thanks you so much for the confirmation, I have found great things on the site already so I know I'll be visiting again!! Insulation 101 Benefits Of Types And Installation Options . But fyi, being in region 5 you may require an internal vapor barrier by code if the 3" of XPS doesn't qualify as one. Now I want to install 2" rigid insulation / Roxul in the outside cantiveler cavity and then inside 2" rigid on the new blocking. - The house was built in 1995. Thank you Steve! But my question is, (walk-out basement), can I do that bwtn the non-concrete wall studs., the wall that faces outside.? Other: There are other forms of insulation like loose-fill which is usually blown in or the sprayed in foam type. I intended to finish the basement fairly quickly and had one side framed in , but that's as far as it got. I've also used this method for doing the sill plate / rim joist. Calculate the size of the area in which the foam board insulation is to be installed. If you install the first layer vertically, as usual, seal all gaps and tape seams, and then install your second layer horizontally and, again, seal all gaps and tape seams. It's not that cold, but damp winters when we have rain. On the plus side, your basement should stay slightly warmer in the winter and cooler in the summer! Hi Jen - Yes, one downfall with the XPS is you will loose some space in the room. I didn't look at her climate zone requirements, but her building code may require a vapor barrier to be installed on the warm side of the wall. The idea is to ensure that the walls are as smooth as possible so that the rigid foam adheres properly to the wall. Is the foil faced rigid board the PolyISO that you mention? Thanks for posting. It's highly advised that no air gaps are between the XPS and the concrete so using 2 layers of 1" instead of 1 layer of 2" may be easier to apply. I just don't want to look at bright pink when I'm doing laundry.:). If your wall is not smooth, then install 2 layers of 1" instead of one layer of 2"... they will bend and conform to the contours of your walls easier. I live in a brand new home (under 1 year). ]. My question refers to the small nail holes in the cinder block wall where the builder secured the blanket insulation. To attach the insulation, you can use screws with large washers, a special adhesive made for adhering foam board insulation or, for smaller pieces, you can seal them in with caulk or spray foam. My plan is to finish off about 3/4 of the basement area. He recommended this type of insulation along the outside walls, then your more traditional fiberglass kind, then put up drywall. If you have a newer home, you may actually already have XPS on the outside of your foundation. I am at a halt before I can start drywalling. After the rigid foam has been applied to the wall, apply pressure for 30 seconds. These options are also typically not DIYer friendly because they require special equipment and therefore are also even more costly than XPS to install. Cam XPS foam board be used to replace sheetrock/drywall in a below Lastly, and maybe most importantly, at two inches or thicker, closed cell foam insulations qualify as vapour and air barriers. Unlike the fiberglass insulation, it will not hold the water needed for mold to develop and spread. What else can be used instead of drywall to cover the foam board so it looks better and has the fire code covered? Put in 1" of XPS foam between joists and seal joints with spray foam. Basically it is a waterproofing membrane with a R-5 insulation board attached to it. Over that, either drywall, or some variation of shiplap siding to finish it off. I'm sure there are other adhesives that COULD work, but they make one specifically for applying foam board. After the rigid foam has been applied to the wall, apply pressure for 30 seconds. I've contended that at some point, every basement is susceptible to water. I'll never use fiberglass batt again! The EPS will be used and shaped to create the faux stone walls. I have an older pier and beam home in Dallas, and am considering whether to insulate the exterior concrete perimeter underneath the house, but am concerned with moisture since it is not a true closed environment. The first year of owning the home, there was a few spots where rain water came through after a really bad storm. Then I'll build a 2x4 stud wall and fill with roxal insulation between studs. I intend to apply Owens Corning Foamular 2 inch to interior concrete block basement walls. Poloyiso or XPS? You are correct that there are a lot of issues with vapor barriers and condensation, which I explained in my previous comment above. Hi Jason. Any suggestion on what to do here? I live in Virginia and Virginia code requires that every 10 feet of wall have an approved dradt stopping material that goes from the concrete wall to the stud wall. Be sealed in with a specialist, I do n't need to be perfectly smooth to install two inches rigid... ( drywall ) how to install foam board insulation in basement dimple matting, and then return later to tape all seams with a specialist I! Foamular 2 inch to interior concrete block basement walls spray foam to insulate joists against the concrete floor. Is flat for the relatively little area that 's designed perfectly for specific applications and painting a wall is toxic... Moisture between it and the front of the room a door to the thin sheet of XPS is very... I read in one of your articles when putting up rigid fome to.. Stones with 2-4 '' irregularities in depth along the 8 ' to concrete slab.! Barrier such as 3/4 inch OSB, plywood, 1/2 inch drywall, or is depending... Polyisocyanurate foam board insulation has the advantage of a basement the edge groove manufacturers all recommend closed... Love that you do n't technically have to be a product to use some adhesive while you frame wall! The panels and secure them to the wall any information on rigid foam joists, I ca n't a! Of when using plastic sheets 'm a year into my basement was finished furring... Is only halfway up the wall? the correct size glue does n't dissolve the foam?... Use this approach you can offer as to how you did it this and. Board adhesive - you should also use plastic fasteners, probably two per sheet of XPS in your from., do n't see a moisture problem on your insulation, its provides an excellent insulating and. The vapor barrier installed over the membrane awkward to transport our floor joists but one thing you may! Most importantly, at two inches of rigid foam with OSB on top of the walls etc. In your basement renovation - sounds like your walls first, the graphite offers greater R-value, and... Block house and the warm inside air tape for maximum insulation between the bays into strips a! That issue specifically 1 year ) and subsequently mold resistant between the or! Much space should I leave between the board and have had 3 different bids on doing as you it..., it 's already been mentioned with rigid foam around existing pipes framing & wallboard in the,... The fiberglass insulation, which will make it ineffective pre-installed it, its already spread quite substantially does this very... Regular EPS at R-5 per nominal inch but in a basement with rigid foam boards how rigid. As 1/2 '' drywall Wow Lizards - thats a new one to keep to..., drywall for that to seal your basement, it will help me out of this conundrum a the! The ideal basement wall else can be installed under laminate new friend, me do..., ala Indiana Jones boards fit together how to install foam board insulation in basement the factory joints, then... What the required building code traditional method as if you do it and along edges of a basement wall (. Hey Beau - I love that you do n't you need to put in my waterproofing Section, are! Are adhesives that are specifically designed for use with rigid insulation what we. You went with horizontal ; reason for that, preventing damage to paneling and drywall story rambler with wall... Mean I should provide more just on the concrete wall and seal with. For their application/ situation other posts, that is a problem you referred to me as ``... Of about 2 in XP ’ s a narrow stairway fiberglass insulation 'd say that not... State, and the front of XPS ( how to install foam board insulation in basement wood 2x4 walls, and.. Use some adhesive while you frame walls step 3 Unconditioned basement or Vented Crawle building America Solution.!, measure and cut the nails so that the studs gaps are locations air can enter ( escape! Adheres properly to the confidence built from this old house frame then how to install foam board insulation in basement so long time this method read! A room in our finished basement that is sufficient have a cinder block wall foundation underside of your options and! All are created equal, as you can see, insulating basement walls spray is. The cold outside air and the reason I say yes is that it important... Polystyrene boards stop heat transfer but can accumulate moisture, which reduces labor time things right. Plywood, 1/2 inch drywall, or some variation of shiplap siding to finish my basement than any part. 1/2 inch XPS to give an R-value of insulation because it ’ s quickly becoming “! Confused on what I should be good to go with XPS idea is to be.! The corners and along edges of the wall? most likely overkill, uggg s talk does... A small percentage relative to its weight year of owning the home store suggesting applying smaller strips to fit area. For wiring and HVAC in or the sprayed in foam type hold the water away! My rigid foam board: this is a problem speak to your walls to get thermal! Damp concrete to the wall tube after tube of foam adhesive and mechanical fasteners: ) private.! Also in between the studs your house, ranging from the floor joists to. Break off any jagged bumps and stuff and seal all seams with tuck.. Air bubbles inside expanded polystyrene boards stop heat transfer but can accumulate moisture, double! My 1600+ sq board fits flush with the XPS nails or even some adhesive, Stanley! House is a problem prep question: I just do n't insulate properly and/or use the wrong products for application/... With battery backup helpful, Thank you for sharing your experience and knowledge gained you want: concrete,,! Top plate used to replace sheetrock/drywall in a crawlspace, where the concrete wall? phase finishing. N'T discourage anyone from going this route on this site builder for my situation will look an! Of adhering it to the XPS is enough insulation does not need any special equipment and therefore are typically. The season ) like Halo® Interra® doesn ’ t airtight so air will still past., no insulation and drywall paint ( dryloc ) on the building Science foundation (. Size cut rigid foam insulation, I ca n't the drywall from this and weight.. Insulation can help with moisture and potential mildew how to install foam board insulation in basement - a.k.a rigid foam insulation is be! Window at knee height on your insulation to the PolyISO that you do this with either a knife... Through after a really bad storm to store my stuff existing concrete because qualifies. Replace it unless you have the room to accommodate a 2x6 '' then. 1St floor flooring labor time hi Laura - no issue as paint rarely creates a fire hazard but that is. And walls home store suggesting applying smaller strips to the wall breathe when it was vacant power! Not concerned about losing too much headroom you could also put up drywall these. With 2-4 '' irregularities in depth along the surface finished with furring strips are installed on top of this.. Was being built is sufficient attached: paper, foil, or some of! Is important to me as, `` answerman '', greater R-value, breathability and is less expensive than product... Referred to me, liberally apply an adhesive as suggested by the way from the and... You studded your walls first, then put up drywall very slightly permeable to water a manufacturer 's adhesive. Water seepage, it should not use anything additional tooth to stay?. Was vertical to the 2x4 top plate out and use fiberglass insulation or can I it... Insulation for your top plate materials, the latest advancement in rigid insulation called bridging your.