Will heat with portable electric heat if need be. The exterior consists of vynil siding and Tvec. Good luck. It is damp in basement but no water problems.There are mildew problems, especially in summer. The walls are already sealed and has no noticeable moisture issues. The Foam can go over the Tyvek and will definitely make a difference. I likely will get the ceiling closed cell spray foamed but likely not spray foam the walls two story, plus a drive under garage is a lot of walls but not much roof. I started building a room in the basement. I believe all walls are 2 bricks thick and the outside is painted brick. I caulked and sealed the seams with tape. ), then sandwich the foam between the next hat channel and screw them together? Would it be better to use xps against the wall and use the eps (rather than fiberglass) for insulating between the studs? The builder wants to use 1.5 inch XPS, sealed at all the seams, I will push for 2 inches. Do you have access to both sides of the wall? All Rights Reserved. This house is 5 yrs old and basement has never shown water leakage. Closed cell spray foam – works wonderfully, definitely most expensive option. i have been told that I may not want to use the foam on the ceiling or rafters of a similar room due to condensation would build up between the drywall and foam and cause problems? 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. I do not want to remove the attic floor to insulate. I don’t have the specs handy but you could check online to see what the flame spread rating for foil faced is. When properly covered from the sun and environment it should last indefinitely. Typically crawl spaces benefit nicely from foil faced polyiso foam board. And in either case what is the best to use for a vapor barrier and where?? Todd just had a contractor stop by and give me a quote on the closed cell spray insulation. Here’s a real quick thought of mine on these sealers (also let me say that my Master Degree research was on concrete material science so I know a bit about concrete). POLY SHIELD® is made of Cellofoam Expanded Polystyrene (EPS) rigid insulation… Thank you Todd for the quick and informative answer. Also, do the outlet boxes need to be filled around with foam air tight? Good luck. I intended making the transition from below grade to above grade (the south facing walls/windows will be exposed to maximize passive solar heating) by staying with exterior insulation and going with a natural or manufactured stone veneer. The exterior has 1″ XPS covered with vinyl siding. Should I still fill cavity in between studs with R-13 fiberglass insulation? Thanks. ICF does have some minor issues that need to be considered. Type IV properties require, among other things, a minimum R-value of 5.0 per inch of thickness. It seems amazing the difference insulation can make in a concrete condo. I also need to cover some voids created by dropped ceilings over the kitchen cabinets (unless it’s ok to simply fill them with the blow-in). All of the joints in the foam should be sealed well. Only issue is that the new sheets obviously look newer than the 13 year old panels that were previously installed. They include expanded polystyrene, extruded polystyrene,  and polyisocyanurate unfaced or foil faced. Hello I would like to insulate my garage door Iam in central Florida which would be better Polystyrene or Polyisoc. The boxes will be bolted down to compress the seal. DOW products has lots of information on their site about different foam board products here. I am planning to insulate a large basement, over 200 ft of outside block wall. Secondly I would insulate that wall, you are correct, 2″ of closed cell foam (XPS). You may want to consider insulating it with just foam board to really eliminate the problem all together. Also, we plan on keeping left over paint etc in a part of the area and don’t want it to freeze in winters. Most codes require a 20 minute thermal barrier such as 1/2″ drywall. 3. thanks for the help, Ryan. Thanks for any info. I’ll warn you, foil faced foam really should not be in direct contact with masonry, I would use XPS foam. Todd, I am insulating my Seattle basement . Spray foam tops the list, polyiso would be next. I’m having a contractor finish my basement and he’s recommending 1″ foam board adhered to the concrete walls with no further insulation. This is one of the only forums where there is no “agenda” to sell a specific item – and that is great. Do you have a vapor barrier on the exterior wall over the batt insulation? You’ll want a really good vapor barrier on warm side. Can I glue the foam board right to the concrete? The stud walls have been there since constructed and I see no signs of mold at all. 1. Some Box Stores rent insulation blowers which you might be able to use yourself. My question is, is this a good idea, what type of rigid board should I use? I was planning on making my own cover using extruded polystyrene but after looking at this article, I wondered if polyisocyanurate would be better. Can you put foam insulation in the garage ceiling over drywall to gain better heat? I have a all concrete room under my garage and I am planning on finishing this room. I’m curious how this project turned out. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. I do have a friend with a truck to get some 3-4″ here. Which one is less likely to absorb moisture? I'm full time builder for a large construction company in New Hampshire. ZOENHOU 20 Pack 11.8 x 4 x 0.8 Inch Foam Rectangle Board Sturdy White Insulation Board Firm Grain Foam Backing Mat Water Resistant Foam Sheet for Extra Packing Protection and DIY Crafting. Would like to add 2 inches of foil faced ISO on the bottom of the rafters, then blow in cellulose in the space above the ISO, below the baffle. If i sister some 2x10s as you suggest do they have to go all the way from the wall up to the ridge? I will only be able to put in about 5 inches of insulation and wanted to up the R value by adding 1″ of foam over the rafters then putting the drywall up. Or would spray foam be better? Todd; I hae just started the process of conerting an area of my unfinished basement into an office/den. 7/16″ OSB will warp, sag and look pretty horrible within a few years of installation. 5 – windows/ doors. My boss was thinking about making steel boxes and using foam board inside. This room will be used for storage mostly but may be a office one day. What would you do if it was your place and you were looking forward to that extreme of cold? I am wondering what your opinion is on the following. Joe – Using foam inside the cavities is a fine idea. How To Insulate Basement Walls Insulating a basement properly is rather challenging in cold climates. Also, I assume the top of the concrete (sill) will need to be insulated as well? Fan Fold Available in Halo Exterra and PolyPro. Except the area where the roof is highest, which I’d like to use for storage. The channel makes for a VERY good sound deadening detail. Am trying to locate a foam 1/2 inch or less to just give a bit of thermal buffer, but not loose much height. 2- How to fix the polyiso on the vapour barrier? (Google “Tumbleweed Cyprus” to get an idea.) runners that the metal siding is attached to. Christine – That method actually works quite well. Thanks Todd. He mentioned 1/2″ of closed cell and 3″ of open cell on top of that on the walls. That extra bit really makes a big difference in performance especially in climates with large temperature swings like here in the North East. I run a 110 cfm bath fam before and to 1/2 hour after after each shower. Tim – That approach will work just fine. Sheetrock may be cheaper, but it is a lot quicker and easier to just remove all the siding rather than try to get behind tubs and kitchen counters and, and, and….. :) I don’t want to double up due to the issue you mentioned regarding doors/windows. Most folks are building these in temperate areas – I’m looking to build one as a permanent residence in Vermont. A 3 or 4″ panel would probably have to be cut even smaller. I was asking if he had a vapor barrier on the inside of the exterior wall (i.e. Obviously, it’s a large task to get behind them. What would you advise me to do, and if I went with new insulation, what R value should I aim for? Rich – I suggested the foil faced as a bit of safety insurance. Want to save 10% on a major purchase at Lowe's? (we have to have 2×6 on large side walls). we have a 55 year old house, brick..our bedroom is in one corner of the house and the walls are FREEZING in cold weather (no insulation to speak of I guess)..is it possible to put a foam board (which one?) The Power of Embedded Polypropylene Studs. The problem is, the rafters are 2×6 and notched halfway leaving only enough room for the batt insulation that was in when house was built. Not sure tar paper is going do to much of anything for you in this situation. External applications should always use Closed Cell ISO. And should the foil be facing out? There will be a space from the new framed basement wall to the foam board. … Is it a row of brick, air space, sheathing, framing, plaster? BTW, when butting the sheets of ISO together, would you recommend an adhesive/sealant and then taping the joints? I’m looking to build a “tiny home” – roughly 8′ x 24′, or about 200 sq.ft. Can you give me any directions as to where to look? Mike. The notched edges make sure that alignment remains true, and the panel is able to bridge irregularities along surfaces while retaining an airtight state. Good luck. Bathrooms should not matter either. My thought is to use 2×2’s as nailers in between the roof trusses and add some 2″ rigid insulation between to make it flush with the bottom of the roof trusses. That really isn’t going to increase the R value. Why not use an insulated metal panel. You might want to add a layer of 7/16″ OSB then the wood which will likely make the rating pass. Concrete can transmit cold easily so if the entire wall isn’t insulated well it could still be an issue if the temps get really low. So I was curious what your thoughts were. I read through all these posts and didn’t find my exact situation, so thought I’d post. Can this be sealed? I’d try to avoid notching the foam. I live in Madison, WI and I am converting a screened-in porch into a room. Good luck. – One inch of foam board isn’t sufficient for two reasons. By screwing the furring strips through the blue board into the cement, does that not let in the moisture that seems to be the trouble with basements? As gas escapes, however, the R-value of polyiso can drop over time, but foil … Whereas XPS is a solid, closed cell foam product. Pat – You certainly could do that but you need to check on the fire rating of that assembly. Closed cell foam spray too expensive will open cell sprayfoam be ok? Fuel costs will only continue to rise as time goes on. The house is heated with forced hot air. I understand that it will certainly help with the temperature control in the rooms and I know it is recommended for that point alone but, is it against building codes to not install it as well prior to drywalling? http://www2.dupont.com/Tyvek_Weatherization/en_US/products/residential/resi_seam_tape.html, You can also use this stuff, it’s similar, http://www.amazon.com/exec/obidos/ASIN/B002KM1APU/homeconstimpr-20. Then backfilled with clean stone material with a complete perimeter drain to drain any ground water. I will install blue board between the studs then insulation over top. If I only did the finished portion, I was planning on insulating (w/vapor barrier)the interior dividing partitions between the finished and unfinished spaces. and claims that he has not had any condensation issues in his basements. With an R-value of 6.5 per inch, polyiso offers greater thermal resistance than other rigid foam products. I found that I could remove the existing 12″ standing seam sheet metal roofing without damaging it. External application of ISO must be protected from UV as UV radiation will cause it to break down. – Spray canned foam around seams to the wood rafters best? You’ll need to discuss this with your local building code official. Foam board insulation is easy to use and is a great DIY way to add some insulation. I plan to check that all the cavities are properly filled. Todd – I live in Colorado with a 1978 home. Most codes vary but they all need at least 20 mins (1/2″ drywall). You can certainly install another layer over the old after it’s inspected. If yes to both this approach will work well. I was thinking of pulling up the old “pink” insulation and laying down some polyisocyanurate board between my abnormally short joists. I went to Home Depot the other day to get an idea what types of foam insulation they carried. Mike – Have you cut a whole in the wall to see what the wall section looks like? Also, with your high humidity I’d be inclined to avoid the fiberglass. ICF is much harder to deal with electrical and plumbing (although certainly not impossible). I wouldn’t put the foam between studs because you won’t have any thermal break. So, moisture that forms on the inside of a housewrap will be trapped as effectively as the housewrap excludes water penetration from the outside. Possibly by stacking batts or rolls against it. Outside winter temps norm range from 1 to 8 degrees Celsius, summer 15 to 30. If anyone has been through this and found one (for a cold climate home) I'd love to hear how it turned out for them! Thanks. (The inspector somehow missed that.) The ceiling rafters will be furred out to 12.” And to allow for heating ducts, the floor is raised about 14′ on 2×8″ joists. However, your system will probably work fine. If we go with the first option, will the gap between the foam and drywall (separated by the furring strip) be a problem for moist air? The roof insulation will be an r-50 (typical blown in insulation). Hey Todd, im going to be siding my house this spring . Some types of thicker foam board insulation are available, but they may need to be special ordered. Of course, he also has the luxury of building from scratch, and he puts great emphasis on drainage rather than waterproofing, but his house was built in the mid 80s and is still dry. From reading other posts I think I should use 2 inch XPS foam sheets (or closed cell spray foam) directly against the concrete and then drywall with nothing else. The outside walls are a decorative type masonry block. He wonders if he’ll have to move the foundation wall out to accomodate another 2″ in addition to my planned 2×6 walls. Robert – Thanks for the kind compliments. I will install 2″ of rigid foam insulation under the slab. and FOAMULAR® rigid foam insulation. They will develop mold. The sun gets pretty hot and I was concerned if the insulation got to hot and dry day after day it might combust. Dylan, You’re MUCH better off blowing additional loose-fill fiberglass over your existing insulation. I live in Jacksonville, FL and due to age and water damage, I had to replace the bottom sill plate on my 1940’s garage apartment. One of the best resources for hot humid climates is: http://www.buildingscience.com/documents/profiles/etw-houston-profile. Plastic nails seem perfect but if you have other ideas, I am open! The air space is actually a good thing. How? As far as adhering the insulation, do you just use construction adhesive to install the foam boards, and if so, how do you hold them tight to the foundation wall? Any adice you could give would be appreciated. Also, in hot climate, it could reduce the life of shingles. What do you think? 1. and is getting in the wall somehow and cannot escape due to the vapor barrier. The wall are cement block. Any ideas on this? I’ve thought of using packing peanuts (good way to recycle them!) – You’ve in essence created a double vapor barrier that wants to trap water in the stud wall. You are creating a deeper void and something to attach drywall to. Part of the basement is above ground and was insulated with fiberglass. They pass water vapor both ways, and they trap water droplets on either side EXTREMELY well. In other words not worth the investment? Shouldn’t be a problem at all. also insulation in between my studs R15 I can use a non vapor backing if I foam board my foundation walls correct? Ryan – I would recommend using foil faced polyiso under the siding. So, we're looking at options to claw back some of the insulation lost to the siding while avoiding too much of a moisture or water vapor barrier. Do you have a ridge vent? Geo – I wouldn’t really recommend putting polyiso on the exterior and leaving it exposed. Obviously if you do things will be even better down there but it’s not mandatory. Making the transition from below grade to above grade and transitioning to the interior insulation without a break it difficult to do properly. Thanks so much for any insight you can provide. I’ve seen previous posts about foam insulation on the outside of the concrete slab, how beneficial is it? Just wondering what is the life time of polyiso foam board insulation. I only have 3.75 to 4 inches in which to place insulation on the floor of my attic (bedroom ceilings). Sometimes you do need to apply some temporary shoring but not often with this product. I wouldn’t recommend doing that at all. Any other ideas how to get an R-Value of at least 30 in a 5.5 inch rafter space without increasing the rafter depth? I’d install at least 1″ of the polyiso, tape the seams, then install vertical strapping to create an airspace, then the siding. Can you please tell me what the thickness should be and if it has to be on the bottom of the slab along with around the sides and it should all the the same thickness or the sides different from the bottom. Using it as an RV really means you’ll also need to cover the foam so that there’s not a flame spread problem. I have been assured by engineers that there is no water coming in any external direct source such as rain and since the problem alleviates when I am away for extended periods I assume it is a condensation problem. Polyisocyanurate also known as polyiso is seen in all kinds of commercial building applications and more recently with residential building projects. You need a minimum 0f 1-1/2″ of foam, preferably 2″. Looks like unfinished basement into an office/den “ Tumbleweed Cyprus ” to sell a specific item – and is... 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