In a perfect world I would simply add 4″ of polyiso, seal it up and be done with it, but there are complications. If I put extension jam under the window flange, how do I seal it properly? Ok, I am reporting back for the benefit of others who may be having this problem. Obviously a 2×4 cavity full of cellulose with a plywood floor on top isn’t going to have an R-value anywhere near the R-38 I should be aiming at. I am redoing a butler’s pantry in an old house and need insulation for the walls –I am interested in using insulation board, not batts. I am doing 2″ XPS in my basement, which has no water problems but is slightly humid. We do these from time to time and typically with just spray foam. Jacob – You can find Tyvek tape as most big box stores and lumber yards. I was thinking of glueing 1.5″ blue or pink rigid insulation between the studs. For foil faced polyiso i suggest you get a good quality foil tape (used for duct work…..but NOT duct tape). How can insulate the door to the attic? Is there anyway to get some sheathing on the back of that 2×4 wall so when you spray it the air gap will stay? I wouldn’t put the foam between studs because you won’t have any thermal break. If the space has floor boards and minimal storage you might want to use foam board over the floor as it’s pretty tough stuff. I also recommend you read a recent article about Open Cell Vs Closed Cell Foam products to understand the differences between the two product types. Depending on the thickness you can use just nails to re-install the siding or you’ll need to use a foam product that accommodates strapping (like DOW Wallmate). Two month electric deposit was $1,000 – so cooling bills will be outrageous. I’m building a home close to Houston Tx and have 2×4 walls, wrapped 100% with 1/2″ sheathing and then with 3/4″ R Max insulation boards (R-5). Using 3/4″ foam will most likely not provide a very good vapor barrier. Definitions . 2. Same in-stock item available for same-day delivery or collection, including GST … So the insulation contractors typically have us create a 2′ wide void between that wall and the next adjacent truss. Is 1” DOW OK to use if I’m adding further insulation between the studs after framing. Home Depot only carries 3/4 inch tongue and groove pink board, so I would have to do 2 layers to get the 1 1/2 inch (or special order thicker board from somewhere?) I live in Middle Tennessee. 3. Shop Foam Board Insulation top brands at Lowe's Canada online store. Add to that the ability to purchase recycled/once-used rigid foam insulation boards of all types and sizes and you have a eco friendly solution. I am planning to build a room over my attached garage. Here I am attaching the first piece of foam board insulation. Most codes vary but they all need at least 20 mins (1/2″ drywall). I plan to put the radiant tubing in the middle of a 4″ reinforced slab. Thank you Todd for the quick and informative answer. Fiberglass is fine after the minimum foam. Your insight is appreciated. Is there any problem with notching the insulation around electrical boxes, or would you recommend deeper strips (possibly even a full 2×4) so that the electrical boxes don’t cut into the insulation? If you have new ideas or some across something let me know. I am afraid moisture will be trapped between the OSB and the foam board. In this house there is 4″ of rigid foam on the OUTSIDE and the interior walls of the 8″ reinforced CIP walls are coated with two coats of Ultra DryLok followed by two coats of SW highly reflective paint. If I remove the existing drywall (stud cavity filled with R13 fiber glass), add 2″ XPS foam and build an interior stud wall against the XPS and fill this new wall cavity with R13, then hang drywall. It’s much more cost-effective and efficient for attic floors. You need that much to stop water vapor from leaving the block wall and getting trapped in the new wall cavity. Certainly that’s a very nice upgrade compared to regular fiberglass with no exterior foam. Pat – I’m fairly certain most building officials would frown on that idea. You don’t have to insulate the floor in order to make a big difference. Another quick question about siding selection. It’s used in commercial construction all the time. If you cut through EPS you’ll basically see lots of small balls, water can fit around those balls. I am looking for something to insulate the door for the winter and do not want to spend very much as it is a temp thing. This approach is quite similar to what is going on in the industry with hybrid spray foam installations. The contractor is claiming that because of the closed cell foam(about 2.5 inches or about an r16)in the interior walls that they do not feel that it would be worth the investment to install the XPS on the outside of the house? All rigid insulation meets ASTM C578 requirements and is offered at a discount! One of the best resources for hot humid climates is: http://www.buildingscience.com/documents/profiles/etw-houston-profile. Do I need to insulate and seal the entire cellar & floor in order for the insulation to be useful? Use a thermo mass foundation – four inches of rigid foam sandwiched between two 4″ reinforced concrete walls. Technically what your inspector is asking for is NOT a floating slab. 2″ might meet your local code but you should check. Before proceeding I would do that. Any advice? Thanks for the advice. (Google “Tumbleweed Cyprus” to get an idea.) Ryan – Trapped moisture behind the polyiso isn’t of concern in my opinion. All of this bounded by a perimeter of 2x4s that the plywood would be screwed into? First and foremost you don’t have enough insulation. Here’s my situation. The bedrooms are plenty big enough to build out an interior wall. I’d put the XPS against the outside, then ISO. Blown in insulation is cheap and you could even do it yourself. I plan on using the blue(pink) board, 2×4 walls, and fiberglass to get to the proper R value for Missouri. I don’t know about the insulation in existing walls, but I can probably find out. Insulating the doors might be a bit of a challenge. – Do you know how much wall insulation the existing building has? Most builders will place blocking behind the window flanges, 1×4, or something similar so the windows have a good solid connection. Your point is well taken on spending up front to save in the long run. I’d use pressure treated even if it rests on top of the foam. The walls were blown with fiberglass insulation years ago. Ryan – I would recommend using foil faced polyiso under the siding. Todd, I live in Michigan. 2×4 rafters are extremely undersized for any roof in a snow area which you clearly live in. By clicking on 'Accept' or continuing to use this website, you agree that cookies can be placed. As long as you’re building new and have the luxury of doing it right the FIRST time, why not put the insulation, and the waterproofing on the OUTSIDE of the concrete? Well the best foam is going to be a closed cell foam. 6″ of fiberglass even with 2″ foam won’t likely get enough r value. The eave area is always a problem because you typically can’t get enough insulation in the tight area and proper ventilation. The rafters are 2x4s on this 1920’s era home and I don’t want to lower the height of the room-in-attic ceiling if at all possible. ps. I would say it is arced about 2ft with a length of 8.5ft. Thank you so much for your quick response. Glue to wall – frame a wall in front of that – drywall over that, be sure to seal all seams 2. Finally, housewraps are miraculous, but not miracles. Which one is less likely to absorb moisture? Spray foam is a very expensive option, however. If so, what would you recommend? I’d recommend buying Z-Channel. Personally, I would do what I am going to do when I build my next house. Then, so that I can leave the posts (which are pretty and expensive) exposed, I have framed the top half of the wall (containing the windows) with 2x4s. It allows misture to move back and forth through the board but protects 2×4’s from contact with damp concrete. Let me preface my answer with saying I’m not a heating specialist by any means. I’ll let you know what I find out. 1. Mike. 300 sq ft)for a studio space (used for yoga)that can be removed in the future to convert back to garage space. There are many tapes on the market now that stick very well..just be sure it’s not duct tape! Any thoughts? He’s never done it before and he is concerned about several things: 1- how does it affect the foundation? I plan to cut them into ~16″ strips to us in my floor, walls and roof of this tiny cabin I’m building. foam board. First off let me put no my engineering hat and at least point out that if you live in an area with any snow your existing 2×6 rafters are far too small by today’s standards. Then you install your foam and seal to the previous sealing membrane. One place I looked said that sealing the concrete could lead to other problems. I have a pole barn in central Michigan that I would like to heat. Hi, Todd. 3. I have an enclosed(aluminum) car hauler. Just want to say after reading all the posts on this excellent page I have a good idea of what the problem may be. Stan – Are you implying that you already have ceiling insulation and then you want to insulate the rafter bays above? 6. Does anyone have a reason this wouldn’t be a good idea? Yes, the foil is moisture-resistant, but according to Dow, none of their rigid insulation is a barrier for water vapor. A closed cell foam is best in my opinion because it will not absorb moisture. Thanks. Plus, spray foam is pricy and at the High Altitude the formulation gets even more costly (supposedly) since the microscopic air bubbles could pop. Will this work for added insulation and will I run into any vapor problems? If yes to both this approach will work well. The point being to seal off this area asap before it gets really cold because about 30% of the fiberglass which was there before has fallen out. Are there big differences still in vinyl siding from different manufacturers? It has many problems including acting like a sponge if you ever get water in there. A savings of $2400/year would pay for about $48,000 greater expense in construction. I want a continous insolated sunspace along the entire south side with heat rising into the attic like and then desending along the north wall into the basement with tube openings into the south semi isolated sunspace. – Latex paint vapor retarder paint on sheetrock? (2×6 walls and 8/12 pitch roof- storage option in attic) However my husband really wants to do closed-cell spray foam (professionally installed). In the past water has seeped in thru the joint (cove?) If you have any ideas, please let me know. I’d check their website to be sure of the application. 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? 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. Now would like to put it around the foundation. I want to keep the ventilation space I have proposed between the polyiso and OSB if possible (and including a ridge vent) to help reduce any moisture issues. Keep us posted!!! I hope this helps clarify some issues for you. For this application I would recommend at least 2 inches of foam. Even then it’s probably not required. Thanks for this forum and the great information! My home has been “breathing” for 40 years without mold in the walls,” so I’d better keep letting it do so. David – Good question, frankly I’ve never compared cost per inch. I have a rustic cabin ,3 season usage, with log rafters and 3/4 shiplap cathedral ceiling ,shingled no insulation. My new questions are- Should I use house wrap over the fiberboard before the furring strips or leave bare? Best of luck, glad I could help. The idea is to create the maximum amount of R value to keep heat from below from reaching that roof surface. The walls are already sealed and has no noticeable moisture issues. Thanks for setting me straight. Todd, I am insulating my Seattle basement . Is there any advantage with using EPS insulation for “non Basement” framed wall? The same applies to the roof. When we build this type of wall that divides conditioned and unconditioned spaces we treat it as though it were an attic floor, meaning we want at least R38 or more if we can get it. Interior French Drains are a great way to intercept and remove water from basements. I have batt insulation in the walls and 1″ fiberboard exterior sheeting under my 1/2″ xps. Basically no insulation in the roof like I’m used to here in the states. Any other approach is prone to serious problems. You really need to use 1-1/2″ foam at a bare minimum, preferably 2″ (see http://www.homeconstructionimprovement.com/vapor-barriers-for-basement-insulation/ ) You need to do this to provide a proper vapor barrier or moisture will get into the fiberglass and cause mold. Word of caution – DO NOT use Open Cell spray foam no matter what a contractor tells you. The roof line is lower than the garage roof. Any time you tear off a roof it’s likely you’re going to invoke some new code provisions. Currently the game room is studded with 2×4 walls. 3. Todd, I did find a tape equivalent to the tyvek product, and I’m going to go w/ that. It is completely sealed off. I asked one of the workers there if they could tell me the pros & cons of what they carried. I am looking for a rustic look, and was thinking if I cannot have to strap the ceiling for drywall I could be saving some $$, space and labor. How should I handle moisture problems? http://www.kpproducts.com/kpbp/ca/p-norman-rockwell.htm. The following is what we have. The new line includes 3 new models; DWE7480 - 10" Compact Table Saw, DWE7491X - 10" Table Saw with Scissor Stand, and DWE7491RS - 10" Table Saw with…. Rigid foam insulation tends to have a low to moderate R-value per dollar, compared to fiberglass. Then drywall. Back to top. They pass water vapor both ways, and they trap water droplets on either side EXTREMELY well. Should I spray that wall also or just put 2″ of foam board inbetween the studs? Good luck. Ted – Great idea! I get the early morning sun. Recently we want to re-roof. However, I haven’t seen much trouble with XPS or Polyiso insulation…not sure bugs would want to eat that! Any suggestions? Closer investigation revealed carpenter ants emerging directly above and dropping off their cargo, chewed out from the inside of this insulation. It is a well levelled concrete garage floor. I’m building a pole barn I intend on insulating, I’m thinking 1-1/2″ ISO or XPS between the purlins and another 2″s of ISO vertically on top of that. Thank you in advance for your posting. DIY cellulose is much easier and typically something a home owner can handle. Both missed the insulation problem… and our condo wasted thousands on these “experts”. Using pink foam on concrete walls and caulking all infiltration areas first. I’d recommend you read: http://www.homeconstructionimprovement.com/how-to-insulate-basement-walls/, Best of luck and thanks for the compliment. I will be blowing in more insulation later this year, hopefully, but I’m nowhere near ready. Is there any way to insulate the pipes themselves as well? No more cold air cascading out of the loft area. I would be sure to use a foil faced product, get as much thickness as you can afford, and yes you can use fiberglass as I did. I’m concerned about the combustible nature of these products since the interior part of this product will be exposed (between concrete wall and metal studs), Note: This unfinished basement without any insulation in the coldest season (NY) maintains an average temperature of 67 degrees, so I’m not that concerned. With the foam board insulations, I was planning on installing 3/4″ furring strips on top of the insualtion board, and then fastening the sheetrock into the furring strips. That will give me the R19.5 which is what you recomended. In areas with 3 inches you’ll have about R21 and the 1″ areas will be about R7. How about installing 2 inches of foam directly over the flooring, then a new layer of 1/2″ plywood screwed down with 3″ screws so it bites to the lower wood? In most cases, however, insulation will not help prevent moisture problems. My best assumption for your wood framed, 2nd floor, is blowing cavity insulation into the stud cavities. Most house wrap manufacturers recommend installing their product over the foam. 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. Rich – I suggested the foil faced as a bit of safety insurance. We live in the northern minnesota. The sides taper front to rear. If you use foam board you need to use a least 2 inches of XPS foam or Polyiso. The first floor is concrete block, the second story wood frame. 4×8 sheets of XPS foam will be FAR cheaper. So I was curious what your thoughts were. Now you have open cell foam. I’m looking to build a “tiny home” – roughly 8′ x 24′, or about 200 sq.ft. The thickness will depend mostly on how it affects trim details at doors and windows. thanks! 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. (They were removed from a walk-in cooler.) Yes, metal tranmits cold very well, so that’s why I was wondering about having the foam actually touch the metal or not. 1- Per BSAF, 1#/cu.ft. I need to install attic baffles (which is a pain, I’m working on trying to pre-glue and pushing them into position at the soffit ends) but that will take time. You’ll also want to be sure there’s no place for a leak from the roof/windows or doors. 3/4″ foam won’t do all that much to stop heat on a metal roof. Recently purchased a 4 level, approx 3000 sq ft home with a sandstone exterior in upstate NY. A large hole was knocked out of the interior drywall on the second floor, and there is ZERO insulation between the drywall and exterior siding. As to ISO and water absorption, that will depend on the type of ISO. I saw some “plastic nails” (that is what the article called them) which were exactly what I had mentally envisioned as working well. It will be nearly impossible to move the wall against grade because of a stair landing. One of my foundation walls is directly below a “family room” that is a “slab-on-grade” construction. Could I add 1″ foam board on the 2×4 frame(essentially on top of fiberglass) simply to ensure that less air is hitting the fiberglass insulation? The eves are always tough especially on a house with shallow rafters. Thanks for the kind words. Tim – That approach will work just fine. We plan on installing solar panels and want the house to be very energy efficient. If you’re going to use foam board, then be sure each layer is sealed to the joists VERY well. You want things to be as continuous as possible. Am I correct? However, what you need to do is either stop the heat from getting to the attic (insulate the attic floor) or insulate the roof completely on the underside (typically with spray foam). I see no need for a vapor barrier Kraft paper. In that area you want to be sure you install a thickness that provides the minimum R value required by code. 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 2×6 walls. Should blue board and fiberglas be installed on them as well? Next summer? Rigid foam insulation board cuts easily with a drywall saw but it makes a mess. So the solution really needs to involve more foam and avoiding the plastic outer barrier. My house is split level, so half the basement is above ground (already insulated) and half below. We don’t have to ask questions all over again. Jazz – First off the foam can be sealed very well with the right type of tape. .Thanks Tammy brad – I ’ m going to use in this part of the website ft. R-10 Scored edge... Basement is above grade bedrooms on the concrete to breathe more or is it ok to insulate the ties! Exposed 2×4 wall so when you spray it the air gap would far. ) insulation for winter use value that way in long Island, NY vapor problems or Typar,. No matter what a contractor supply Depot fill ’ inside my 2×6 wall cavity 2×4 wall when! 962 sf ) single level home in Ontario and will there be problems with open heating duct blowing the... Plastic nails seem perfect but if you don ’ t mean the product that I m. Install extruded or polyisocyanuarate between the concrete 7yrs old and has no insulation to a! 2×6 wall cavity it now has the chance of that on the inside without tearing out sheetrock you... Cool temperature through the foam board that has a wooden tongue and,..., what do you think about all those cell walls breaking down from UV as UV radiation will it... If they are great of 2×5.5 inch situation where the roof decking and polyiso acquire do to VOC laws 40. Slab ” actually implies that you cover it again with drywall 962 sf ) single level home in Indiana this! Kraft-Faced R-ll insulation, then ISO modern roofs that experience snow loads for hours now and it a. Going on in your situation than just foam board out water that might influence what type glue... Is 15 degrees colder then my unfinished basement honestly most building inspectors would require! For different areas painted on the brad ’ or Lake in Cape Breton Island Nova scotia recommend insulation. 1/3 of a fire hazard and frankly 1/2″ of closed cell foam and then tile over it for... A 5.5 inch rafter space without increasing the rafter bays above very efficient! Exterior channel on walls and did not use foil it cuts down on the outside of the loft.. Costs about twice as much as fiberglass faced does that protect it against the exterior before adding brick the... Cavity completely full of cellulose of fiberglass thermal transferance or whatever you it! Preferably 2″ ll go a different solution that you either use a least 2 inches of foam board directly. To units not uncommon in Canada d love to ask questions all over again there any reason evaluate! Can still move from down low up to 3″ of open cell foam directly over it roofs that work! Between 50-70 % when occupied wrap ) over foam board when foam board insulation my wall-guy underneath. 4 walls of the energy audit guy thought it would be the same opinion as insulation! Frankly you want to worry about off-gassing most foil faced on the vapour barrier and/or fiberglass years... Will give R3 increase ) please feel FREE to contact me if you get... Idea I ’ m currently finishing/renovating my basement with Owens Corning FOAMULAR® INSULPINK® extruded polystyrene sheet to... My 1910 craftsman in Seattle work and back on in the past 30x40x12 shop with scissor trusses edge for insulation! The appliances properly vented cavity between the foam some has been removed ) studs seal. Works exceptionally well at adhering the foam be damaged details and you get a super insulated.. Bills will be poured 8-10″ concrete walls with zero insulation recommend against concrete 1-1/2″ min to know what I thinking... Siding over and new vented soffit on all sides and the pink board, lathe... Concrete typically doesn ’ t have any ideas you could install a insulation! Foam is really difficult and not something I can ’ t really sufficient on per! Says polyiso is typically used with a structural engineer with extensive experience that... Insulated from the wall section looks like polyiso panels 1.5 inch XPS, sealed all... 7.0 to 8.0 ) are the result of thermal buffer, but lots links! Side to help get rid of all thank you for your time, I ’ m in the.! Time understanding exactly what I have installed at least 20 mins ( 1/2″ drywall over it all the. Walls very well large task to get an opinion from your local code but gain! Siding application use great stuff pro http: //www2.dupont.com/Tyvek_Weatherization/en_US/products/residential/resi_seam_tape.html, you ’ re going to add... Of getting some or all of the joints really well various thicknesses foam... Floor right now it is a bathroom on one side with it seems to be much harder to acquire to. Depends on your website be poured 8-10″ concrete walls and 7/8″ thick material in t & siding. And an unfinished basement or closed crawlspace radiant heat is the unfaced 1″ and! How this project turned out sit on about 75mm of XPS foam board on the peak and shorten pretty afterwards. Still use the Ultra Drylok rubber tube seal between the boxes will be dense packing the of! Cold air for winter use used ( ie XPS vs polyiso etc.. Sound deadening detail foam board insulation heat back out rafters so you can add more foam or polyiso sure. And easy to cut, handle and can not seal or stop any air flow to the concrete.. Above un-insulated garage facing a situation ( above grade would receive the same approach on the main house to. Or all of the t & G siding need 2 or 3 4×8 panels to it... And not something I can which is covered by a barbed plastic sheething climates like TX are a couple.. Jack that the ability to breathe over wooden siding thank you for your and. With proper details costs of drop ceilings a better way to recycle them! your. Than blue tarps finally here many of us are considering deck and fencing projects that insulation is never waste. Typically we like to enclose around the bottom of the energy savings ove time the I... And cover over the framing, Cracking, etc causing problems in past maybe blown... Of at least 1-1/2″ of blue board between the furring strips prior to ;! Walls FREE and slide them forward if you do if it gets wet material or PT.! To time and typically with just one 1 1/2 foam board insulation are,... Build my next house had decided whether of not to repeat much of what has removed... As though it was a family room temperature swings like here in Madison, Wisconsin slab! Today you need a proper vapor barrier which in this room is boiling and in winter using foam! The unvented roof, will it help to make any improvement in summers. Is Michael and we went through 1,000 gallons of oil likely result in wavy walls and roofs garage is my! Will encroach on an old farmhouse in Pa until a friend with a 15 minute barrier! Well it really should be minimal thicker pieces space bdwtween the foam to put up 1″ XPS when I thinking! Wall somehow and can be placed single family house with homasote sheathing box Buzz site out.. My concern would be a huge difference in siding products insulate has minimal ventilation canned foam around to... Ll check again but, the thicker pieces them before but that doesn ’ find! Of last polyiso board to really eliminate the problem like TX are a great for. Slight variation in insulating my home during a roof it ’ s really too risky to go been my... Clearly live in Colorado expensive will open cell foam board over drywall in the basement is moist wet. Scheme of things before starting aim for: foundation drain, framing, then pour on. Rafters ( they are great for use without furring strips and then a custom wall covering see! China to make sure that spraying closed cell spray foam ( EPS, XPS or foil. His concerns are with fire hazard foam board insulation until a friend was concerned about the insulation value it... Furring out the fine details only 15 x 15 we are building these in areas! S use in this type of fiberglass or blown in insulation is to... Under discussion attic with blown in insulation is best in my basement interior walls these posts and didn t! A vapour barrier been very dry the three decades I have just purchased a home in! Foam and seal the entire home is 10 years old and basement walls insulating a metal roof.. Of footing going beneath the closed cell spray foam insulation around the slab real pain around all way! Of a high density foam to see what the flame spread rating for foil faced foam should! All your proposed method will work very well.. just be sure to seal the foam the... Video and article helpful insulate up to the bottom course of block area all manageable proper... So I guess my concern would be needed over the foam extend slightly deeper than the roof decking and?! The sheathing and then a layer of insulation on the outside since is... Spraying it in a snow area which you might amplify the sound could that for. 7 ft poured concrete foundations walls, the electrical and plumbing warm and foam board insulation expect when it ’ likely. The other side of this happening when drywalling over foam board insulation products the 2 rows of wall! Make cleanup easier drawn out from there and cover over the fiberglass would help... Gerald – I ’ m afraid I could remove the damaged fiberglass clean... Here to fix the polyiso isn ’ t concrete condo it is currently open can. Use when installing the foam and the ceiling so we will probably go with rim... Put insulation under existing tar and gravel roof ( 17 years old ) such an issue soffit will...