Trim lengths of paper-backed insulation so they follow a joist bay from one rim joist to the one opposite. Otherwise, moist inside air could condense on the cold rim joist (band joist). What Are the Best Tips for Floor Joist Insulation? So when you say you had moisture problems and 'replaced' the vapor barrier that made me wonder if it was the problem. 5. Our real estate agent says she has done this with several of the old houses she renovated. The hydronic system is above the sub floor and covered with a finished concrete FYI. The space is pretty flat and there is lots of room to crawl which makes it much easier to work in the space. So it feels like I was sold a partial solution then that really doesn't put me in a better situation than what I already had. I can insulate the interior of the exterior wall due to the termite treatment and annual inspections required. Are you suggesting putting rigid foam over the barrier on the floor? If I did that would the cold air just seep through the walls of the crawl and up into the house? Seems there really isn't a good solution due to the need to monitor for termite activity. Hi Kevin, thanks, glad you are enjoying the site! Rock wool(mineral wool)boards are an alternative product you can use and they are made from recycled stone dust, so it does not burn and does not need to be covered for fire protection. And I recently had a contractor replace the R19 backed-insulation in the crawl space. And for house shopping in case you ever move. The insulation should press right up against the floor between joists; gaps between the insulation and the floor can lead to inefficiency and heat loss. - Never had a dehumidifier under the house before, is that something we should do? Maybe in the rooms too. We have the ones for the shelves in the closets and some rooms with mold proof paint. But we do get some mold at times. The Ocean air, - Im looking at quotes for Spray Foam, but I work for a Heavy Civil Construction company and I did most of the land moving, forms, rebar, water lines, electrical for my patios. So I tend to be a major DIYer. But if that price is over $2000 or so to have them spray I have more Time than I have Money!, - Should we treat the dirt with vinegar first? Or a different Mold killing product?. Please advise if I am missing something here? Spray foam is done quickly, it has a high R-value, provides an air and moisture seal and fills all the tiny holes. Copyright @ 2008-2022 All Rights Reserved, Floor Joist Installation - Between Joists, Wall Joist Installation - Between Joists Over Existing Insulation, Easy installation (see below on How to Install Floor Joist Insulation), Versatile enough to fit between joists or attach directly underneath joists, Very durable and can't be ripped or torn by hand, Safe to handle and requires no special clothing or breathing equipment, Scissors or a sharp utility knife to cut the product, Construction staples - 3/8" wide is a very popular size, A staple gun - mechanical, pneumatic or electric, Recommended - Someone to help hold the product while installing. He also replaced the poly covering the dirt. You can walk on them a bit without doing much harm, or you could just put them aside to reach a further part of the crawlspace if you needed access and then replace them after. The first thing to mention is that if you have an uneven surface of solid rock in a basement or crawlspace you are at risk of radon gas contamination, so venting is good for now but I would think of a longer term solution. It's designed to be installed in the walls and floors to help keep your building cooler in the summer and warmer in the winter. Home House & Components Rooms Basement. for sure if most of the wall is exposed then R8 or so of insulation isn't a lot for Manitoba. If open cell is used, does it need an additional vapor retarder on the interior side, e.g. This is a significantly more expensive solution, but it will work very well.. 1st off, dont know how i didnt find this website sooner!! Check with your local authorized Basement Systems or CleanSpace Crawl Space contractor for specific warranty information. Lastly, are you concerned with spray foam hiding termite activity and what do you think about spray foams using soy?Lots of questions. Kansas. What is the best thing to do. Also we will have a large dehumidifier as part of the package with either type of foam we decide upon. Work the insulation around pipes, wires and heating ducts. I have not done anything to the cement floor. You could spray foam the entire interior (walls and floor) and then there is no need for a radiant floor above since the warm air below will keep the floor at a comfortable temperature. So I would consider a radon gas venting solution and then close the vents. They are, both, acceptable ways. Rotten huh? This is relatively easy, and we don't have to pay anyone to do the job for us. We live in southern Georgia. At the very least, laying a 6 mil poly vapour barrier will keep the moisture down., For the addition that is on concrete piers, if that means air (and wildlife) are free to travel underneath it, then you could consider spraying the underside of that if you have a spray foam contractor there anyway. and can you insulate the interior of the exterior walls?. 6. Either way - if its dry, the walls are insulated, between the joists is insulated, and youre in a reasonably mild climate, I think as long as your feet are warm enough then there is really no great urgency to undertake any major work. If I was to do the EPS foam on crawlspace floor would that help much to reduce the heating costs of the home? Whenever possible, run the insulation between the obstructions and the subfloor. One of the first decisions when building a home is what type of foundations to sit your home on - cold-climates, termites, problem expansive clay soils, insulation & vapor &, Removing radon gas from existing basements and crawlspaces can be very effective, here are different options for different situations. (not sealed) You would think that would do it but no. My question is what do we do to prevent it from happening again? If as you say, the floor is only dirt covered with a vapor barrier, then there would be heat loss there. I'm curious as to the answer to your question George. I also have a small crawl space under a cottage that is too small to access. I'm thinking I'd put down the 5 mil poly using poles to spread it out as best I can, but wonder if it would help to then blow in cellulose on top of the poly for additional insulation. I live in New England so widely varied temps. BTW - great informative article! This is a conditioned crawl I think? https://www.buildingscience.com/users/joseph-lstiburek. What Are the Different Types of Fiberglass Materials. What about the existing crawl space ventilation vents, would you suggest leaving them open, or sealing them. Run sections of insulation from the rim joists to the crawl space or basement floor all along each wall. Would foam board along with sealing rim joists be where I should start? He holds a bachelor's degree from the University of Arkansas. But mineral wool is not a vapour barrier, so it is best to apply a poly membrane against the concrete first. I have a cottage which we want to use all year and it is open underneath with insulation on the underside of the cottage i.e. He said that it would void the warranty as termites will tunnel through it. Closing Crawl Space Vents in the Winter - Good or Bad Idea? Thankfully the cinder blocks are in great condition and at low risk of damage in my climate. Vent- NO vent.Insulate the floors for the hydronic floors to be more effective, etc.. You can read more here about how heat loss happens through conduction, convection and radiation. Properly insulating and air-sealing rim joists (band joists) takes patience, so most builders simply stuff in some fiberglass and walk away. It's separating the humid, spider and bug domain from your home. Part of the problem with adding insulation for floor joists is securing such insulation between joists underneath the floor. Possibly a dehumidifier too. In a cold climate like eastern Canada, where the situation is complicated by high water table (low flood risk), which would be the preferred foundation in your mind; a raised slab (stem wall) or a vented crawl space to accommodate hydrostatic issues in the unlikely event of flood waters? Any help is appreciated. If you have an unfinished basement, you can properly insulate the rim joists in two or three hours. Do these different goals call for different solutions? If you have a solid concrete foundation, also run a bead of caulk where the sill plate meets the concrete. So. 1. maybe 18" in parts. However, challenges with properly installing fiberglass batts make blown-in insulation or rigid foam a better choice for insulating the ceiling in unconditioned basements, crawl spaces, and garages. If it is then remove it, but if it isnt moldy and you have a poly barrier and a dehumidifier, then it likely doesn't need to be removed as you will have dealt with your humidity levels and that is what causes the problem in crawl spaces. Lay down a moisture barrier with sheets of 6-mil plastic if you have a dirt or gravel floor. 1/2 of the basement is finished off. Is Roll Insulation Installed With the Backing Toward the Room or Toward the Outside. To add to the problem, most garages, basements, and crawl spaces either dont have insulation at all or dont have proper insulation. an exterior horizontal (laid flat) skirt of insulation buried under the dirt would also stop a lot of heat loss if you were going to go that route of insulating and backfilling., Rodents is a whole other issue that you for sure would want to deal with first, here is our page on removing pests and rodents safely , there may be some info there that could help.. It's just worth a look first. The crawl space is unheated but I am wondering if it makes sense to sprayfoam the walls and if so whether to use open or closed cells? Wouldit be costly to condition that space on a large foot print house and what is the benefit if so. I would like your thoughts on this, and in this scenario would you suggest leaving the crawl space exterior ventilation vents open or closed? When fiberglass batts are shoved into the ceiling in the basement, crawl space, or garage, the compressed insulation cant trap as much air, making it less effective at reducing heat loss. Above in the floor joists is fiberglass batt insulation. Would I be best to replace the skirting with something rodent/insect-impermeable, lay a vapor barrier, and spray foam to seal/insulate? This makes it difficult to fit the fiberglass batts without leaving gaps that air can easily flow through. The paper should maintain contact with the subflooring but avoid compressing the fiberglass insulation. Since 1987, Basement Systems, Inc. and its network of affiliated contractors have helped restore peace of mind to thousands of homeowners across North America. Should I be concerned that there is no longer a moisture berrier between the subfloor and the top of the new insulation? Thanks so much for the wonderful information! Youll have to change all our Building Codes for that to happen., There is a lot wrong with building code, so we're doing our best!. Check out this page about finding spray foam with lower emissions to be pick the best brand. I currently have 6 mil plastic on the dirt floor and the previous owner installed unfaced insulation between the joists. Is it the visualization of bug life below the vapour barrier that has you looking for other options? That really sounds like a hassle to build and I think it would be pretty costly, I would suggest instead that you price out the option of applyingspray foam on floor of the crawlspace. - There might be some minor cracks in the stem wall foundation from the Earthquake in 89, but the siding comes down low to the ground, so not sure how well I can seal that from the outside or inside. Maybe the water / moister is coming up from the ground? The goal of insulating would be to lower heating bills over time (and given my electricity is green in Quebec, getting a pay back from this investment), have warmer upstairs floors and reduce dampness which could contribute to mold. Important note: The following crawlspace solutions are recommendations for how to deal with moisture and heat loss only, and provide only an anecdotal overview of how to deal with radon gas. Insulation doesn't 'attract' condensation. Can we not condition. Open to all input and help on the matter! One guy told me that once he removes the insulation that new insulation doesn't need to be added. Doing the walls would be great as well, but in terms the floor and 'radiant heat transfer', the warm air of your crawlspace will warm the dirt floor continuously, foam on top will reduce that pretty significanlty I imagine. Air contaminated with radon gas is a serious health hazard and is the second leading cause of lung cancer after smoking. Don't worry about cutting the foam for a tight fit around pipes, cables or other obstructions; you can seal large gaps with expanding foam sealant later. Insulation works by trapping pockets of air that slow the flow of heat out of the house in the winter (and into the house in the summer). I'd pretty much always choose a slab unless there is a need to be below grade with a basement. Is the dirt floor flat enough that you could lay down sheets of rigid insulation? Hi! This is a very informative article on crawlspace insulation. First off, very informative page for crawlspace issues, thanks! I have a concrete block crawlspace of about 900 square feet under our main living floor in a housenorth of Ottawa. Once I got the cracks filled in, I noticed an immediate improvement in the comfort level inside the house. Basement Systems, Inc. 2002-2022 All Rights Reserved. When the temperature drops outside the wood floors tell the story. to keep the areas around better insulated? I have removed and taken all non wood items to an annual garbage barge, I am now removing wood and rock, to give a semi smooth dirt floor. Iwould repair thevapor barrier first and make sure it covers the entire If its ripped and in really bad shape theninstall a new one if you have to;this is also the time to do a passive radon stackif you don't already have one. We make no secret of the fact that we aren't huge fans of spray foam due to the emissions associated with it (with exceptions for eco-friendly spray foams) but this is one place where it can make a lot of sense. The humidity stays around 46% in the crawl space but the temperature stays around 80F. Myhardwood floors have been cuping and was advised to have a dehumidifier installed by floor folks. Family Handyman Reader Projects: Indoor Spaces, Do Not Sell My Personal Information CA Residents. Do the best job you can and seal the joints, but remember - if you did nothing else beyond laying it down over most of the floor, even without taping or sealing it, you would reduce the amount of moisture in the air. The inspector may require you to cover the new insulation with drywall (as a fire block) or leave some areas uncovered to allow for termite inspections. Unfortunately for us. this was untrue. 7. To ensure professional installation and superior service we carefully created an international network of over 350 trusted basement contractors. Let me know what benefit you see in that, I can't think of any off hand. Aluminum sheeting is fairly lightweight, but it can also be damaged fairly easily. Call your local building inspections department before you begin this project. Building codes often call for these vents as a means of circulating air in crawl spaces, and sometimes in basements. Thanks for this great service! There won't be anything appealing going on underneath the vapour barrier, no question there, but that membrane isthe opposite of an invitation. Is there anything I can add to level the floor out some before reinstalling new poly and taping it? Airtight insulation reduces heat loss through the rim joist (band joist). An error occurred. Should I put the new one over top of the old? If there is no insulation between the crawlspace and home above then you're just treating it like conditioned space, so it's best to have the exterior insulated if you're going to do that. The house floors are pretty good, they get a bit cooler, I wouldn't even say cold when we have one of our short infrequent cold snaps. This makes me nervous and I worry if workers under thereCouldtear the plastic and we would not know! I have seen the batt insulation at the home improvement store where we shop. I beleive R20 is to code here. At that point the crawlspace is part of your heated space, so there is no need for a thermal separator between above and below., My crawlspace is similar to one of the gentleman who was seeking answers for his crawl, which involves hydronic in floor heating. Common building practices trap moisture in wall assemblies preventing them from drying. It had signifigant termite damaged wood which has now been replaced, and then was fully spray treatedby the local termite contractor. The long-accepted DIY solution has been to add fiberglass insulation to the basement ceiling. Unfinished crawlspaces really are a source of moisture and mold, thats why its so important to keep the damp down to mitigate heat loss but also protectair quality. This is not an 'all or nothing' situation where there is no point doing anything if you can't do it all - do as much as you can, it will help. Thanks. This started happening around May/June and i believe this is the reason our house stays so hot. Avapor barrier needs to be on the warm side of the insulation.. Can we add siding on the underpart of the cottage on the exposed plywoodframing we will be usingto frame the exterior at a latter to protect the plywood and is it okay if the plywood is pressure treated or should we not use pressure treated?Or do you suggest using decorative trellis instead? And if they are just laying there and you need to access a farther point in the crawlspace you could just lift them to pass and replace them after, assuming you don't need to do this regularly. There's no insulation in the crawl space or floor joists . I've seen houses that are waterproofed from the inside, with a french drain and foundation wrap (draining into a sump) but there's no mention of that type of waterproofing in this article. I still have the original batten insulation between all the floor joists, there is no vapour barrier with it. Why your floors are cold and the best ways to make them warmer. I was also told by our inspector that our insulation in our attic could be more sufficient so that will be on my list as well., You're in a pretty forgiving climate for Canada, so if its dry, your feet are comfortable and your bills are reasonable then it's not a really pressing issue., Thanks for the information, much appreciated!. Whether you are looking to add insulation between joists, or directly over the top of joists, EcoFoil has a solution to fit your needs. Depending on the size of your home, you may need more than one piece of insulation to complete the run. Or is this assumption incorrect due to the foundation type?, Due to the small footprint, I was also considering heating via radiant floor heating. A crawlspace is best treated as part of the conditioned space. We don't get too much below freezing in the winter. A layer of carpet is a good way to provide a layer of insulation from the cold outside air. The first thing we would recommend is removing the wet and moldy fiberglass insulation. Should I use faced insulation? I would pull a batt down for a look, and if its perfectly dry then thats pretty much all you need to see to know its doing fine. Where is the vapor barrier and on which side of the insulation - warm side or cold?, Due to the termite treatment and the need to inspect it they said we really can't insulate the exterior walls. So I'm stuck with a space under the house that is essentially at the mercy of the weather elements temperature wise and I wonder if it is just going to drive my heating and cooling bill., Vapor barrier is laying on top of the dirt and taped a few inches up the walls ins the crawl. Other than the vapor barrier being new the only thing different is that I now have a dehumidifier system. I'm not sure what warm or cold side is for insulation but since it is in the crawl I would assume that is the cold side., That's good to hear on the vapor barrier, covering the dirt in a crawlspace is the single most important thing to do. Our between joist insulation is constructed with a double layer of polyethylene bubbles bonded between two layers of radiant barrier. Given the possible usability of the basement (storage and mechanical devices) would you recommend then pouring concrete on the insulation to level everything out? If the batts are starting to fall down you could remove them and re-insulate between the joists from below. This has not been the case. We know that we need to remove the old vapor barrier, insulation, and construction debris. Worse, theres a risk of car exhaust, paint, solvents, and other contaminants in the garage migrating into the conditioned space. The crawl space is actually dirt floor and has had vapour barrier and vents sealed. Spray foam is then applied to the walls behind the studs and into the cavities, you can leave enough room to do any wiring if required. When the basement or crawl space has vents installed, insulating joist bays prevents cold drafts from penetrating into the homes interior. If you have an unvented crawlspace or basement, you must insulate the walls instead of the floor joists. We have cold floors. More and more houses are simply putting poly down and putting spray foam on the walls. CleanSpace crawl space encapsulation is the solution you need. Another common mistake that homeowners make when insulating a dirt crawl space is adding plastic (or a vapor barrier) to the underside of the floor joists in an attempt to make their floors warmer in the winter, but doing so can trap moisture that can lead to mold and rot. 8. Run a bead of acrylic caulk around each section of foam to form an airtight barrier. Thoughts?. And yes on the dehumifier, try to keep it below 50, even 40% RH if you can. We will then back fill from the outside to prevent water from getting under the cottage and redirecting the water away from the back of the cottage to either side (ditch, gravel and weeping tile). As for the critters we are hopeful they will go away :). Doesn't appear to have any standing water or mold issues. How to Finish, Frame, and Insulate a Basement, How to Install Basement Windows and Satisfy Egress Codes, How to Install Under Cabinet Lighting in Your Kitchen, Basement Waterproofing: How to Install a Basement Drainage System, Metal Studs: How to Use and Frame With Metal Studs, How to Install a Terraced Window Well in Your Basement, Basement Carpeting: Installing Carpeting In a Finished Basement, Damp Basement: Finding Leaks and Water Sources, We are no longer supporting IE (Internet Explorer).