What does /diy/ know about insulation a crawlspace? I live in the south and bought this house in the fall, didn't have to touch the A/C for heating or cooling till like December and my power bill more then fucking doubled. I do know the crawlspace is uninsulated, but it has those vents so its "open".I read that spray foam is the easiest to install but might be bad long term because it can trap moisture, but I fucking hate dealing with fiberglass. Would it be a good idea to spray foam in places unlikely to see moisture? The house was designed so all the plumbing is in one small area. So maybe just do fiberglass around there and foam the rest?
>>2971565Spray foam being a moisture barrier is a feature, not a bug. It's only an issue if it picks up moisture from the inside, i.e. leaking pipes or condensation. If you have leaky pipes, the fiberglass will soak it up and lose insulation value, so it's also a bad choice there, the way to go is fixing the leaky pipes and then insulating. You could stop-gap with EPS maybe and intentionally leave some small gaps to let water out in case you spring a leak, that'd still do 98% of the work insulating the area.
>>2971565rockwool exists lol. its maybe 10-20% more, its slightly itchy, basically fireproof (1800+ F melting point), and its moisture resistant.
>>2971571i bought some loose rockwool is it true you have to fluff it up like cotton candy with an animal wool carding like process to give it air and volume for insulation
>>2971565Not that the crawlspace is unimportant, but the type of heating system you have is far more important. Is it a heat pump? Resistive heating? Is it old? Before doing anything radical to the crawlspace, find out how efficient the actual heat generation is. Also did your power bill double from the summer average, the last month of autumn, or the annual average? Autumn is temperate in the south, so the bill in December being double might have been as much about November being a low usage month as it is about December being high usage.
Start out with identifying where you are loosing heat. Either borrow a thermal camera from someone, or buy one. You crawlspace need to be ventilated, to get moisture and radon out. Personally i wouldnt use spray foam, because it traps moisture. Rockwool is he way to go, since its more fompact wise. So there are less loose fibers. I did my entire attic 6 years ago, added 145mm rockwool to it. I would say it was just as time consuming to raise the walkeay, as it was to lay out and cut the bats to size.
i have been in some nice crawl spaces and seen some ugly ones, the major difference, was the grading, ugly was lumpy difficult to see from one end to the other from your photo that looks nice.id seal the home first using an incense stick/cone will produce a visible smoke trail that can help you locate drafts and it burns colder than a naked flame, id choose careful that scent lingers. spray foam has a narrow application temp window, screw that up and you are potentially poisoning yourself for years, a thermometer should be part of every spray foam kit.the moisture issue is a big problem in the UK there has been talk about insurer no longer covering roof covered in spray foam most likely because of the moisture problem i have no tricks for fiber glass, cold showers do not sweat and it should only suck for a few days.
>>2971792>but the type of heating system you have is far more important.I'm thinking your RE Agent fucked you in the ass and there is something seriously wrong with your system and its basically pumping $100 bills into your neighborhood and you are "heating every house on the block except your own".Please post details of RE sale and agent's lack of input on your Heating in this thread. >>2971891Ditto on the Thermal Cam. I had a SEEK Thermal plug into smart phone and it was amazing (got stolen with backpack). Best outdoor etc thingy ever. Its like being The Predator.I think any RE Sale needs to include a Thermal scan of house in relation to outside temps to gauge future HVAC bill. Just make the temps as different as possible and AI should be able to sus out the rest. I'd go with Rock, if fiberglass gets wet it can create a weird cycle where the wet causes cooling and the cooling in turn grabs water by lower Dew Point, so it stays wet until it rots your joists.BTW, WTF can be easily and cheaply sprayed on raw wood framing to prevent rot, mold and termites, that isn't too toxic and wont be a big shit deal if I have to sell the house and some Inspector eyeballs it?
>>2971907>wtf can I sprayBorate. Bora-Care or something like that, preferably with a mold treatment. It's mostly water, so as long as you saturate the lumber, it'll wick deep into the core of the wood.
>>2971565I need to re-stump my place like this, but have limited space to crawl around under there and the water level in the wet season is about 1ft/ 300mm deep so any concrete foundation i dig will attrack water to sit under them, anyone got anyvadvice?
>>2971968"sleepers", beams laid on ground, like PT 4x6.I'm thinking wouldn't be Code but if they were connected and made rectangle or had angle braces from joist it could be OK and they would stay put.Then some sort of jack to adjust them tight to house if they start to dig in.
>>2971911>Bora-Carelooks good, seems like should almost be a Code in lots of places.
>>2971565You need to be careful with how you handle insulating your crawl space.https://buildingscience.com/documents/building-science-insights-newsletters/bsi-115-crawlspaces-either-or-outIf you want good advice you will need to provide more information about your crawlspace. Dirt floor? Ground sheet?Wall construction? Height of walls? Size and number of wall vents?Floor above's construction? Does it have insulation or moisture barrier?
>>2972527Its a dirt floor, its both above/blow ground cus its on a slope. You can almost stand up in half of it and its cinderblock walls.
>>2972912is there any insulation in the floor joists currently?
>>2973247None.
>>2971779>>2971571I‘m considering doing my small attic with rockwool and simply laying it out on the floor rather than putting it onto the roof to save money. It would also be more effective for keeping the house warm, I believe. Should I plan to add in some wooden beams for traversing the attic or something?
>>2971797Any tips for someone doing that? Anything I need to be sure to do? Any guides you’d recommend?
>>2971797can you do it with an ir gun
Go to your nearest hvac company and dig out old pipe insulation from their dumpsters, free. It's good to ask first, but most won't care, youre actually doing them and the world a favor. It's better than backed fiberglass because once you slide out the wire plastic wrapped tube, it's all still premium fiberglass left but with a reflective foil shield also. Very easy to handle and very warm. I've insulated many buildings for practically free this way.
>>2973801Then I would recommend doing "crawlspace encapsulation" instead of insulating the floor.You insulate the perimeter walls with foam boards and close the vent openings. You install a continuous poly sheet on ground and walls.the crawlspace now dry and clean connects to the house with some ventilation. Having conditioned space adjacent to the ground will regulate your day/night temperatures. You can also store things down there without them rusting/growing mold.
>>2974275I agree that crawlspace encapsulation is usually better than stuffing insulation between the joists, though the condition of your walls must be considered. If you seal one side of your concrete walls, but they are taking on water from the other side then they aren't going to be able to shed it and you're putting a premature expiration date on your foundation. You usually want a drainage system in place on the exterior side of the concrete wall and even then, if you live somewhere that is wet, you don't really want to *seal* the interior side. Giving the inside some space for air to move across the concrete would probably be good. Doing a gravel-foam cap on the ground would probably be s good way to go, although an actual rat cap should be a consideration.
>>2974296True. The ideal is as in pic related where the waterproofing and insulation is on the outside, keeping your foundation dry and temperature-stable.
