Instructables

DIY Home Insulation

So I know I need to better insulate my attic for the coming winter but, money is tight and the to-do list is growing so I began thinking of alternative or DIY materials to do the job. I know Cellulose insulation is shredded newsprint treated with chemicals to make it mold and creature resistant, and on a small scale maybe that process could be a fun experiment, but not for 1000 sq ft. My next thought (and current favorite) is to acquire styrofoam packing material (box inserts, packing peanuts, un-used food and drink containers) and mill them up to about the in to some uniform size. Then get some cheap plastic bag/ tube material and fill strips with a couple of inches of styrofoam. Then the blanket o’ foam could just be laid out over the existing insulation in the attic. Now, before I start this endeavor I thought I would check with the instuctable think tank to figure out: A) any better ideas 2) what R rating a 3 inch loose fill blanket of styrofoam and plastic would have III) Is this a terrible idea due to moisture being trapped under the plastic Also in a previous forum someone suggested re-routing their dryer vent to the attic and I was wondering if anyone had tried that and/or anyone’s thoughts on that. -Odo

Leafgreen1 year ago
I just wanted to share that I spent thousands of $ insulating all over the house. Then, sitting in my home office last month, I feel a strong, cold draft from the vent register. Doh! A source of lost heat!! Decided to cover them. Went on a google safari and found these: http://www.gadgetsgo.com/airconditioners-HVAC-heater-floor-vents-cover.html. Cost $25. Came in a couple of days. Installed in moments and now I'm more cozy and saving energy. FIY!
Deftones112 years ago
very good idea! :lol:
rcarroll52 years ago
you DONT want to vent ur dryer in the attic because of MOISTURE u will have a big mold problem if u do that. you dont need to take out all your old insulation either if your house is old it probably has knob and tube wiring. knob and tube wiring creates heat leave the old insuation in there for a banket over the wiring. you could locate all you junction boxes and splices and flag them but put the old insulation back where it was. cellulose is inexspensive about 5 dollars a bag. 1000 sq. ft. u will need maybe 40 bags to get a r-value of 38
glassman082 years ago
I had recently insulated my garage with FREE 5 1/2 inch closed cell foam board
[ RECYCLE from local roofing company - flat roof]
I used caulk made for adhesive for foam - AWESOME material

House was built in 1800 [dble brick walls] lathe & plaster walls, limestone foundation ... searched the internet ... foam is the choice of many

Used foam in basement between floor joists [sprayed expanding foam in can around foam board-airtight seal] Also used foam-board on foundation walls with caulk to keep in place. Will finish with framed wood wall in spring.

IF WATER DOESN'T PENETRATE IT - AIR DOESN'T HAVE A CHANCE!

In spring we'll start pulling out the old lathe & plaster and put in blue or pink rigid board and spray foam edges.
i.am.flink5 years ago
The thing about blow-in insulation like cellulose is that you absolutely must remove all of the old insulation. Typically, it's old fiberglass batts with either kraft paper or aluminized backing. The reason for removal is to ensure that there's no buried electrical junction boxes (whether for splices, taps, overhead light/fan in the room below), and to seal any air infiltration points. Use some semi-permanent poles to mark their locations for the future. Air infiltration defeats the insulative properties of whatever material you insulate with. Consider the layout of the floor below. Examine each bit of attic floor that is above a wall. Seal any gaps. Use expanding foam, a piece of sheetrock that you caulk in place, etc. The thing is to stop the warm, moist air from entering your attic. Carefully build an aluminum flashing box around the chimney. You must keep insulation at least three inches from the chimney. You can seal the top edges with fireblocking expanding foam (I think Dap's is in a green and orange can. It'll be distinctive and definitely say "Fire Blocking" on it.) Check for plumbing and HVAC chases. Seal any openings. Stop that warm air from leaving the heated envelope of the house and the moisture it brings with it. When you've sealed the air gaps, and if your ceiling does not already have a layer of plastic vapor barrier between the sheetrock and the joists, use tuck tape to seal a sheet in every joist bay. That will stop moisture from migrating through the sheetrock. Moisture is your enemy. That's what causes mold on the roof decking and rafters. Some say that the semi-permeable barrier of the ceiling's latex paint is sufficient. IMHO, I don't think so. It's a little more work, but not having to worry about moisture freezing to the underside of the roofdeck is nice. See where your roof vents are. You might have grilled windows or openings at each gable end, or a vent cut into the peak of your roof, vents at the soffit area (under the eaves of the roof). It's important that you let the air flow through these. They help flush moisture from the attic year round as well as moderate the house temp in the summertime. You can staple air baffles into each rafter bay if you have soffit venting. It's extremely important not to block that air flow. Once the baffles are in place, blow in cellulose. Honest. It isn't terribly hard, it is only intimidating until you read on it a little. I did 750 sq feet, 16 inches deep in 3.5 hours. Most big box places give you free rental if you buy 20 batts of insulation. I used two pallets for mine (still have 6 batts left). It is definitely a two-person job. One to break the batts into the blower and one to blow the stuff. Both will need respirators and a hat is a good idea, too, as are goggles. It's very dusty. The hardest part was off loading the insulation and horsing the blower (one person can manage it, but it is awkward). If I had to to it over again, I'd do it a few years earlier! My heating bill went down last winter. I spent about $450 on the insulation and all told, about 9 hours running though the steps I described.
Rishnai6 years ago
Just for the sake of going completely off the wall here, if you have access to Polarfleece or similar high-performance, synthetic-insulated garments that have been destroyed somehow or would otherwise be free/cheap per cubic foot, that would be very effective. Can you say make friends with the local pillow factory?

Vaccuum is the best insulator known to man. And know, I don't mean a Hoover, I mean lack of matter. If you don't have critters in the attic, you could build wooden boxes to lay over top of the ceiling joists, sealed with plastic bags, and a fitting that you can attach a vaccuum to, but will otherwise be airtight. Drill through the wood box to the center cavity, so you're sucking the air out of the inside of your carefully built and caulked Gigantic Plywood Box. Suck the air out in December, enjoy vaccuum insulation all winter. You'd probably want to use a thick vinyl, actually, like avoveground pools, not just Hefty bags.

By the way, what did you end up doing last winter?
tourmrl6 years ago
The fire retardant (FR) issue mentioned by zieak is a good point, but can you buy and apply some FR yourself to the styro peanuts? I am familiar with big box drugstore chains, and around xmas season they get in trailerfuls of "inexpensive" gifts - candles in glass, plaster figurines, you know the stuff. They don't want it to break - not until you get it out the door, that is - so it comes packed in cheap cardboard and styro. For almost two months, they fill their dumpsters to overflowing, literally, with a mountain of the stuff. They can't even get rid of their regular trash because of the volume. So, if someone came up to them and asked them to set aside bagfuls of the styro peanuts, and maybe dropped off a box of donuts and "box of Joe", they might find themselves in possession of more insulation than they know what to do with, and it would only cost them peanuts. ; ) Oh, all right, and a coffee break, too. You would have to see the Manager directly, and they would be wary that none of their merchandise ended up going out the back door, but you can see the potential. Also, you can't completely block all the air circulation in your attic. Vents are built under the roof edges to allow excess heat to escape during the winter. If you totally seal the attic and heat builds up on the underside of the roof, the snow pack can melt on your roof and form ice dams on the edge. This is not territory you want to venture into, unless you enjoy challenging your DIY skills by installing a new roof. So, insulate the ceiling below you when you're in the attic, but beware of totally sealing the attic itself! I bought a 50 yr old house a couple of years ago, and found myself hacking at 2 ft. thick ice dams this past winter. I banged on a crowbar with a sledge, like it was a chisel, to split open cracks in the solid ice and break it up into big chunks. Some of the pieces I knocked off and dodged were as big as a surfboard and heavier than myself! Try a few hours of holding a heavy 2 foot metal bar in one hand while swinging an 8 pound sledge at it with the other, all while atop a tall ladder on ice. Took me 8 hours over three brutally cold days to do. Take it from me, this is more DIY than you want. I'm a rock collector, and I never thought my experience splitting boulders would come in so handy. But, I still have a roof.
Odovacer (author) 6 years ago
Ok, I give. I'll go for the conventional fiberglass rolls. Thanks to all for the comments! -Odo
I have been exactly where you are standing.

Taunton Press put out a book in insulation and weatherproofing. Get a copy of this. The amount of pain it saves you may far outweigh the cover price.
http://store.taunton.com/onlinestore/item/070649.html

I did the blown in insulation and am not experiencing the kind of issues uguy describes, but I'm not promising you anything.
zieak6 years ago
The problem with the foam packing material is the lack of fire retardant. Springing for the fiberglass insulation could save you the full cost in your heating bill this winter alone depending on the amount of insulation you have now and where you live and what you use for heat. Seal all potential air leaks with expanding foam , caulk, or whatever will suit the job too.
Patrik6 years ago
Let's see... a 40 sq ft roll of fiberglass is about $10 at Home depot. 1000 sq ft = $250.

I think you may have a hard time coming up with something that can compete with that, for the amount of surface area you need to cover.
Goodhart6 years ago
Whatever you use, trap the air in the attack, but try NOT to trap the air from below the attic (your living area). That can lead to dire consequences.
NachoMahma6 years ago
. I have put an old nylon on the end of the dryer vent and let it warm/humidify the house, but don't think I'd try it in the attic. Too much condensation.
uguy6 years ago
Dryer vent is a bad idea, moisture in vented air would do much harm. I did the DIY blown in cellulose a few years back and have regretted it ever since. Dust level in the house is terrible and impossible to control now.
srikar066 years ago
moisture trapped beneath anything in a house is a bad idea. its a perfect recipe for mildew and mold (we had this problem once). if you have lot of annoying geese, go geese hunting and use their down :). i think we use fiber glass in our attic. one thing i do know is that you want something that lets moisture move freely but traps air. (imagine fluffy pillow stuff).
Kiteman6 years ago
As Goodhart says, you need to trap air. My grandmother had her loft filled with newspaper that had been "fluffed" somehow - it was in tiny pieces, only a letter per piece and all fluffy round the edges. That strikes me as a fire-hazard, though. Don't forget insulation by reflection - one of the most cost-effective insulators is aluminium foil. Putting a layer of foil behind each radiator in the house costs around $5, but will save that cost in reduced heating bills within a year (most insulators take 5-10 years to repay their cost in reduced bills, at which point the most expensive ones (such as uPVC double glazing) will need replacing anyway, putting you back to square one).
Goodhart6 years ago
One of the best insulators is air, that is, trapped air. This is why fiberglass enclosed in paper works as well as it does, or double paned windows.