Home maintenance stoke: Anyone blown their own insulation?

[DJSapp]

...and if you've blown your own insulation, how do you get the fiberglass out of your mouth?

Looking at doing something to keep the cool air in and stop paying $250+ in power/month during the summer when it's 105 outside. 1250 sqft house, 4:1 pitch roof, so it isn't exactly an easy space to access, but it's not a large area either. about 4.5' from top of joists to peak of roof. Existing insulation is fiberglass bats, 4-6" of thickness there. Various eve vents to be blocked out as well.

Looks like I could get the materials and blower rented for under $1000 according to HD and Lowes calculators.

Is this a big hassle to do, or a 4 hour cakewalk? Getting some prices from some contractors as well to see what they can do. I hate getting up into the attic and it's a pain to get around, but I'll work to save $100/hour.

[Jacques Sheer-Rocko]

It's hot and messy but easy. Use some boards to span joists and give a less uncomfortable place to stand/kneel/crouch. Also, before blowing, staple up some of the formed styrofoamy things in the eaves to maintain ventilation.

[riser4]

...and if you've blown your own insulation, how do you get the fiberglass out of your mouth?

You're doing it wrong.

[Beaver]

Easy, but you missed the fucking boat for this year unless you really want to sweat like a motherfucker and hate every minute of it. I did mine in the spring a few years ago while it was still cool outside and it was still a hot job, 1500sf took about 3 hours of actual in the attic time. You'll need someone to feed the hopper and someone to make sure he doesn't run out of insulation to feed, it sucks when you're sitting in the attic with nothing blowing out the hose. A few boards make it easier to not fuck up your drywall, just leave them behind. Knee pads will be your friend.

I was in my attic about a month ago for 10 minutes doing some electrical and it fucking sucked, it was about 120 degrees up there and only about 70 outside.

Edit to add: Before you start smoke a big fat doobie.

[MagnificentUnicorn]

...and if you've blown your own insulation, how do you get the fiberglass out of your mouth?

Looking at doing something to keep the cool air in and stop paying $250+ in power/month during the summer when it's 105 outside. 1250 sqft house, 4:1 pitch roof, so it isn't exactly an easy space to access, but it's not a large area either. about 4.5' from top of joists to peak of roof. Existing insulation is fiberglass bats, 4-6" of thickness there. Various eve vents to be blocked out as well.

Looks like I could get the materials and blower rented for under $1000 according to HD and Lowes calculators.

Is this a big hassle to do, or a 4 hour cakewalk? Getting some prices from some contractors as well to see what they can do. I hate getting up into the attic and it's a pain to get around, but I'll work to save $100/hour.

Move somewhere where electricity is cheaper?

[XXX-er]

I did blow in myself, upgraded to a HE furnace, between the 2 it cut my equal payment gas bill from 220 $ a month to about 110$, with federal & provincail energy incentives paid about half of the 6K it cost me and the savings on gas paid it off in <3 yrs but its way better heat, way better control, I can just leave for a month and the furnace runs for the tennants when it should

its its a shitty fucking job so if you can make money doing something else/maybe OT at work and pay some poor bastard to go up there consider that but as a lowly pensioner with noting to do but be an asshole on TGR ... the DIY seemed like a good idea.

you want tyvek coveralls, gloves, seal gaps with ductape, a better than cheapest breathing mask and a hockey helmet for personel protection

you go up there and measure what you got , I think I had 6" of pink insulation, so I wanted R50 so figure out how much to blow in (I think it was 18") and mark your joists with a felt pen so you know how high to blow, then you need to put in foam soffit baffles to keep air circ even when you have 20" of insulation in the edges of your attic

Now is the time to upgrade attic ventilation if you need it , not only does it prevent your roof rotting it can make a house considerably cooler in summer, also you gotta build up the box around the openning of the attic to 24" or so, also you gotta build up the area around the furnace & water heater vents, they will get hot so you don't want insulation touching them, you gotta make the hatch cover R50 which I did using 3" blue styrafoam

All this^^ took a few days so do it all ahead of time before you do the actual blow job

The local lumber yard gave free use of the blower when you buy the bales of insul, you need a hopper bitch to load the blower, my buddy was the hopper bitch for me and i was the hopper bitch for his garage project, the actual blowing of the insul takes a few hrs for a 1000sq' house and its dirty but pretty easy, at this point I would wait till the fall when its cooler to work in an attic

[DJSapp]

Would I need to worry about keeping the bottom of the roof clear for some breathing space? I'm looking to go to R60 and with the low clearance in there, 18" of insulation above the joists is going to be over a third of my attic packed ceiling to roof with fluff. Or is this not something to worry about because it will settle out?

[::: :::]

you do need to worry about venting your attic...make sure you're not creating blockages

the installer who did ours stapled cardboard (or plastic) panels to the bottoms of the 2x4 rafters at the low end of the roof to preserve an air space that connected to the covered eave. the panels reached up high enough to provide a 6" buffer from the top of the blow-in

[MagnificentUnicorn]

Seriously, I think in your situation with the low slope roof you don't want a thick layer of blown in insulation.

[::: :::]

especially with a low slope roof (3:12 to 5:12), realize that the triangle shape of your roof is not allowing the R60 to be fully effective so it might be a better value to consider R49 knowing that the low ends where the top of your wall connects to the attic is short circuiting the high value anyway. this obviously depends on the width of your house. and, if you're getting credits for the R-60 or something, then ignore me...

[DJSapp]

you do need to worry about venting your attic...make sure you're not creating blockages

the installer who did ours stapled cardboard (or plastic) panels to the bottoms of the 2x4 rafters at the low end of the roof to preserve an air space that connected to the covered eave. the panels reached up high enough to provide a 6" buffer from the top of the blow-in

I get that, and I can staple panels up the rafters from the vents. I'm asking about the eves that don't have vents, they'll be stuffed full of insulation for ~8' from the eve to the point where the roof is higher than the depth of the insulation. Is that kosher? It's a small attic, so it's going to add up to a large percentage of my total area.

[::: :::]

anywhere you don't have direct ventilation is susceptible to condensation on the underside of your roof decking

are the existing vents in the plane of the rafters?
(like holes cut into 2x4 blocking at the perimeter of the attic directly above the exterior wall)

or, do you have an exterior horizontal soffit beneath the rafter tails?

(if you have a traditional stick built house, your edge may be thinner than the one shown below)

[Below Zero]

I get that, and I can staple panels up the rafters from the vents. I'm asking about the eves that don't have vents, they'll be stuffed full of insulation for ~8' from the eve to the point where the roof is higher than the depth of the insulation. Is that kosher? It's a small attic, so it's going to add up to a large percentage of my total area.

I'm assuming you are in a cold weather climate: Zone 5 or 6. You need to install eave vents: the more the better. Leave a 2" gap between the bottom of the roof sheathing and the insulation baffles (carboard is fine). Install the insulation baffles between each truss (assuming you have trusses) bay. Make sure the baffles extend at least a foot past the top of the blown insulation; this prevents wind washing. Make sure you have exhaust ventilation via a ridge vent of pop-up vents. Pop-up vents should on be on one side of the ridge, preferably the leeward side. The "size" (technically net free air flow; I want go into all the calcs of air flow) of the exhaust ventilation should, preferabbly equal the intake. This all assumes a basic gable roof; multiple ridge lines make it more complicated.

Once all that is done, air seal with a one-component spray foam (you can buy them at Home dept) all the penetrations in the ceiling plan.

I would recommend blowing cellulose instead of fiberglass.

If you stuff the eaves with insulation without providing intake ventilation, you may experience ice damming issues at the eaves.

This quick and dirty advice; there may be other variables to consider (for example, if you have a masonry chimney that penetrations the attic)

[Below Zero]

Good visual by acinpdx. If you don't want to hire a professional to look at the building science and building details of your project, you could just go buy the book that acinpdx posted: "Builder's Guide to Cold Climates"

[KQ]

Now is the time to upgrade attic ventilation if you need it , not only does it prevent your roof rotting it can make a house considerably cooler in summer, also you gotta build up the box around the openning of the attic to 24" or so, also you gotta build up the area around the furnace & water heater vents, they will get hot so you don't want insulation touching them, you gotta make the hatch cover R50 which I did using 3" blue styrafoam

All this^^ took a few days so do it all ahead of time before you do the actual blow job

And to make sure all your electrical is up to snuff. I had my insulation professionally done so I can't speak to the DYI aspect of that but prior to the insulation guys showing I had my electrician up there checking all the wires/cables/can lights.

[::: :::]

Good visual by acinpdx. If you don't want to hire a professional to look at the building science and building details of your project, you could just go buy the book that acinpdx posted: "Builder's Guide to Cold Climates"

that was taken from the Mixed Climate book

DJSapp, you are Bay Area, right?

[Below Zero]

that was taken from the Mixed Climate book

DJSapp, you are Bay Area, right?

OK. Yeah, Joe uses the same details throughout his books. If your in SF, then your climate zone 3, and no need to worry about ice damming (although you still want to install baffles) and eave venting for attic air flow.

[XXX-er]

I had the house inspected when i bought it, unless you wana make an upgrade at this time if everything works I dunno what an electrician is gona do if but look at the wiring and say ya its all there ... write you a bill ?

My house is a rectangular box with the usual slope so it was a pretty easy job really, if you got a more funky situ it may be better to hire someone and make money doing what you do best to pay for it

it may be smart to get an estimate so you could figure out how much insul product & foam soffit bafffles your house needs and how much will be labor and decide if you really wana itch for 4 days apres job?

I think my materials costs for a 1000SQ' easy DIY on a 30yr old house were 700ish $

[KQ]

I had the house inspected when i bought it, unless you wana make an upgrade at this time if everything works I dunno what an electrician is gona do if but look at the wiring and say ya its all there ... write you a bill ?

In my case it is an older home and there was an issue with rodents that got in during a roof/siding remodel. I don't like going back to do things after the fact and I have a bit of a house fire phobia. As it turns out, there were some issues that needed to be corrected. Nothing huge but now it's done and I have peace of mind. One less thing to worry about.

Something to think about.

[DJSapp]

Some answers:

1. Sacramento area. Ice is not a thing here, high heat is, and we got it in spades. I believe zone 3 is correct.
2. The roof has some eve vents, but they are not continuous like your picture. They're ~16"x3" mesh probably every 4th rafter or so, vertical with the wall butting up to the bottom of the roof plywood.

More like this:


But with a rectangular mesh hole instead. Whirlybirds on the roof and a solar powered attic fan as well.

3. Great pic acinpdx, I could just staple up that blocking continuous across all the rafters and make the venting work by starting the staple job on the stud wall header and going up to the rafters.
4. Attic is a super funky shape, think more like this:



One square worth is the garage, two separate attic accesses.

5. Definitely getting contractors to price this. It's supposed to be 105 today, which means my attic will be at least 140. If I'm not saving $100/hour of work, I'm outsourcing this job.

[XXX-er]

Yeah I waited till the fall and it was freezing at night before I went in my attic, it gets very hot up there

I got aluminium siding which may be cheesy as hell in some peoples eyes but pretty fucking bomber ... I'd rather ski bike paddle than paint or do home maintenance

[The Tortoise]

All this^^ took a few days so do it all ahead of time before you do the actual blow job

[::: :::]

Some answers:

1. Sacramento area. Ice is not a thing here, high heat is, and we got it in spades. I believe zone 3 is correct.
2. The roof has some eve vents, but they are not continuous like your picture. They're ~16"x3" mesh probably every 4th rafter or so, vertical with the wall butting up to the bottom of the roof plywood.

More like this:


But with a rectangular mesh hole instead. Whirlybirds on the roof and a solar powered attic fan as well.

3. Great pic acinpdx, I could just staple up that blocking continuous across all the rafters and make the venting work by starting the staple job on the stud wall header and going up to the rafters.
4. Attic is a super funky shape, think more like this:



One square worth is the garage, two separate attic accesses.

5. Definitely getting contractors to price this. It's supposed to be 105 today, which means my attic will be at least 140. If I'm not saving $100/hour of work, I'm outsourcing this job.

you should drill each rafter bay

old houses could get away with fewer vent holes because the attics weren't packed with insulation, but since you are doing just that, you need to provide air flow in each bay

one thing you can do to improve the insulation at the low corner is to make U-shapes out of the cardboard so that the insulation actually reaches the top of the exterior wall. if you wall off the whole rafter space all the way to the low corner, there's a gap left where you really have zero insulation at the top of the exterior wall.

for improved insul at the corner, maybe even consider 2" rigid panels for that zone? cut tight to fit and tape or string at the underside of the rafter would leave 1.5" gap for air under the decking...just a thought


i'm guessing where the roof turns corners will just have to be blocked since the corner rafter will block out any continuous gap, so if you get venting everywhere except the two bays nearest the building corners, then you're probably doing it as best you can

[XXX-er]

should i fuck off now or wait for you?

[The Tortoise]

Uh, what?