attic insulation - where to start

[thricesplice]

We just bought an house mid-century modern house at a great price; problem is that the insulation needs work.  Previous owner had winter combined energy bills of $200-400 /month.
House is a ranch, approx 2000 sqft.  Attic is accessible but but you have to crawl around on your knees as their is not enough ceiling height to stand in.  Currently there is some insulation present; looks like blown fiberglass or a previous iteration of that; about 5 inches.  House has several skylights, as well as a high velocity AC system (e.g. holes in the celing leading to ~2 in OD ducts that supply the house with AC).  Soffits ont he side of the house have small ventilation holes everyonce in a while.  House has two chimneys which we occasionally use.  House also has one corner side of the house that is almost entirely made of glass; most but not all of the windows are double panel; it looks gorgeous but looses heat easily.  House has in-floor hydronic heating; heated water pipes going throughout the concrete slab; thus ductwork is not used for heating.

I'm looking for advice on how to most price effectively insulate the attic.  I only somewhat understand the theory behind insulation; i get the basics but don't know very advanced specifics (what R value to use, types of insulation, cost effectiveness of repairs, or anything about roof materials for that matter).
Also FYI, i have access to unlimited free silicone caulk ( I have sealed up the basement fairly tight so far.

[iamsoners]

I'd blow in a ton of insulation into the attic and do your best to seal the ceiling up from below around the windows and light fixtures and such.  Also check with your local utility to see if there's an energy audit program available.

[Greg]

Accessibility will make it difficult, but you would best protect the soffit vents from insulation blockage and blow in more.  In my area fiberglass is still the most common for blow-in by pros.  How much?  pretty much as much as you can, R-30 or better.

First do as soners says and air seal.  Also, wrap skylight wells before blowing in more.

About that soffit venting, where does the attic venting air coming in exit at the top?

[thricesplice]

Yes, the air enters through the soffit vents and exist through a small vent lining the top of the roof.

We had an energy company come and evaluate, but they were just some standard contractors trying to sell us stuff we didn't necessarily need based on a super high cost.  Anyways, they wanted to expand the vents and add more of them.

[monarda]

+1 on getting a real energy audit and air sealing.

you can start with this DIY version to get an idea of more trouble spots

Do you put plastic over the windows in the winter?
That's a cheap fix to try one winter and see how much of a difference it makes.

[Daleth]

I've been looking into wool insulation. Apparently it comes in batts or in loose fill that you can lay down, and it has a bunch of advantages over other types:

- Very easy to DIY (same equipment you would need for fiberglass batts, but it's non-irritating to skin and lungs so you don't need protective gear)

- Excellent insulator

- Naturally fire resistant (basically there's not enough oxygen in this planet's atmosphere for wool to easily catch fire), and what's on the market is treated with borax or similarly harmless substances that make it even more fire-resistant and pet resistant

- Not affected by water; wool is naturally crimped/frizzy, so if it gets wet, it's not (unlike most insulation) destroyed. You just dry it off or wait for it to dry and it bounces right back to its original shape--meaning the insulation puffs back up to its original thickness

[thurston howell iv]

A few years ago I was looking to replace some of the cheap, flimsy insulation in my walkout basement. One wall was insulated wood stud construction with the other 3 made of block. I tried the cheaper diy stuff but decided that I needed a little more. I priced several options and settled on spray foam- not the cheap stuff in can but, the heavy duty guys with hoses blowing it in.  That stuff was amazing! (place sealed up like an igloo cooler)  It was relatively cheap and iirc, I think it may have qualified for some tax benefits as well. 

Just for a point of reference, this is the place I used:http://www.epiphanyfoam.com/

http://www.youtube.com/watch?v=z1fbLtyeLfU

note: first link was taking too long to load so I found a youtube sample as well.

It worked great for me and I recall seeing the foam treatment in many new constructions down in FL some years ago.
In my next home, I will be looking at foam first!

[GodlessCommie]

Before you put more insulation in the attic, make sure to air-seal it (yes, air-seal the attic). Leave soffits alone of course. Amaizing amount of air (judging by the amount of dirt in insulation) goes around top plates, electric and plumbing penetrations, and such. Here is a good guide: http://www.greenbuildingadvisor.com/blogs/dept/musings/air-sealing-attic . I highly recommend this site in general.

The reason you want to air-seal before is that you will have less fluff to dig through to get to all the gaping holes that I'm sure you will discover. It is a pretty unpleasant work, but not very physically demanding. Bending in some funny ways while trying not to step on drywall is probably the biggest challenge. Nice side effect is that it is very cheap: just caulk, foam, and scraps of plywood, or even cardboard.

On blowing insulation - hauling that machine from Lowes or Home Depot is not as hard as it looks, and operating it is even easier. You want to get a good respirator (it will get dusty as hell), and cover attic access hatch well around the pipe, too. My wife and older son were feeding the cellulose, and I was in the attic. We used walkie-talkies to communicate, and were done in less than a day.

It is a very Mustachian thing to do - you spend little, do some honest work, and feel great afterwards (after a shower that is). 

[kimmarg]

Energy audit is well worth it. While your attic doesn't sound great there may be better bang for your buck elsewhere. We paid about $200 to have one done. It was worth it because it showed us what we needed to work on (some of which was easy to do ourselves) and also qualified us for a $600 insulation incentive from the state. We ended up matching the states $600 and paying a contractor $1200 to blow in insulation in our crawl space. Yes, those DIY machines apparently aren't that hard but the panic attack claustrophobic me would have in our very small crawl spac made it money well spent. They air sealed before they blew stuff in as well. So far our energy use seems to be down about 10%

If you have n floor radiant heat definitely look into solar heat. You get collectors on the roof that heat the water and then only fire your oil/gas furnace when the sun doesn't do it. Even in northern New England we get enough sun for this. (Plus our high energy costs speed up the payback) google residential solar thermal heat.

[TomTX]

1) Get a 2-3 chunks of scrap plywood big enough to kneel on (and span between joists) NOT full sheets.

2) Get some kneepads and gloves.

3) Get a couple of cans of foam sealant.

4) Go up in the attic and seal EVERY penetration (hole, crack, whatever) between the attic and the inside of your house. Move the plywood around so that you have something to kneel on while you foam the penetrations. DO NOT block any penetrations between the attic and outside. Go buy more sealant as needed ;)

5) Once EVERY hole is sealed, you can think about improving soffit and roof ventilation.

6) Once you are happy with the ventilation, you can think about insulation. You definitely need more than 5" of insulation, and you need it to be a full layer. Don't leave low spots!

[Blindsquirrel]

 Where do you live is a reasonable question? The US dept of energy  has good info at

http://energy.gov/public-services/homes/home-weatherization/insulation

  For northern climates, R38 or so is the recommendation as I recall. We insulated the bejezuz out of our attic when the government had tax credits for insulation. Your state and utility co may also have a deal. We cut propane use from 900 gallons a winter to about 400 and change. The attic is all about R60. 38% of your average homes heat loss is through the attic. Blown in cellulose is probably cheapest and not a hard DIY at all. Craigslist is a good place to get a few bales of insulation here and there also.

[TomTX]

Cellulose is also better insulation (higher R-value per inch) than fiberglass.

Frankly, other than big corporate marketing and the convenience of batts (where applicable) - fiberglass sucks. Packed cellulose in between wall studs has a much higher R-value, reduces air penetration and helps more with sound dampening.

[Cromacster]

Reporting back now that I just finished insulating my own attic.

Good Project, glad I did it, pain in the ass though.  This is mostly due to the fact that I have finished space in my attic.  Most of the time was spent air sealing the top plate of the walls, light fixtures, and every other penetration (5 hrs) and installing foam blocks in between the joists where the knee wall meets the attic floor (9 hrs).  The second longest part was installing the baffles (vent channels) along the soffit vents and in the slant wall up to the peak attic (7 hrs).  I also installed a second layer of insulation batts along the knee wall (5 hrs).  The quickest part of the project was blowing the insulation (3 hrs).  Completed over 2.5 days.

Projects that I still have left to complete: Weather strip and insulate 3 access doors and foam block and air seal basement rim joist, complete bathroom exhuast fan when winter ends (need to cut hole in roof for vent)

Total cellulose that I blew in was 18" in the side attics.  In the peak attic I blew in 10".

So far it looks as though I spent around 2k, but I need to separate out some items that I bought for another project (bathroom fan) to get my real total.  If I separate out the tools and safety gear purchased that can be used for other projects the costs goes a little lower as well.

This project would have been much simpler if I did not have finished space in my attic.  I could have probably done this project in a day if this was the case.

Oh and cellulose blower rental was free from Home Depot if you purchase 20 bales of insulation.  I ended up using 50 some.  Do your own math.  The manufacturer website claimed I would need around 120 bales to achieve my desired R value (R50).  I bought 100, and ended up returning around half.  I still achieved the required depth for the R value.  I will have to check back in a few months to see if there has been any settling.  But from here on out if I need to blow more in, it will be a cake walk compared to what I have done already.

Edit:  Oh and wear some latex or plastic gloves and using cans of expanding foam.  I've never really used the stuff so I ignored the warnings on the can.  The stuff won't come off your hands for a few days.  The can says once cured it only comes off by mechanical means, so picking away and losing skin, or just waiting.  Lesson Learned :)

[Greg]

Good job, I know it's a lot of work, which is why I often sub it out on my design/build projects.  Did you go with fiberglass or cellulose?

The foam stuff is pretty sticky stuff.  I hate getting it on my skin or worse, clothes... it never comes out of clothes. 

[Cromacster]

I went with the cellulose insulation.  Was a snap to blown in once all the prep work was done.  I will have saved about 1600 once I complete the access doors and basement rim joists.  So in the nature of this forum I am glad I did the work myself and saved the money.  I feel very accomplished.  Would I do it again? Tough Call, not if it was another 1 1/2 story haha.

Yea I got that foam all over my pants, they are my "contractor" pants though so they are supposed to get dirty.  Hard to avoid it when you are spraying foam and crawling around in the attic.

[ManyMountains]

So, I am looking to do the same thing with my attic. I have a 1200 sq ft home, built in the 1960s, located near Sacramento, CA - hot summers and cool (but not Minnesota cold) winters). It currently has about 5" of blown insulation. So thank you all for the advice.

I'll take all of the initial steps to seal the house/attic as outlined above, and then consider getting the insulation and blower from Home Depot. However, I am only finding two types of blown-in insulation on HD's website: fiberglass, and recycled denim cellulose. Is the latter what you would recommend? Or is there something else I should look for?

Thanks!

[Greg]

Websites don't always show what's available locally.  Best is to check with the store near you, even by phone.

[TomTX]

Yeah, check the local store - but if you have a denim plant in your area, that would be a cheap source for the raw materials used to make the insulation (basically pulp the scrap, treat with borax) and would explain why the cellulose option is denim. Around here, denim is more expensive than regular cellulose insulation.

[Cromacster]

http://www.homedepot.com/p/GreenFiber-Blow-In-Natural-Fiber-Insulation-INS541LD/100318635?N=bayp#

For some reason it's not the easiest to find when searching for insulation on HD's website.  Here is the stuff that I used.  Its much cheaper than the denim insulation.  Made from recycled newspaper.

[ManyMountains]

Fantastic. Thank you all for the help!

[puglogic]

Cromacster, did you use something like this for your soffit vents:
http://www.homedepot.com/p/Amerimax-Home-Products-41-in-x-22-in-Accuvent-Vinyl-Attic-Airway-and-Soffit-Vent-in-Black-ACCUVENT/202962730#

I admit I am having trouble picturing how to put these up but I know it will come to me when I can hold it in my hands. We really need something as a barrier for the soffit vents, because we're going to be blowing in a LOT of cellulose.  Are these useful?

[Cromacster]

Yep, I used these.

http://www.homedepot.com/p/ADO-Products-14-in-x-48-in-Attic-Ventilation-Channel-10-Per-Carton-UPV1448010/202541345#

Useful? Yes.  Needed? Absolutely.  If you are blowing insulation these prevent your soffits from becoming blocked from the insulation.  A blocked soffit vent means no airflow, which means ice dams.  If I did not have these the insulation would have filled in over the vents (I blew in 15 in or so).  They fit in between each rafter/truss/stud whatever the correct term. 

[Daleth]

For anyone interested, here are some links where you can read about and/or buy wool insulation:

http://www.oregonshepherd.com/

http://www.goodshepherdwool.com/

http://www.sheepwoolinsulation.com/

http://evanandgabbystinyhouse.wordpress.com/3-the-concept-of-using-natural-wool-insulation/ (blog about eco-friendly renovation of a tiny house; they discuss their experience with wool insulation from Oregon Shepherd, the first link above)

http://www.thermafleece.com/