Attic insulation - Questions..

[r0GuE]

I have a 50ish year old ranch with rock wool insulation. The best I can tell is that rock wool is nothing but fiberglass. The insulation has a vapor barrier (where it is intact) and it seems to be installed right based on the instructions printed on its paper backing. It is perhaps 3 to 5 inches thick and pretty matted down and torn up from wiring additions and changes over the last half century.

I am now planning on adding enough insulation to reach closer to the recommended amount for my area. I am thinking I need R-40ish. I believe what I have is probably about R-9. I have decided that since there are so many nooks and cranny’s in my attic, I had better use blown in.

I am debating fiberglass and the Cocoon brand cellulose style. The fiberglass type uses a bigger blower which I will not be able to get in to my attic. The people at Lowe’s said that it only has a 50 foot hose, so I don’t know how can work around that. I would probably need closer to 100 foot of hose for me to be able to leave the blower outside. The Cocoon brand blower I could probably get in to my attic, but I am worried about it getting damp and then molding. I have a tile roof and if the wind blow’s right, some water gets in.

Anybody have experience blowing in insulation? What type? How long was the hose. Any problems recommendations or advice?

Thanks all!

 

[Durbob]

I built houses for 19 years and we always used blown in cellulose insulation with no problems. We set the machine in the garage and had a hose long enough to reach where we wanted. The nice thing about cellulose is that it didn't lose its R-value when it settled. It took a lot more fiberglass insulation to get the same R-value. This is in southern ohio. Your mileage may vary.

 

[dieselsmoke1]

Blown in cellulose is pretty much the standard here. Mine got soaked when hurricane Floyd came thru to the point there was water dripping out the light fixtures. Dried out in a few days with no apparent side effects.

 

[Bird]

Rogue, when we built my brother's house, he bought the insulation and borrowed the blower from Lowe's and like you said, they told him it only came with a 50' hose, which wasn't enough. They didn't want to do it, but when they realized they were going to lose the sale otherwise, they gave us the hoses off two machines and hooked together worked just fine.

 

[TimSullivan]

I owned a company that installed insulation and I would agree that cellulose is the way to go. As for the Lowes’ machines, check the blower capacity. The ones they have around here are real small units. Check with the construction rental outlets in your area for bigger faster units. Then you can add as much hose as you want without the loss of production time.

In commercial contracts we sometimes used three hundred foot of hose but you need to have the blower power. It is a dusty and dirty job and the small machines make it much worse. I don’t know how much you are going to send through the machine but my neighbor spent all day doing his rancher with a Lowes machine. It should have taken a couple of hours.

Install a baffle on the inside of the vent to keep the water out. With mold as a big issue today you don’t want any extra moisture in the attic space.

Have fun and wear good breathing protection in the attic and also for the loader at the machine. If it is cool enough wear something like a rain suit to shed the cellulose. I still have a few coveralls with hoods left from the company that are nylon and the cellulose just falls off.

Lay out some planks across the attic for a walk way. It will make the job easier and safer too. Not good to put you foot through the living room ceiling. Since it is your house just leave them in place to make access easier later.

Have fun moon walking.

 

[fishman]

Let me preface this by saying I've only blown in insulation twice, but it isn't that hard.

We used the "free" blower from the lumberyard and it worked fine. Leaving it outside saved a lot of work.

It is at least a two person job, three is better. One to break up the cellulose bales, one to load the machine, and one to blow the insulation. Have two 35 gallon trash barrels available. One person breaks up the cellulose into small chunks. Another takes the trash barrel and slowly pours it into the hopper while the third person blows the stuff around in the attic.

If you only have two people, the guy in the attic is only blowing about 2/3 of the time.

 

[Bird]

Tim, since the machine from Lowe's is the only one I've ever used, I don't know anything about the differences, but on my brother's house the attic access door was in the ceiling of the garage at one end of the house and we just backed his pickup into the garage with the blower and the bales of insulation in the bed. He got up in the attic and did the blowing while I did the bale bustin' and loadin' into the blower and it didn't take us more than two hours to do the job. It was blowing that stuff through 100' of hose as fast as I could load it in the hopper.

 

[Chuck52]

Do you need to worry about your soffit vents? Seems like there are products to put over the vents to keep a free path for them. I have a shallow pitch, hipped roof, and when I get around to doing this job I know keeping those vents free is going to be one of the major pains.

Chuck

 

[r0GuE]

Very true. I will be blocking up the ends to keep the soffit clear of blown in insulation. I also have to take care to keep insulation away from the recessed lights (16 of them.)
And I also want to retain access to any and all junction boxes in the attic. So I have my work cut out for me!

 

[Bird]

Good point, Chuck, but something we didn't have to worry about. My brother designed and built his house himself; very simple straight line roof with gables at either end and vents in the gables; no soffit vents.