BTW, spray in is @ 10 inch thickness, and in my opinion, a better product then blanket insulation. Fills more air voids

Not rodent infested, just old, squished in areas, and probably has seen water due to the many holes in my 33 year old wood shake roof (which I am also replacing).

The key here is the wood shake replacement. When the shakes are removed, much litter will fall into the attic. Been there, done that. Cleaning it out afterward is a *really* good idea. Dead bugs, wood shake splinters, bits of moss, leaves and nails all appear. Then put the new fiberglass batting down. The paper coating makes it easy to pick up and look for the occasional dead rodent or mysterious electrical connection.

I do recommend getting two more estimates. $4600 sounds high to me.

I have blown-in cellulose insulation, professionally installed. It drifts. Every time the wind blows over 20 miles per hour or so, tiny pieces are set adrift. They land on the recessed lighting. I would not use cellulose insulation again in an attic that had any recessed lighting.

There are a couple of determining factors involved. Access and roof pitch. The usual scuttle hole in a 1960's ranch home is about 14'X24". Hard to get into, hard to stuff insulation up through. Roof pitch on the old ranch homes tended to be 4/12..4" vertically for 12" horizontally. So the resultant headroom and space for working is pretty pinched...a 20' wide building rises just 40" at the peak...and then there are all those trusses in the way. Code in California currently calls for R38 in attics...R30 is OK, but not enough! So, let's figure the costs, OK? R30 comes in 24" wide X 48" long batts, 80 s.f. in a bag (currently $72 at HD). You need 25 bags...$1800 plus tax and delivery...call it $2000. To clear out the existing insulation and clean up is two guys, one day. Cost in NorCal is around $25 per hour...but labor burden sends that up to $35 with worker's comp, disability, unemployment, medical (required!) and social security. Then a day to install the new, same two guys. Total of 32 man hours. $1120. Add dump run to get rid of stuff, 3 hours plus dump fees, $120. Factor in supervisory time, 2 hours at $65...$130 Sub total $3370....add 20% for P&O...$674. Grand total $4044.00. Did I miss something in this ballpark figure? Most likely! I'm not there, on site, figuring labor and material...are baffles included to keep the roof vents clear? Is access to the attic through a closet that needs to be cleared out and cleaned up and put back into order? Is site protection, walk off mats, booties, plastic to protect the house from dirt and debris included? Not on my rough estimate! So the contractor is walking with MAX $1000. Probably a lot less. More like my $675. And for that he gets to come back and fix the cracked dry wall and nail pops on the ceiling and repaint it for "free" because one of the guys slipped and put weight on it. Or deal with the can light that keeps going out because the insulation is laying on it and it gets too hot and shuts itself off. Did the contractor fluff it up a bit...probably...it's CYA. But he's not laughing all the way to the bank.

@Yarbro...yes, $1 per sf for new construction. Imagine those hoses strung through the house and into the attic in a furnished and finished home. Hose management alone would be three guys!

Get a few more estimates, and then you will know.

Soberg, I agree with apple-pie-order and Ironwood. Don't insulate prior to new roof (it leaves a huge mess in the attic) and the contractor you got the estimate from is not laughing all the way to the bank. Also, you've now thrown in a new twist. A new roof. For all the reasons mentioned above by Ironwood here is a suggestion, and I've used this approach before... When the roof is torn off, this is now incredibly easy access for the insulation crew for either blow in or blanket and removal of old. No traffic through the house. This will take a little coordination from you, the roofer and insulation contractor ( if the insulation contractors insurance allows this ) and in fact the insulation crew may prefer this and it could save you some $ and hassle. They'll need a access hole through the roof. Easy to cut and easy to repair. 20 minutes. WATCH THE WEATHER FORCAST.

blown in fiberglass type added rectently to insulate up to R-49. $605 for 1400 sq. ft. Wow! $4,600? Glad I live in the midwest!

Thanks for all the great input. Access is definitely restricted as Ironwood indicates. My GC also has 4 rooms of my house pretty well ripped up for my kitchen remodel so the time just feels right. The GC has been getting quotes and got his sub to reduce the bid to $3200 for R30. I accepted that and now will ask him if there's still time to change that to R38 (I would pay the delta of course). For popped nails and Laurel & Hardy-type foot through the ceiling incidents, that will be my GC's problem as the insulation fellow is not licensed to work solo and my GC has agreed to supervise him.

Good job soberg! Sorry it's all torn up, but you are right..now is a good time!

Wow! $1,400 just like that! "Insulation fellow is not licensed to work solo" and yet not a employee of your contractor yet HE, was charging, YOU $4,600 for the insulation work. I didn't want to attack a fellow contractor in my earlier comment, but... Ironwood, you should be annoyed and irritated. This is your region and these are the guys you have to compete against. Sheesh!

That is very high. I can have a 2500.00 ft. house done with formaldahyde free batts for less than 3k inlcuding floors and privacy walls at bedrooms and bathrooms. Seattle is less expesive than the bay area, but not that much.