batt insulation and blown in

langless28 · 11-01-2012, 10:19 AM

i am redoing my kitchen. i pushed back the blown in insulation in the attic above the kitchen to redo sheetrock, add recessed lights etc. i will be putting up faced batt insulation and was wondering if its a good idea to rake/blow the blown in insulation back on top afterwards. specifically fill in the areas right around all the recessed lights (total 7) they are 5" halo's and are IC rated and the blown in is of the recycled newspaper/fire retardant type stuff.

**Gary in WA** · 11-04-2012, 06:41 PM

Heavy cellulose insulation will compress the lighter f.g. batts, expect some loss of R-value; http://www.greenbuildingadvisor.com/...fiberglass.JPG

Gary

Windows on Wash · 11-04-2012, 08:10 PM

You will get some compression but you gotta cover those rafters and the cellulose is better are resisting convection.

Make sure the cans are sealed up tight and not just IC rated.

langless28 · 11-04-2012, 08:56 PM

Thanks for the responses. I actually read some older posts stating the weight differences.

Do they make r30 faced rolls of insulation? I was looking at the two big box stores and it seems that faced r30 is only sold in the precut (more expensive) variety.

Fix'n it · 11-04-2012, 09:24 PM

why are you using batts ? and not just blowing more cellulose ?

langless28 · 11-04-2012, 09:32 PM

Well to be honesty don't know much about insulation. Trying to do my best with research. Is blown in far superior? What would be the vb? Plastic sheet under joists?

Fix'n it · 11-04-2012, 10:01 PM

Quote:

Originally Posted by langless28

Is blown in far superior?

What would be the vb? Plastic sheet under joists?

i was told it was.

i was told it isn't needed. and that the paint is all that is needed.

but, i am sure there is more to it than that. so wait for the pros to chime in.

**Gary in WA** · 11-04-2012, 10:38 PM

You pretty much covered it! To back-up the claims; http://michaelbluejay.com/electricity/insulation.html

http://www.cellulose.org/HomeOwners/...orBarriers.php

Cellulose ceiling sag; http://www.energyguide.com/library/E...SubjectID=8375

Check with local AHJ for required poly with your State Energy Code; http://www.ecohomemagazine.com/energ...rfriendly=true

Gary

Fix'n it · 11-04-2012, 11:37 PM

1 thing i noticed with the blown cellulose = it gets in the nooks and crannies. i mean, it REALLY gets in there ! and the pro's here feel this to be a very good thing.

langless28 · 11-06-2012, 07:40 AM

any rough idea on how much a blower would be? i wouldn't not need enough to get the free blower deal. the ceiling is about 100sqft.

also on something like this:
http://www.homedepot.com/Building-Ma...specifications

does that imply it gives a 40sqft area a r3.7? so if i have a 100sqft and want R38 i would need roughly 25 bags of that?

Windows on Wash · 11-06-2012, 09:16 PM

Why not blow the whole attic?

Might as well upgrade the insulation in total.

Be sure to air seal first.

langless28 · 11-06-2012, 09:44 PM

Quote:

Originally Posted by Windows on Wash

Why not blow the whole attic?

Might as well upgrade the insulation in total.

Be sure to air seal first.

It already has been updated with cellulose and air sealing. I had an energy audit and took advantage of a $2k rebate and got air sealing, r38 cellulose and blown in wall insulation for about $500 out of pocket. Unfortunately I am doing the kitchen now, I opened the rafters one by one to blow the cellulose back fom the kitchen area. There was also old batt insulation previously in the attic

Windows on Wash · 11-06-2012, 09:46 PM

Bump it up to R-50.

Can't hurt.

langless28 · 11-06-2012, 09:54 PM

Agreed. As to my question on blown in; is that how's it's calculated?

Fix'n it · 11-06-2012, 09:55 PM

100sf. i think i would put roxul. then pile on what cellulose you have over the top.

11-01-2012, 10:19 AM	#1
langless28 Member Join Date: Nov 2011 Location: MA Posts: 154	batt insulation and blown in i am redoing my kitchen. i pushed back the blown in insulation in the attic above the kitchen to redo sheetrock, add recessed lights etc. i will be putting up faced batt insulation and was wondering if its a good idea to rake/blow the blown in insulation back on top afterwards. specifically fill in the areas right around all the recessed lights (total 7) they are 5" halo's and are IC rated and the blown in is of the recycled newspaper/fire retardant type stuff.

11-04-2012, 06:41 PM	#2
Gary in WA Moderator Join Date: Mar 2009 Posts: 8,851	batt insulation and blown in Heavy cellulose insulation will compress the lighter f.g. batts, expect some loss of R-value; http://www.greenbuildingadvisor.com/...fiberglass.JPG Gary __________________ Clothes taking longer to dry? Clean the dryer screen in HOT water if using fabric softener sheets. They leave a residue that impedes air-flow, costing you money. Clean the ducting in the last six months? 17,000 dryer fires annually!

11-04-2012, 08:10 PM	#3
Windows on Wash Exterior Construction Join Date: Aug 2011 Location: VA, MD, DC Posts: 3,861	batt insulation and blown in You will get some compression but you gotta cover those rafters and the cellulose is better are resisting convection. Make sure the cans are sealed up tight and not just IC rated. __________________ To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

11-04-2012, 08:56 PM	#4
langless28 Member Join Date: Nov 2011 Location: MA Posts: 154	batt insulation and blown in Thanks for the responses. I actually read some older posts stating the weight differences. Do they make r30 faced rolls of insulation? I was looking at the two big box stores and it seems that faced r30 is only sold in the precut (more expensive) variety.

11-04-2012, 09:24 PM	#5
Fix'n it Member Join Date: Mar 2012 Location: far sw sub chicago Posts: 1,956	batt insulation and blown in why are you using batts ? and not just blowing more cellulose ? __________________ DIY'er, out of necessity. if i did this for a living, i would make about $3.50 an hour To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. i didn't make this world. i just live in it. be careful of whom you make fun of. one day, that could be you...

batt insulation and blown in