How to insulate an inaccessible area of 2 story home

[DocJatTTU]

Greetings all. New to the board here and have a question about attic insulation. I bought a home in July and the electric bills this summer were staggering. $500 plus a month is ridiculous for a 2500 sq foot home. Its 2 levels but only over half of the house. the rest just has high ceilings. The insulation is meager at best. The attic access only allows access to half the attic and the rest is blocked by extensive duct work and the pitch of the roof. I can just barely see past the duct work out into the expanse of open dead space that is over the high ceiling in the living room and kitchen. I really want to spray in attic batting but dont want to take down the duct work and remove the air handlers. I am wondering if it would be advisable or feasible to cut an opening into the ceiling of the kitchen and formal dining area to spray in insulation? Or would it be better to call in an HVAC co to remove the ducting for me so I can access the space? any help is greatly appreciated!
Thanks in advance.
Jon

 

[dovetail]

I'm a bit confused as to what you are trying to accomplish. Batts are not blown in they are placed. The problem with cathedral ceilings is when insulation is installed it generally does not allow air flow (venting) which can result in damage from ice dams, moisture being trapped, and mold growth. The most economical approach would probably be to remove the drywall and install rigid foam insulation boards making sure to allow space for airflow above them (use baffles to accomplish this). You get an R value of 6.5 per inch (thickness) of board. Then install new drywall. Removing and reinstalling the drywall will be much more economical then bringing in an HVAC company to remove the air handler and duct work. If air tight and un-vented is your goal I would use closed cell foam insulation (this is not diy and will require a contractor to perform). You should be able to use cellulose blown in insulation in the open attic without any issues. If you have blown in already, install fiberglass batts perpendicular to the framing over the blown in for additional R value.

 

[DocJatTTU]

Dovetail thanks for the reply. I mispoke when I said blow in batting. What I meant was blow in insulation such as Atticat from home depot. I don't really want to take down a lot of the drywall on the ceiling but I was thinking I could cut a man sized hole to allow me to get up inside that area. Then I'd like to blow insulation in.

 

[GrandpaDan]

How about the roof? What kind of roofing do you have? I've done insulation in such a space by cutting a hole between trusses at the peak, and doing it all from the outside.

 

[DocJatTTU]

It actually has a new shingle roof that was installed right before I purchased the home. Unfortunately they opted for the cheap route and put it on top of the old roof. Opening that up seems to me like it'd be a nightmare

 

[GrandpaDan]

I guess it's all what you are more comfortable with. I'd find it easier and cleaner to take off enough shingles to get to the roof deck, cut an access hole between trusses, blow it in from there, sister some nailers on the sides of the trusses, nail the decking back in, replace the shingles. If you are careful, you won't need extra shingles, but if the roof was just done, you should have a few extra shingles somewhere. Cutting a hole in the drywall is easy enough, it's patching back, matching texture and paint that I'd rather not do. Plus cleanup of insulation in the house from the blowing. Name your poison?

 

[dovetail]

Be careful what you cut through to gain access. If you're not sure what as to the nature of what you are going to cut it would be worth your while to get a professional opinion as to whether or not it is safe to cut it. You could have a contractor or structural engineer look at it for a nominal fee in most cases. Better safe than sorry if you get my drift. If your going to use blown in I would just use a 5-6" hole saw to open up a spot in each bay to blow in the insulation. I definitely would not go through the roof as no matter how careful you are removing shingles they will get damaged to some degree when removing them. If you bring one of the cut outs to a Sherwin Williams they can usually match the paint with no problems. Save all the cut outs, stick a 1 x 4 across the hole on the inside and use drywall screws through both the ceiling and the "patch". Then tape, mud, and sand. Or you could install can lights for extra lighting in the cut outs. If you do install cans you will have to plan the locations carefully and make sure you use IC rated cans.

 

[DocJatTTU]

GrandpaDan and dovetail thanks for the advice. I think I have just about made up my mind to cut access into the drywall ceiling. Matching texture is something I've never had the touch for. I have a contractor that I've used to patch and texture for me in the past and he does great work for a fair price. One last question. I have recessed lighting in the ceiling in a couple spots. If I change those out to LED would I still need to make boxes around them before I blow insulation in?

 

[GrandpaDan]

Speak for yourself, I guess. I've done it both ways. I'm guessing you have sissor trusses? What is the roof pitch? How much space do you have between the top and bottom chords of the trusses at the peak? Is it enough to crawl through at the ridge?
I wouldn't try to cut holes in the drywall and blow it in...how do you know you have coverage.

 

[GrandpaDan]

GrandpaDan and dovetail thanks for the advice. I think I have just about made up my mind to cut access into the drywall ceiling. Matching texture is something I've never had the touch for. I have a contractor that I've used to patch and texture for me in the past and he does great work for a fair price. One last question. I have recessed lighting in the ceiling in a couple spots. If I change those out to LED would I still need to make boxes around them before I blow insulation in?

It depends on what is already there...a lot of can lighting is already enclosed, and LED's run a lot cooler than other lights. What kind of insulation are you blowing in?

 

[dovetail]

Check the boxes, should be a sticker inside the accessible part that indicates its rating. We typically remove them and install IC rated if we can't confirm the rating. You just use remodel cans for the additional lights. Regardless of the intent to use LEDs you still need to install the proper type of fixture for the application. If someone down the road installs a typical bulb you will then have a fire hazard. By the way IC stands for insulation contact. They are required by IRC and NEC code when the lights will be in contact with insulation.

Grandpadan, blown in cellulose is commonly installed using this method. My biggest concern is actually overfilling the area and cutting off airflow. The insulation will pack quite nicely in tight quarters.

Are the ceilings textured? If so popcorn, stippled, or plastered? Smooth ceilings are easily patched. Popcorn and stippling are more difficult to match and generally more expensive.

 

[GrandpaDan]

All depends, Dovetail...How is the space above the ceiling vented now? Are there soffit vents? What kind of venting is installed now? Ridge vent?
Back to the ductwork...what does that ductwork serve, and with what? Is it insulated? Is there an air handler or something up there?

Sorry if I didn't see where you are located...the procedures change depending on where you live. Where do you live?