Bonus Room Insulation Woes

Hi. I've been lurking around a bit waiting for time to assess my attic before I posted for advice. There are a lot of words here but I'm trying to be detailed.

I bought this house 3 years ago and the bonus room, attic converted space, has always been hot during summer and cold during winter. I always thought it was due to lack of HVAC vents. After reading around and my 'inspection' this weekend I know the temperature extremes are due to poor insulation. There are many air gaps on both the knee walls (img 4) and the ceiling (img 3) insulation, which I was hoping to fill with blown in cellulose insulation.

I need guidance on how to best fix the air gaps in insulation letting hot air touch the drywall. I've read that insulation needs to be attached to the face of the studs on the knee wells; I don't understand this. All insulation is stapled to the side of the studs near the drywall.

Numbered according to the pictures below.

1. The attic itself is fairly well insulated.
2. There was significant air gap in both HVAC vents. I stuffed the insulation around it as a temporary fix.
3. There builder installed foam spacers to allow air flow to the ridge vents.
4. Notice the air gap between the insulation and the drywall. The big issue is the air gaps in the insulation and the dry wall.

Extra notes:

• There is insulation between the floor and ceiling of downstairs; I need to ensure there are no air gaps between the floor joists. They are pretty well closed off with insulation.
• There are 2 doors separating the attic and the bonus room. Both doors are cheap inside doors with no insulation. I need to insulate these by attaching foam board to the attic side.

Attic - ridge vents
Room - 338 sq ft

HVAC (frame measurements)
2 vents - 16x8
1 return - 17x22

Note: during summer the HVAC unit runs for <8 minutes, so adding another vent in the bonus room is on my list after I finish the insulation.

All Images: http://imgur.com/a/RfRTa

(1)


(2)


(3)


(4)

Face stapling or side stapling is a "method" and, faced, loose blanket insulations will by expansion fill any voids, except irregular stud spacing.

It's important to install with the facing toward the conditioned side.

If your insulation does not approach these standards; https://www.energystar.gov/index.cfm?c=home_sealing.hm_improvement_insulation_table, you have some improvements to ponder. Consider the knee walls as ceiling, and not walls.

As for the doors a threshold, door bottom and jamb weather strip will improve the condition substantially.

If the room is to be consider as habitable space, consider fire rated weather strip for the door, and a smoke detector.

Your AC unit may never be up to the task of cooling the extra floor. The insulation doesn't look bad in the pictures, you can certainly work go improve any gaps in that, but I doubt you'll see a significant improvement. The benefit of doing one of these is the noisy part is located away from the living space and it allows you to zone the heat/AC to just where it is needed. Trying to make your existing unit take on the extra space may mean cooling the rest of the house cooler than you want/need to get the attic to the temperature you want. Retro-fitting zone controls is difficult.

Around here when people finish their attics they typically add a new unit for the attic. A ductless mini-split system is ideal for this type of application. http://energy.gov/energysaver/ductless-mini-split-heat-pumps

One brand, there are many manufacturers of these systems.
http://www.lennox.com/products/heating-cooling/mini-split-systems

Snoonyb said:

Face stapling or side stapling is a "method" and, faced, loose blanket insulations will by expansion fill any voids, except irregular stud spacing.

It's important to install with the facing toward the conditioned side.

If the room is to be consider as habitable space, consider fire rated weather strip for the door, and a smoke detector.

Click to expand...

Everything you said makes sense, except I'm really having trouble envisioning this. The face is the paper side. If I face staple the insulation do I staple to the dry wall straight through the insulation?

Sparky617 said:

Your AC unit may never be up to the task of cooling the extra floor. The insulation doesn't look bad in the pictures, you can certainly work go improve any gaps in that, but I doubt you'll see a significant improvement. The benefit of doing one of these is the noisy part is located away from the living space and it allows you to zone the heat/AC to just where it is needed. Trying to make your existing unit take on the extra space may mean cooling the rest of the house cooler than you want/need to get the attic to the temperature you want.

Click to expand...

This house was built in 2007 and as far as I can tell they designed the HVAC with the bonus room in mind. Also, the only stairs in my home lead to this room, it would be odd to have stairs just to go to a hot attic. After only 8 years the insulation is degrading and the vent was separating from the wall.

My original through was a mini split system. If it comes to this I'll go through with it. I've always wanted a home theater so I'm working towards that.

My apologies, I had assumed that you were asking for a future installation and that the framing was open and uncovered.

There are two methods for this type of installation, "gently" drive several 2" coarse thread drywall screws through the fiber into the drywall, without penetrating the drywall,
or, spray some SCOTCH 777 adhesive, or another thick bodied spray adhesive and insert the insulation.

The adhesive has a short set time, so it pays to have the insulation precut.

OK, that sounds easy. My next major problem is the ceiling. For filling the air gap at the bottom (pic in 1st post); is it best to use spray foam or stuff blow in insulation?

The question above applies to filling the gap between the floor and the ceiling. There is insulation but is blown in insulation enough?

Also, I'm looking to invest in a File IR camera for Android, ($250), to better insulate my entire home.

biguglydofus said:

OK, that sounds easy.

Click to expand...

I'd like to step back. If you are just increasing the insulation to equal a recommended R value, you should use unfaced blankets and a web of tie wire secured to the studs and the width is not important.

biguglydofus said:

My next major problem is the ceiling. For filling the air gap at the bottom (pic in 1st post); is it best to use spray foam or stuff blow in insulation?
The question above applies to filling the gap between the floor and the ceiling. There is insulation but is blown in insulation enough?

Click to expand...

If you are referring to the photo with the open rafters and visible venting, please be aware that attic ventilation is 1:300, IE., 1sq.ft of vent for every 300 sq.ft. of attic area. So before adding insulation you need to install a baffle that prevents the insulation from obstructing these vents.

You can rent a blower for insulation, however, if with the employment of the IR camera you discover your walls also need an update, some planning my be in order.

Another method, 1 man, is to use unfaced batts.

biguglydofus said:

Also, I'm looking to invest in a File IR camera for Android, ($250), to better insulate my entire home.

Click to expand...

I'd consider that weighing alternatives may be a first investment.

Snoonyb said:

I'd like to step back. If you are just increasing the insulation to equal a recommended R value, you should use unfaced blankets and a web of tie wire secured to the studs and the width is not important.

Click to expand...

This will take care of the walls. Right now there is only R-13 on the walls.

This weekend I was able to spend time in this room when the temp was >90*F. I found problem areas that need addressing in the ceilings. There is ~8 areas that are warm to the touch between the ceiling joists where the slopped ceiling meets the flat ceiling; the red spots in the image below. The are was about 6" long and covered the entire joist. The rest of the ceiling below the red is cool to the touch.

There is no access in the ceiling to get to the red areas. Aside from tearing the ceiling out the best way to fix this is to cut out an access door and fill the problem areas with insulation.