In April I had an energy audit done to my new home. One of the big findings was my house did not have enough insulation in the attic. There is a lot of heat exchange from the 2nd floor into the attic through gaps in the walls, light and electrical sockets and other areas. The company who performed the audit suggested to add an additional 8 inches of blown cellulose insulation in to the attic on top of the existing pink insulation bats that lay in between the attic floor joists. The problem is I would no longer be able to use the attic for storage(xmas decorations, clothes, ect.). So I decided to find a solution. After extensive research online I found there was not much out there that had been done or documented.
Step 1: The Layout
In the picture it is clear there is a large space in the attic. In order for the cellulose insulation to work at its best it can not be compressed. So I decided to build a floating storage platform. I used a plum-bob from the center point in the roof and made a center line. Next I measured from that line just shy of 6 feet to both sides. I then cut 4ft lengths of 2 x 4 to create the studs.
Step 2: Studs
I then cut 4ft lengths of 2 x 4 to create the studs. I attached them to the attic floor and ceiling joists using 5/16 nuts and bolts with lock washers.
I then laid out all of the cross joists. I used 2 x 6 x 12 boards. I marked each stud so the bottom of the joist would be 10 inches above the floor joists to allow for the 8 inches of insulation.
Step 4: Platform
These pictures show the main platform. It is a little over 11 ft wide and 10 inches above the floor rafters. There will be 8 inches of blown cellulose insulation. The last picture shows the clearance between the pink bat insulation on the attic floor and the new platform.
Step 5: The Hatches
In addition to the storage platform I needed to create insulated hatches to cover a whole house fan that we use in the summer and a pull down attic ladder. I used ply wood to create the structure and then added thin house wrap insulation board that my parents had leftover, and some 1 inch green insulation board. The ply wood is sandwiched between the 2 types of insulation. I used sheet rock screws to attach the green board and staple to attach the house wrap insulation. I used metal insulation tape to cover all of the seams between the green insulation board and the screw holes(I did some of this process after taking the pictures). Once the walls were insulated I used spray foam insulation around the bottom and crevices on the inside and outside of the hatches.
I used the same process to create the lids. I needed to do some work to make inside covers fight tightly. I also added weather stripping material to the seam between the top of the hatches and the lids. I used some big strap hinges to hold the lids on. When open the lids rest against a support beam and on some rope attached to a roof joist. I also needed to make a wooden handle for the attic hatch to be able to close the lid from the stairs. In the last picture I decided I wanted the attic hatch to be more tightly closed. I used eye bolts and a bungee cord to secure the hatch down.
Step 6: Almost Done
When I decided to create the hatch on the whole house fan I realized I would need a way to access the hatch because I would not be able to walk on the floor rafters once the additional insulation was added. I decided to add a catwalk platform based on the idea of the other large platform. All I have left to do is to wait for the company to come to install the insulation. It was suggested to me to wait to put down plywood on the platform until after the insulation was added as it would make the job more difficult. once the insulation is add I will add the plywood and screw it all down which will add more lateral strength to the platform joists. Once I have all of the insulation added I will include a new picture.
Disclaimer: Everyone else seems to have one on this site so here is mine. This was a solution for my house. This may not work for yours and I am not responsible for any damage to you or your house.