[Dr K]

I did a search and read the prior insulation threads, and the insulation part of Pookie's attic fan thread.

We had a home energy audit because our electric bills are both high and the same throughout the year (we have gas heat, so the bills should be higher in the summer).

The largest item on the audit, likely the most helpful, but the most expensive estimate-wise is to improve the insulation in our attic.

I'll go into the specifics first, and then post my questions:

Currently, we have 4-6" of cellulose insulation, going to the eves (no baffles), not sealed on the tops of the walls (suggestion to do that in the report with baffles) and without covers on the recessed lighting allowing significant airflow through the light fixtures.
There is also installed 3/4" plywood "flooring" (4x8 sheets) through about 1/3 of the attic, going end-to-end (approx. 70 feet) and the width of the bottom of the W-shaped rafters (8 feet).
There was also significant leakage around the drop-down door.
There are 2 sky tubes which are neither sealed nor insulated, and 2 bathroom vents which are also not insulated (one is a single fan remote fan drawing two low-noise vents and would be very difficult to insulate other than insulated flex tube, and I don't want to make Jesus cry).
There are vents (about 2 x 2.5") at either end of the attic, plus when we recently replaced our roof, we installed a ridge vent running the length of the attic

The recommendations are;

• Seal accessible top plates and end walls with foam
• Seal and insulate sky tubes
• Seal all penetrations through attic floor (plumbing, etc.) with foam
• Install covers on recessed lights so the are insulation compatible and airtight
• Insulate to R49 (16" of insulation) with fiberglass or cellulose
• Install baffles so the eave vent air goes over the insulation
• Install an attic tent over the door
• This would involve installing 2x6's and raising the flooring to accomodate the added insulation

Questions:

1. Is there denser insulation available to install beneath the flooring as I'd hate to lose 5" of height (I'm pretty tall...)?
2. How much insulating value is the 3/4" plywood itself?
3. Is the attic tent a good solution, or would the experts here weatherstrip the door?
4. How much of the above can I do myself relatively easily? The estimate is quite a few sets of Hoosiers worth!
5. Is this a job I should just plunk down the money because it's hot as blazes up there and much of it is a crappy job, or is it one of those things like changing brake pads -- "I can't believe I paid somebody that much to do this job?"