attic insulation

That will definitely allow you to get more insulation in. How important that is, and how much it will help, depends on what's there now and what climate you are located in.

Alot of trouble for access, insulation would be my first concern, storage or access the least of my worries. It is unheated, right. To get access you would have to raise the floor up very high. Im my case 18". Insulation codes are only minimums, optimal amounts would be found at Energy Star, even manufacturers recomendations I would follow with ever increasing utilities. The attic is the cheapest and easiest place to make the greatest difference in utility reduction since heat rises and it is cheap to do. Optimal ratings are often double of code.

that is exactly what i did

I used 2x10's and 1/2" plywood as cleats from the new lumber to the old. then screwed it all together. When the insulator came by all he had to do was shoot under the plywood flooring. I stuck with 4 foot wide. All I kept up there were card board boxes, flattened. Be careful that you do not put to much weight up there, ceilings are seldom designed for much extra weight on top of the structure.

Thanks, I like that idea. I do have a couple of smaller a/c units there, but they are coming down, since I'm having central a/c put in. No other heavy things up there. Chas

I woudn't install the floor over it without leaving gaps for ventilation. You don't want to trap any moisture in your insulation.

You are right. However, it is not a full floor, just planks going in strategic directions. Chas