Insulation, Radiant and Vapor Barriers - Loose fill over batts

Would like to fill in the small gaps between the batt insulation in my attic floor and was thinking of loose fill. I have lots of duct work that rests on the attic floor joists that would make an additional layer of batt insulation difficult. I was thinking of fiberglass fill because of weight issues. I plan to add about an inch or two of loose fill over the entire 10 inch batt installation. Will the loose fill squish my batts? Anyone other considerations or pitfalls I need to be aware of.
Thanks,
John

Adding loosefill by hand is fine, though you'll likely go through more than if you used a machine. It tends to not spread/fluff as well by hand.

No pitfalls other than the standard keep it away from hot things (can lights, chimney stacks, etc).

Only thing I can say is that if you're going to be crawling around up there anyway, why not put more than an inch? Adding an inch will give you what, ~R3? Seems like a lot of effort for a little change when only a bit more effort will give you +R10-30 or depending on how much you put up there.

Go to http://www.owenscorning.com/worldwide/canada/HowTo.asp?HowToID=1&Language=1 to learn about insulation. Click the Insulation Calculator and type in your ZIP for recommended amount of insulation in your area.