Designing Kitchens and Bathrooms - double layer of drywall

I am remodeling a bathroom and about to redo the drywall on the ceiling. I am wondering if there is any problem with simply putting another layer of drywall up. The reason I would prefer to do this is because the attic above has blown in insulation, and taking the old drywall down would certainly create quite a mess.

The current drywall is really in bad shape, so it would be difficult to repair. I am somewhat concerned about getting the new layer of drywall nice and level, but I think this can be done... May have to shim it in places.

Dave

You can do this, just remember you're going to need longer screws than when installing a single layer.

I've used 3/8" drywall to cover a damaged wall that I didn't want to demo. It was quicker, cheaper and a lot cleaner than ripping out the old wall. The only thing different was that I used construction adhesive between the two surfaces. I wasn't sure if the 3/8" stuff would bow between studs so I wanted to make sure it stayed flat.

I'd only be worried about bowing if you used something thinner than 5/8. The reason for 5/8 on cielings is because of the tendency to bow. If your joists are 16" OC or less (rather than the 24" OC that roof trusses are) you can get by with 1/2.

Adhesive might work to stop that, but I'd rather be safe and use 1/2 " or 5/8" as the situation dictates. That's probably cheaper than adhesive anyway. Heavier though.