2nd layer sheetrock for ceiling?

We're planning on doing some remodeling soon and have a question about whether or not we can install a 2nd layer of sheetrock on the ceiling?

The current ceiling (in this 1950's built home) was installed poorly (with sheetrock running parallel with joists instead of perpendicular) thus causing many sags. It is also a covered with what appears to be a sprayed on texture.

Can we just install a 2nd layer of sheetrock over this? Really don't want to have to take it down if possible (thus avoiding having to remove the insulation from the attic and creating a big mess).

This remodeled room will eventually become a bathroom. Do we need to use the greenboard type of sheetrock on the ceiling (& eventually walls?) What thickness sheetrock should/could we use if we can install a 2nd layer?

Appreciate any insight given!

 

It should be ok providing you use screws long enough to secure the drywall to the ceiling joists. 1/2" drywall is fine if the joists are on 16" centers. No need for greenboard - primer and latex enamel will provide all the protection the drywall needs.

 

Thank you very much for your reply marksr! I was soooo hoping this was doable! The ceiling joists are 16" oc, so will be sure to use long enough screws for attaching.

But I still have a few more questions, if you wouldn't mind to answer.

You stated that with proper primering and latex enamel paint, all should be good. Can we still texture the ceiling? Is the primering/painting done prior to that or after?

Thanks again for your help!

 

Some say to prime prior to texture and that does allow the texture to dry at an even rate BUT I have never seen a need to prime the wall prior to texture since the texture also needs priming. I'd finish the drywall work, texture the ceiling, then prime and paint.

 

I think the roughness of the texture is an important factor. If it is rough, I would define that as 1/4" difference between high and low points, then I would recommend knocking down the texture or installing a sleeper system. If you simply try to laminate gyp board over existing you are going to have a bunch of blown out screws and a wavey surface plus I can't think that 1/2" gyp board is stiff enough to eliminate the belly in an already sagging ceiling.
I would recommend installing a sleeper system using a laser level and shims. The substructure wouldn't have to be heavier than 2x3's at 16" o.c. running perpendicular to the rafters. You could then add some insulation and install your gyp board. You will end up with a perfectly true and level ceiling. Of course this only works if you don't have any conflict with the window & door heads/ trim