Two layers of drywall or OSB + drywall

Hi everyone,

I had a drywall contractor at the house yesterday for a quote. He said he would install one layer of OSB boards under the insulation in the attic and then one layer of drywall on top. It's cheaper that way than two layers of drywall (obviously).

Is that okay to do? Any disadvantages? That would also be the case in the bathroom (of course with green drywall).

Cheers!

We also have OSB+Rigips. The advantage for us is that we can easily attach something with Spax screws. With only Rigips, you would need those Rigips anchors.

Do you have that in the bathroom too?

Yes, and cabinets have held up without problems for four years. Then there are the green moisture-resistant boards.

Exactly, I was just afraid/concerned that moisture might seep in and the OSB might swell somehow. Thanks for the info!

Take Fermacell. They are thinner, significantly more stable, and suitable for damp rooms. Cost a bit more, but you need slightly less substructure.