Choosing the right panel thickness is one of the most common sources of error in drywall design. The decision depends on two clear variables: the distance between studs and the load applied to the surface.
Why stud spacing matters
Between two adjacent studs a gypsum board behaves like a simple beam. As spacing grows, the bending moment increases non-linearly, so doubling the distance multiplies deflection several times over.
Quick selection table
- Up to 40 cm — 9.5 mm, single layer
- Up to 50 cm — 12.5 mm, single layer
- Up to 60 cm — 12.5 mm, single layer (maximum)
- Above 60 cm — 15 mm or double layer
For ceilings and horizontal surfaces, reduce the allowable spacing by about 20–25%.