When it comes to building a shower, one crucial decision lies beneath the surface: choosing the right material for the shower backing. This backing provides the structural support for your waterproofing layer and tile, ensuring a long-lasting and damage-free shower.
Two common contenders for this role are plywood and oriented strand board (OSB). Both are engineered wood products, but they have distinct properties that make them suitable for different applications.
Understanding the Options
Plywood: Made from thin layers of wood veneer glued together with alternating grain directions, plywood is known for its strength, stability, and resistance to warping.
OSB: Manufactured from wood strands bonded with adhesives and compressed into panels, OSB is generally less expensive than plywood and offers good shear strength.
Why Choose Plywood for Shower Backing?
Moisture Resistance: While neither construction standare plywood nor OSB is inherently waterproof, plywood, especially when treated for exterior use or marine applications, tends to hold up better against moisture. This is crucial in a shower environment where water exposure is inevitable.
Strength and Stability: Plywood's cross-grained construction provides superior strength and stiffness, making it less prone to sagging or flexing under the weight of tile and water.
Smooth Surface: Plywood generally offers a smoother surface for attaching waterproofing membranes and tile, ensuring a more even and aesthetically pleasing finish.
Why Choose OSB for Shower Backing?
Cost-Effectiveness: OSB is typically more affordable than plywood, making it an attractive option for budget-conscious projects.
Availability: OSB is often more readily available than plywood, especially in certain regions.
Uniformity: OSB has a consistent density and thickness throughout the panel, which can be advantageous for some applications.
When is Solid Blocking a Better Choice?
While plywood and OSB are common choices for shower backing, there are situations where solid blocking, such as 2x12 lumber, might be preferable:
Increased Support: For heavy fixtures like showerheads or grab bars, solid blocking provides a more secure anchoring point.
Specific Design Needs: In custom showers with unique shapes or features, solid blocking offers greater flexibility for creating curves and angles.
Enhanced Durability: In areas prone to high moisture or potential leaks, solid blocking provides an extra layer of protection against water damage.
Expert Opinions
Home Builders: Many builders prefer plywood for its overall performance and longevity, especially in high-end homes where quality is paramount.
Carpenters: Carpenters often appreciate plywood's ease of handling and the smooth surface it provides for tile installation.
Plumbers: Plumbers may prefer solid blocking for securing shower valves and ensuring a stable base for plumbing fixtures.
Left Over: Most of the time, carpenters use scraps of left over materials and if they have plywood, OSB or blocking, then that is what will be used.
