Drywall Vs Plywood: Which Is Better for Soundproofing?
Soundproofing a room, office, or other living space is an important consideration for many homeowners and tenants. Choosing the right materials to reduce noise transmission through walls, ceilings and floors is key to creating a quiet environment. Two of the most common options for soundproofing projects are drywall and plywood. But which material works better?
Drywall and plywood both have advantages and disadvantages when used for soundproofing. There is no definitive “better” option, as the optimal material depends on factors like budget, existing construction, and performance goals. However, drywall generally provides higher noise reduction for most applications.
Here is an in-depth look at using drywall vs plywood for soundproofing, including key differences, installation tips, and recommendations for optimal noise blocking.
Drywall Offers Better Noise Reduction
For soundproofing projects, drywall is superior to plywood in most cases. Drywall has higher density and mass than plywood, which enables it to block more sound transmission.
Here are the key reasons drywall is better than plywood for soundproofing:
- Drywall has a density of 800-900 kg/m3, while plywood density ranges 460-680 kg/m3. The higher density of drywall helps block more sound waves.
- Drywall can be installed with multiple layers more easily and cost-effectively than plywood. Double or triple drywall layers increase mass and improve noise reduction significantly.
- Drywall’s smooth surface, compared to plywood’s uneven plies, reflects rather than absorbs sound. This reflective surface causes sound waves to bounce off instead of passing through.
- Drywall is non-structural, so it can be installed on resilient channels or double stud walls, which allow the drywall to vibrate independently from walls and floors for better decoupling.
- Specialized acoustic drywall like QuietRock has viscoelastic polymers that dampen vibrations and sound transmission. Plywood has no corresponding acoustic options.
- In real-world testing, double drywall assemblies achieve Sound Transmission Class (STC) ratings over 50, while double plywood walls struggle to reach 40 STC. The higher the STC rating, the more noise is blocked.
Research shows that thicker drywall improves sound isolation. Learn more about is thicker drywall better for soundproofing? in this helpful article.
To learn more about what is soundproof drywall and how it works, you can read this informative article. It provides an excellent overview of drywall’s sound blocking properties.
Plywood Has Limitations for Soundproofing
Although plywood has useful properties like strength and moisture-resistance, it is less optimal for soundproofing for these reasons:
- Plywood’s porous wood structure allows more sound to pass through, especially lower frequencies. Air gaps between wood layers transmit noise easily.
- Plywood is far more rigid than drywall. This allows sound vibrations to transfer through plywood walls and ceilings to the other side.
- Plywood cannot be staggered off studs or installed with special acoustic mounts. Its rigid connection to structural framing bridges sound flanking paths.
- Plywood is heavier and more difficult to install multiples layers. Doubling up 1/2″ plywood weighs over 4 pounds per square foot.
- No special acoustical plywood products exist that dampen noise like QuietRock drywall. Regular plywood offers minimal decoupling or damping.
For these reasons, plywood is not commonly used in wall assemblies for dedicated sound studios or home theaters. Drywall and acoustical sealants provide much higher noise blockage.
However, plywood still has useful sound blocking abilities if installed properly. Under certain circumstances, plywood can supplement a drywall soundproofing assembly.
Key Differences Between Drywall and Plywood
| Factor | Drywall | Plywood |
|---|---|---|
| Cost | $10-20 per 4×8 sheet | $30-60 per 4×8 sheet |
| Density | 800-900 kg/m3 | 460-680 kg/m3 |
| Strength | Low-Medium | High |
| Moisture resistance | High | Medium |
| Sound blocking | Excellent | Moderate |
| Decoupling ability | High | Low |
| Ease of installation | Easy | Moderate |
| Fire resistance | High | Low-Medium |
Table 1. Key Differences Between Drywall and Plywood
As seen in the table, drywall consistently outperforms plywood in metrics related to soundproofing. The only advantages of plywood are cost in some cases, strength, and moisture resistance.
How to Install Drywall for Soundproofing
To utilize drywall’s noise blocking abilities, proper installation is key. Here are best practices for installing drywall for soundproofing:
- Use 5/8″ Type X drywall instead of 1/2″ for more mass. Type X has fire-resistant additives that also dampen sound better.
- Install drywall on resilient channel furring strips instead of directly on studs. This decouples the drywall from the wall framing.
- Consider staggered-stud walls with two separate drywall layers on each side of staggered 2×4 studs. This prevents noise flanking and couples each drywall layer.
- Use acoustic sealant between drywall seams and screws. Sealants like Green Glue fill gaps that allow sound leaks.
- Apply damping compounds like Green Glue between drywall layers. Constraining damping material increases transmission loss through the assembly.
- Hang one layer of drywall horizontally, and the other layer vertically. This prevents seams from aligning and creates more mass.
- For new construction, consider double-stud walls with an inch gap between. This allows each drywall layer to be mounted on its own independent stud wall.
For ceilings, double drywall layered with Green Glue provides excellent overhead sound blocking. Read this guide on how to soundproof a drywall ceiling for tips.
With attention to installation details like these, drywall can achieve outstanding noise reduction between rooms. Work carefully to seal borders and openings.
To learn how to properly use soundproof drywall for your project, read this helpful guide on installation best practices.
How to Get the Most from Plywood
Although plywood is not ideal for primary soundproofing, it can still improve acoustic isolation if mounted properly. Follow these tips when using plywood:
- Choose thicker 3/4″ or 1″ plywood instead of 1/2″ for more mass. Thicker plywood has a bit higher STC rating.
- Install plywood using resilient isolation clips instead of screwing directly into studs or joists. This will decouple the plywood to prevent vibration transfer.
- Apply acoustic dampening caulk between plywood sheets and seal all edges thoroughly. This will help dampen and block sound leaks.
- Consider using plywood only on one face of a staggered stud wall, and drywall on the other face. The plywood adds mass while drywall provides damping.
- Look for special acoustical plywood options to provide more dampening and density. Products like Acousti-ply have enhanced soundproofing abilities.
- Combine plywood with materials like MLV (mass loaded vinyl) for added mass. MLV sheet installed behind plywood can raise STC ratings substantially.
With smart installation strategies and combining with other materials, plywood can supplement drywall to improve sound isolation in many structures.
Drywall vs Plywood Prices: Plywood is More Expensive
For soundproofing projects on a budget, drywall is the clear winner in terms of affordability. Let’s compare current prices:
| Material | Thickness | Price per 4×8 sheet |
|---|---|---|
| Drywall | 5/8″ | $12-14 |
| Plywood | 1/2″ | $30-50 |
| Plywood | 3/4″ | $50-80 |
Table 2. Price Comparison of Drywall vs Plywood
As you can see, a single 5/8″ sheet of drywall costs around $12-14. Meanwhile, basic 1/2″ plywood costs $30-50 per sheet – over twice as much! Prices for thicker, higher-grade plywood are even more expensive.
For large soundproofing projects covering hundreds of square feet, this price difference really adds up. Drywall provides outstanding “bang for the buck” with its affordability and noise blocking abilities.
While drywall and sheetrock function similarly for soundproofing, sheetrock is a brand name for drywall. Learn the key differences in this sheetrock vs drywall comparison.
Key Recommendations for the Best Soundproofing
Based on the research between drywall vs. plywood, here are my recommendations for achieving optimal soundproofing results:
- Use double or triple drywall layers wherever possible for maximum noise reduction. The more drywall, the higher the transmission loss.
- Look for specialized acoustical drywall like QuietRock for 20%+ better damping and decoupling abilities over regular drywall.
- Seal borders meticulously with acoustical caulk and calculate adequate drywall coverage for full wall/ceiling areas.
- Consider adding plywood only as a supplementary layer, not primary sound blocker, due to cost and weight concerns.
- Combine plywood with Green Glue, MLV, isolator clips or double-stud assemblies for increased performance.
- Work carefully around electrical, vents, recessed lights, and other openings to seal sound flanking paths.
Following these best practices using the most suitable materials will result in outstanding noise reduction and sound isolation between rooms or floors.
Conclusion
When choosing between drywall vs plywood for soundproofing projects, drywall is the clear winner in most situations. Drywall has higher density to block sound, costs less, installs easier in multiple layers, and achieves substantially higher noise reduction ratings in real-world testing.
Plywood still offers useful mass and strength properties. But for dedicated sound studios, home theaters, or music practice rooms, drywall is the surface material of choice. With careful installation sealing all gaps, drywall provides outstanding acoustic isolation between living spaces.
Key Takeaways
- Drywall blocks more noise than plywood due to higher density and mass. Drywall has an STC rating over 50, plywood under 40.
- Drywall can be double or triple layered more easily and cost-effectively than plywood.
- Specialized acoustic drywall like QuietRock dampens noise better than regular drywall or plywood.
- Plywood is more rigid so does not decouple or isolate noise vibrations as well as drywall.
- For primary soundproofing focus on drywall; use plywood only as a secondary layer with other products.
- Caulking, damping compounds and isolation mounting are key for drywall or plywood performance.
Frequently Asked Questions
Is drywall or plywood better for soundproofing walls?
Drywall is better than plywood for soundproofing in most cases. Drywall has higher density to block more noise, and allows easier installation of double or triple layers to increase sound transmission loss. Drywall also costs significantly less than plywood.
Can you use plywood for soundproofing?
Plywood can provide some level of soundproofing due to its mass, but it performs markedly worse than drywall. Plywood should only be used as a secondary sound blocking layer, not the primary barrier. The porous wood structure allows considerable noise passage.
Does plywood block sound better than drywall?
No, plywood does not block sound as effectively as drywall products. Plywood is more rigid so allows easier transfer of noise vibrations. Drywall is also easier to install with techniques like resilient channels that decouple it from the wall framing.
Is plywood a good soundproofing material?
Plywood has only moderate soundproofing abilities, with an STC rating around 30. It should only be used with other products like drywall or Green Glue for multi-layer assemblies. On its own, the porous wood structure allows significant noise to transmit through plywood panels.
Can you double up plywood for soundproofing?
You can install double layers of plywood for improved sound blocking, but this is heavy, expensive, and still much less effective than double drywall. Double plywood weighs over 4 pounds per square foot. If using plywood, it’s advised to combine it with drywall or damping products.
References
Wikipedia (https://en.wikipedia.org/wiki/Plywood)
Lowes (https://www.lowes.com/pl/Plywood-sheathing-Lumber-composites-Building-supplies/3221732066751)
This Old House (https://www.thisoldhouse.com/woodworking/21368970/types-of-plywood)
