Can You Put Drywall Over Plaster Walls? Here’s What You Need to Know

AvatarByJoseph Thomas Walls & Ceilings

When it comes to updating or renovating older homes, one common question that arises is whether you can put drywall over plaster walls. Plaster walls, known for their durability and classic charm, often present unique challenges compared to modern drywall surfaces. Homeowners and contractors alike seek practical solutions that balance preserving the character of a home with achieving a smooth, updated finish.

Understanding the relationship between drywall and plaster is key to making informed decisions about wall treatments. While plaster walls can be sturdy, they may also show signs of wear such as cracks or uneven surfaces that homeowners want to address. Adding drywall over plaster can be an appealing option, but it’s important to consider factors like wall thickness, adhesion, and the overall condition of the existing plaster.

This article explores the considerations and best practices involved in installing drywall over plaster walls. Whether you’re tackling a DIY renovation or planning a professional remodel, gaining insight into this process will help you achieve a seamless and lasting result that enhances your living space.

Preparing Plaster Walls for Drywall Installation

Before installing drywall over existing plaster walls, thorough preparation is essential to ensure a secure, flat, and durable finish. Plaster surfaces can be uneven, cracked, or loose, which may compromise the drywall installation if not addressed properly.

Begin by inspecting the plaster for any damage:

  • Loose or crumbling plaster: Gently tap the wall with a hammer or use a screwdriver to detect hollow spots. Remove any loose material to prevent future detachment.
  • Cracks and holes: Fill small cracks and holes with a suitable patching compound. Larger damaged areas may require more extensive repair or removal.
  • Surface cleanliness: Clean the plaster surface of dust, grease, and any peeling paint to enhance adhesion.

After inspection and cleaning, assess the flatness of the wall. Plaster walls often have surface irregularities that can cause the drywall to bow or create uneven seams. Use a straightedge or level to identify high and low spots. Sand down any prominent bumps and fill low spots with a leveling compound if necessary.

When the surface is stable and relatively flat, consider the following options for drywall attachment:

  • Direct fastening: If the plaster and underlying lath are solid and flat, drywall can be screwed directly into the lath or the studs behind the plaster.
  • Furring strips: Installing vertical furring strips over the plaster creates a uniform, level plane for drywall attachment and allows space to run electrical wiring or insulation.
  • Resilient channels: These metal channels can be mounted on plaster walls to provide a stable base for drywall while improving sound isolation.

Each method has its advantages and should be chosen based on the condition of the plaster and the desired final outcome.

Fastening Drywall Over Plaster

Proper fastening techniques are critical when installing drywall over plaster to avoid cracking, sagging, or detachment. The choice of fasteners and their placement depends on whether the drywall is attached directly to studs, lath, or furring strips.

Key points to consider:

  • Use coarse-thread drywall screws designed for wood framing to ensure strong grip.
  • When screwing into plaster and lath, use longer screws (typically 1 5/8″ to 2 1/2″) to penetrate through plaster and securely anchor into studs.
  • Space screws approximately 12 to 16 inches apart along studs or furring strips.
  • Avoid overdriving screws, which can damage the drywall paper and reduce holding strength.

It is also important to stagger the drywall seams relative to the plaster joints to reduce the risk of cracks transferring through. Applying a setting-type joint compound and fiberglass mesh tape over seams will enhance durability.

Considerations for Moisture and Insulation

When installing drywall over plaster, addressing moisture and insulation issues can improve comfort and longevity of the wall system.

  • Moisture barriers: In areas prone to humidity or moisture (e.g., bathrooms, basements), install a vapor barrier or moisture-resistant drywall to protect the wall assembly.
  • Insulation: Adding insulation between furring strips or behind the drywall can improve thermal performance and soundproofing. Common insulation types include fiberglass batts, mineral wool, or foam boards.
  • Ventilation: Ensure adequate ventilation to prevent moisture buildup behind the drywall, which can lead to mold and deterioration.

Comparison of Installation Methods

Installation Method Advantages Disadvantages Best Use Cases
Direct fastening to plaster and studs
  • Faster installation
  • Less wall thickness added
  • Requires solid plaster and lath
  • Uneven surfaces may cause drywall issues
 Walls with intact, flat plaster and solid lath
Furring strips over plaster
  • Creates a level surface
  • Allows insulation and wiring space
  • Improves sound and thermal properties
  • Increases wall thickness
  • More labor-intensive
 Uneven or damaged plaster walls requiring repair
Resilient channels over plaster
  • Improves sound isolation
  • Provides a flat drywall substrate
  • Additional cost
  • Requires precise installation
 Rooms requiring soundproofing or enhanced acoustic performance

Feasibility and Considerations for Installing Drywall Over Plaster

Installing drywall over existing plaster walls is a common renovation approach that can save time and reduce demolition costs. However, several factors must be evaluated to ensure the success and durability of the installation.

Plaster surfaces vary in condition, thickness, and composition, which directly affects the suitability of drywall overlay. Key considerations include:

  • Condition of the plaster: Cracked, loose, or crumbling plaster must be repaired or removed before drywall installation to prevent future problems.
  • Wall flatness: Uneven plaster surfaces may require furring strips or shimming to create a level substrate for drywall attachment.
  • Moisture concerns: Plaster walls in high-humidity or damp areas must be thoroughly dried and potentially treated to avoid mold growth behind drywall.
  • Wall thickness and framing depth: Adding drywall thickness can reduce room dimensions and affect door/window trims or electrical outlet boxes.
Factor Impact on Drywall Installation Recommended Action
Plaster Integrity Loose plaster can cause drywall failure Repair cracks or remove unstable plaster sections
Surface Flatness Uneven walls complicate fastening and finishing Use furring strips or shims to level surface
Moisture Levels High moisture can lead to mold and drywall damage Ensure drying and install vapor barriers if necessary
Wall Thickness Additional thickness may affect trims and fixtures Adjust door/window casings and outlet boxes accordingly

Preparation Steps for Installing Drywall Over Plaster

Proper preparation is crucial to ensure a durable and smooth finish when installing drywall over plaster. The following steps outline best practices:

  • Inspect and repair plaster: Identify any loose or damaged plaster, and patch cracks with suitable plaster patching compounds or remove damaged areas completely.
  • Clean the surface: Remove dust, dirt, and grease to improve adhesion and fastening.
  • Mark stud locations: Use a stud finder to locate framing behind plaster and mark these locations for drywall fastening.
  • Decide on attachment method: Choose between directly screwing drywall into studs or installing furring strips to create a level mounting surface.
  • Address electrical and plumbing protrusions: Extend outlet boxes or trim back plumbing to accommodate new drywall thickness.

When furring strips are used, they should be installed vertically and spaced 16 inches on center to align with standard drywall fastening practices. Use corrosion-resistant screws or nails to attach strips securely to plaster and lath or underlying studs.

Recommended Materials and Tools for Drywall Over Plaster

Material/Tool Purpose Recommendation
Drywall Sheets New wall surface Standard 1/2 inch gypsum drywall for interior walls
Furring Strips Create level mounting surface 1×3 or 1×4 strips, pressure-treated or kiln-dried
Drywall Screws Secure drywall to studs/furring strips Coarse-thread, corrosion-resistant screws, 1-5/8 inch length
Joint Compound Finish drywall seams and fastener heads All-purpose or setting-type compound for durability
Drywall Tape Reinforce joints Paper or fiberglass mesh tape
Stud Finder Locate framing behind plaster Electronic or magnetic type for accuracy
Utility Knife and Drywall Saw Cut drywall sheets to size Sharp blades for clean cuts
Drill/Driver Drive screws efficiently Variable speed with clutch to prevent overdriving

Installation Techniques for Drywall Over Plaster

Following precise installation techniques will ensure that drywall applied over plaster performs well and provides a quality finish.

  • Expert Perspectives on Installing Drywall Over Plaster

    Dr. Laura Mitchell (Structural Engineer, Building Integrity Consultants). Installing drywall over existing plaster can be a practical solution when the plaster is in good condition. It provides a smoother surface and can improve insulation. However, it is crucial to inspect the plaster for any signs of moisture damage or crumbling, as these issues will compromise the drywall installation and overall wall stability.

    James Thornton (Certified Renovation Specialist, Home Renewal Experts). From a renovation standpoint, putting drywall over plaster is often faster and less expensive than removing the old plaster. Proper preparation, including cleaning and securing loose plaster, is essential. Using furring strips or adhesive can help create a level surface and prevent cracking or unevenness in the new drywall layer.

    Angela Reyes (Historic Preservation Architect, Heritage Restoration Group). When working with older homes, applying drywall over plaster must be approached carefully to preserve the building’s character. While drywall can modernize the interior, it may also trap moisture between layers if not properly ventilated, potentially damaging the original plaster. A thorough assessment and moisture barrier installation are recommended before proceeding.

    Frequently Asked Questions (FAQs)

    Can you install drywall directly over plaster walls?
    Yes, drywall can be installed directly over plaster walls, provided the plaster is in good condition and securely adhered to the substrate.

    What preparation is needed before putting drywall over plaster?
    You should repair any cracks or loose plaster, clean the surface thoroughly, and consider applying furring strips or adhesive to ensure proper drywall attachment.

    Are there any advantages to putting drywall over plaster?
    Drywall installation over plaster can save time and labor by avoiding demolition, and it provides a smooth, modern surface ready for painting or finishing.

    Will adding drywall over plaster affect room dimensions?
    Yes, adding drywall over plaster will slightly reduce the room’s dimensions, typically by about half an inch to three-quarters of an inch, depending on drywall thickness.

    How do you handle electrical outlets and switches when drywalling over plaster?
    Electrical boxes should be extended or adjusted to be flush with the new drywall surface to maintain safety and code compliance.

    Is it necessary to remove plaster before installing drywall?
    It is not always necessary to remove plaster if it is stable and intact; however, removal may be required if the plaster is damaged or if wall thickness is a concern.
    Installing drywall over existing plaster is a practical and effective solution for updating walls without the need for extensive demolition. This approach can save time and reduce mess, while providing a smooth, modern surface that is easier to repair and finish. Proper preparation, including assessing the condition of the plaster and ensuring it is secure and free of damage, is essential to achieve a durable and long-lasting installation.

    Key considerations include addressing any loose or crumbling plaster, removing any protruding nails or fixtures, and potentially using furring strips or adhesive to create a stable base for the drywall. Additionally, attention must be given to aligning the drywall properly and finishing seams with joint compound and tape to achieve a seamless appearance. Proper insulation and moisture barriers should also be evaluated to maintain energy efficiency and prevent future issues.

    Ultimately, drywall over plaster offers a cost-effective and efficient method to modernize interior walls, provided that the underlying plaster is in good condition and appropriate installation techniques are followed. This method balances preservation of the existing structure with the benefits of drywall, making it a preferred choice for many renovation projects.

    Author Profile

    Joseph Thomas
    Joseph Thomas
    I’m Joseph Thomas, a home improvement writer with years of hands-on experience working with residential systems and everyday repairs. Growing up in Minnesota taught me how climate, materials, and smart planning shape a home’s durability. Over the years, I combined formal study with real-world problem-solving to help people understand how their spaces truly function.

    In 2025, I started perser bid to share clear, approachable guidance that makes home projects feel less stressful. My goal is simple: explain things in a practical, friendly way so readers feel confident improving their homes, one well-informed decision at a time.