Drywall Guide - Types, Installation, Repair & Tools

In this detailed, expert‑level guide to drywall (gypsum board), we focus strictly on structure, installation, repair, and technical specifications - not finishing materials, paints, or surface coatings.

Drywall is not a DIY material. Installation and repair require precision, experience, and an understanding of building codes. As professionals in the field, we provide this overview to highlight the complexity and importance of expert involvement.

What Is Drywall?

Drywall (gypsum board) is a panel made of gypsum plaster pressed between two thick sheets of paper. It forms the foundation of most modern interior walls and ceilings. Its popularity stems from its fire resistance, cost-efficiency, and ease of integration - but only when handled correctly by trained hands.

Types of Drywall

Using the wrong drywall can lead to structural issues or costly repairs. Professionals select the type based on the specific conditions of the space.

Standard Drywall (White Board / Regular Gypsum Board)

Standard drywall, also known as white board or regular gypsum board, is the most commonly used interior wall and ceiling panel. It’s designed for dry, climate-controlled spaces and does not offer enhanced protection against moisture, fire, or sound. Despite that, it remains the foundation material in both residential and commercial construction due to its cost-efficiency and versatility.

Composition & Construction:

Core: Non-combustible gypsum (calcium sulfate dihydrate)
Facers: Front and back covered in recycled paper
Surface: Paintable, texture-compatible, or finish-ready
Finish Types: Tapered-edge (for joint taping), square-edge (utility uses)
Compliance: Conforms to ASTM C1396 for standard gypsum panels

Sizes & Thickness Options:

Standard thickness:
- 1/2 inch - ideal for interior walls
- 5/8 inch - used on ceilings to reduce sag
- 1/4 inch - for curved applications or laminating existing walls
Panel sizes:
- 4′ x 8′ (standard)
- 4′ x 10′ and 4′ x 12′ (fewer seams)
- Other specialty sizes available from manufacturers

Best For:

Bedrooms, living rooms, dining rooms
Office spaces, classrooms, and hallways
Ceilings in dry, ventilated interiors
Temporary partitions and non-load-bearing walls
Any space where moisture, mold, or fire-resistance is not a concern

Limitations:

No moisture resistance - not suitable for bathrooms, kitchens, or basements
No added fire resistance - not code-compliant for garages or shared walls
Low sound insulation - doesn't reduce airborne noise between rooms
Can sag over time on ceilings if thinner than 5/8″ is used

Moisture-Resistant Drywall (Green Board / MR)

Green board is a specialized drywall made with a water-resistant core and green-tinted paper facing, designed for use in moderately humid interior spaces. It provides basic protection against moisture but is not waterproof or mold-proof.

Key Features:

Water-Resistant Surface: Treated green paper resists moisture better than standard drywall
Core Composition: Same gypsum core as regular drywall, with light moisture resistance
Finish Compatibility: Can be painted or tiled (in limited-moisture areas)
Standard Thickness: Typically available in 1/2″ and 5/8″ panels
Code Reference: Often accepted by local building codes for non-wet, high-humidity zones

Typical Applications:

Bathroom walls (not inside showers or tub surrounds)
Basement perimeter walls
Laundry rooms and mudrooms
Utility rooms
Garage interiors where minor condensation may occur
Coastal area interiors with elevated humidity

Limitations:

Not mold-resistant - unlike purple drywall, it offers no antifungal additives
Not for wet exposure - should not be used in areas of direct water contact
Inferior to cement board for tile substrates in wet zones
Cannot substitute for vapor barriers or proper mechanical ventilation

Best Practices:

Install with moisture-resistant joint compound and sealing caulk
Use in combination with bathroom fans or dehumidifiers
Upgrade to mold-resistant drywall (purple) or cement board where moisture is prolonged or severe

Mold & Mildew-Resistant Drywall (Purple / Mold Tough)

This drywall type is engineered specifically for moisture-prone environments, where traditional drywall would absorb humidity and promote mold and mildew growth. Mold-resistant drywall features a moisture-resistant core and treated paper or fiberglass face to block fungal intrusion at the surface and within the gypsum.

Key Construction Features:

Core Treatment: Contains anti-fungal additives and moisture-repellent compounds
Face Layer: Coated with mold-resistant paper or fiberglass mat, depending on product line
Durability: Stronger than standard drywall and less prone to sagging or deterioration in damp conditions
Compliance: Meets ASTM D3273 (resistance to mold growth on the surface)

Typical Applications:

Bathrooms and powder rooms (especially ceilings)
Laundry rooms and utility closets
Basement walls and ceilings
Kitchens (behind cabinets, near sinks)
Interior walls in coastal or humid climates
Remediation projects — homes with mold history or water damage

installation Considerations:

Can be painted, tiled, or textured like standard drywall
Should be installed with mold-resistant joint compound and tape
Not a substitute for waterproofing - combine with proper ventilation and vapor barriers
Often used in conjunction with green board or cement board for complete moisture protection

Fire-Resistant Drywall (Type X & Type C)

Fire-resistant drywall is a specialized building material designed to slow the spread of flames and retain structural integrity during a fire. These panels are made with enhanced gypsum cores reinforced with fiberglass and other heat-resistant materials, making them compliant with fire safety building codes.

There are two main types commonly used in residential and commercial construction:

Type X Drywall

Composition: Gypsum core + glass fiber reinforcement
Thickness: Minimum 5/8 inch (15.9 mm)
Fire Rating: 1 hour per layer (when properly installed with framing and joint treatment)
Code Reference: Meets ASTM C1396 requirements for fire-resistance-rated systems

Typical Applications:

Garage-to-house separation walls
Stairwells and fire-rated corridors
Shared walls in multi-family buildings
Utility closets and mechanical rooms
Basement ceilings and egress routes
Commercial buildings requiring 1-hour fire partitions

Type C Drywall (Enhanced Firecode)

Composition: Similar to Type X, but with additional vermiculite or non-shrinking additives
Key Advantage: Maintains integrity longer under direct flame due to controlled shrinkage
Thickness: Also 5/8 inch, but may offer 2-hour fire rating with fewer layers
Use: Higher-risk zones, such as elevator shafts, HVAC chases, data centers, or fire-resistance upgrades

Cement-Based Boards

Cement boards encompass a range of panels made with cement binders and reinforcing materials, offering superior resistance to moisture, heat, mold, and fire. Depending on the composition, they vary in density, weight, structural strength, and application. These boards are non-combustible, dimensionally stable, and do not degrade under moisture - making them ideal for challenging environments where gypsum drywall would fail.

Main Types of Cement-Based Boards

1. Cement Backer Board (e.g., HardieBacker, Durock)

Composition: Cement and fiberglass mesh
Use: Most common tile underlayment
Strengths: Mold-resistant, rigid, thin profile
Best for:
- Shower and bathtub walls
- Kitchen backsplashes
- Laundry rooms
- Wet floor areas (in combination with waterproofing membranes)

2. Fiber Cement Board

Composition: Cement + cellulose (wood) fibers
Use: Structural and decorative board (interior/exterior)
Strengths: Stronger than gypsum, better impact resistance
Best for:
- Exterior cladding and facades
- Fire-rated partitions
- Backing for high-traffic commercial zones
- Soffits, roof eaves, and balcony ceilings

3. Cement Particle Board

Composition: Cement + compressed wood particles
Use: General purpose construction, subfloors, and dry sheathing
Strengths: Heavier but easier to work with than dense boards
Best for:
- Dry or semi-moist interior zones
- Floor sheathing
- Modular partitions and prefabricated wall panels

4. Foam-Core Lightweight Cement Board

Composition: Cement with expanded polystyrene (EPS) or foam beads
Use: Lightweight, insulated building panels
Strengths: Thermal insulation, reduced load
Best for:
- Renovation projects
- Interior partitioning
- Areas where weight is critical (e.g., mobile structures)

5. Autoclaved Aerated Concrete (AAC) Panels

Composition: Cement, lime, sand, and aluminum powder (aerated)
Use: Large-format blocks or panels for masonry-style walling
Strengths: Very light, excellent sound and thermal insulation
Best for:
- Interior or exterior walls in humid climates
- Passive house construction
- Partition walls in schools, clinics, and dormitories

Sound‑Control Panels:

These boards are engineered to reduce sound transmission between rooms or units. They are denser than standard drywall and may include polymer layers or viscoelastic cores for acoustic damping.

Common Use Cases:

Apartment and condo walls (party walls)
Hotels, dormitories, shared living spaces
Home theaters, music rooms, studios
Offices, conference rooms, boardrooms
Schools, classrooms, lecture halls
Clinics and hospitals (for privacy & noise control)

Drywall Installation - A Job for Experts

Even a small drywall project involves a range of technical considerations. Correct framing, joint spacing, screw depth, and load distribution are critical for long-term durability.

Wall Mounting

Professionals install panels horizontally or vertically depending on room dimensions, using laser levels and stud finders to ensure perfect alignment. Panels are staggered to minimize seam visibility and reduce structural stress.

Ceiling Mounting

Ceilings require heavier-duty panels and must be secured properly to prevent sagging. Installing overhead drywall is labor-intensive and physically demanding - best handled by teams with the right tools and lift systems.

Shaping & Custom Cuts

Cutouts for electrical boxes, HVAC registers, and lighting must be precise. Errors compromise the panel integrity and finishing layer. Pros use specialty tools like jab saws and rotary cutters for clean, accurate openings.

Tools & Consumables Used by Drywall Pros

Below are key tools and consumables professionals use - not typically found in average home toolboxes.

Tools

Drywall Screw Gun: Maintains consistent depth and speed.
Drywall Lift: Holds heavy ceiling panels during installation.
Laser Level & T‑Square: Ensures straight, plumb lines.
Rotary Tool / Jab Saw: Makes outlet and switch cutouts.
Panel Carrier: Helps lift and move large sheets safely.

Consumables

Drywall Screws: Correct length and thread type depending on framing material.
Tape & Beads: Reinforce joints and edges.
Backing Supports: Used for patches and structural repairs.

Drywall Repair: Leave It to the Pros

Repairing drywall seems simple - but proper fixes go beyond patching holes.

Common Scenarios:

Nail Pops: Often indicate framing shifts - corrected by rescrewing and reinforcing.
Large Holes: Require structural backing and precise finishing.
Water Damage: Must be fully removed and replaced with mold‑resistant board.

Amateur repairs often result in visible seams, uneven surfaces, or recurring damage. A trained technician evaluates underlying causes and applies industry-standard repair methods.

Pros & Cons – Professional Overview

Each type of drywall offers distinct advantages and trade-offs. Here's a brief breakdown of what professionals consider when specifying material for a project:

Standard Drywall is the most cost-effective and versatile option, suitable for most interior walls and ceilings. However, it offers no resistance to moisture, fire, or mold, and is limited to dry environments only.
Moisture-Resistant Drywall (Green Board) performs better in moderately humid areas such as basements, bathrooms (non-shower zones), and laundry rooms. It resists minor moisture but is not waterproof and should never be used in direct wet zones.
Mold-Resistant Drywall (Purple / Mold Tough) is treated with antifungal additives and ideal for areas with poor ventilation, high humidity, or past mold issues. While it offers superior fungal protection, it comes at a slightly higher cost than standard or green board drywall.
Fire-Resistant Drywall (Type X / Type C) is a building code requirement in certain areas like garages, stairwells, or shared walls. It enhances occupant safety during a fire but is heavier, harder to cut, and requires more precise installation to maintain its rating.Final Thoughts

Drywall isn’t just about screwing sheets to studs - it’s a skill‑intensive process requiring knowledge of materials, techniques, and structural standards. Our expert team ensures long‑lasting, code‑compliant installations and repairs for every space. Looking for reliability, precision, and peace of mind? Leave drywall to the pros.

How We Choose – Professional Criteria

At Trusty Tri Handyman we don’t guess — we select drywall based on project-specific requirements and regulatory codes. Every installation is backed by expert assessment and long-term performance planning.

Here's what we consider during material selection:

Room Function & Environmental Exposure:
Is the area subject to high humidity, potential leaks, or direct water exposure? Will it require fire-rated protection (e.g., attached garage, utility room, shared wall)?
Building Code Compliance:
Local and national codes (such as IRC, IBC, and ASTM C1396) define what drywall types are required in different settings. We ensure every choice meets or exceeds those standards.
Acoustic & Structural Requirements:
For sound-sensitive environments (e.g., apartments, offices, theaters), we may select boards with acoustic cores. For ceilings, we opt for 5/8" boards to reduce sag. Structural use cases may call for fiber cement or impact-resistant panels.
Finish Type & Layering Needs:
Whether the wall is to be tiled, painted, or layered for fire-rating, our choices reflect what works best behind the finish — ensuring durability and code approval.
Longevity & Maintenance Risk:
In areas with recurring problems (like older homes or flood-prone basements), we prioritize materials with proven moisture and mold resistance, saving the client on future repairs.

We don’t just install drywall — we engineer wall systems that last.