Mold-Resistant Drywall Review: Pros and Cons

Mold-resistant drywall, also known as greenboard, has become an increasingly popular option for homeowners and builders looking to prevent mold growth in damp areas like bathrooms, laundry rooms, and basements. While mold-resistant drywall offers some advantages over regular drywall, it also has some drawbacks to consider. This comprehensive review will examine the pros and cons of using mold-resistant drywall so you can make an informed decision for your next project.

What is Mold-Resistant Drywall?

Mold-resistant drywall, sometimes called greenboard, gets its name from the green paper covering used on the face and back of the panels. This green paper facing has a water-resistant coating designed to prevent moisture absorption. Manufacturers treat the paper with chemicals and binders that help repel water.

The gypsum core of mold-resistant drywall is also treated to make it more moisture-resistant than regular drywall. Some brands use glass fibers or other additives blended into the core to reduce the absorption of moisture. This helps prevent the inner gypsum layer from breaking down when exposed to damp conditions over time.

By limiting moisture penetration, mold-resistant drywall resists mold growth and deterioration better than plain drywall. When installed properly and combined with adequate ventilation, it provides added protection against moisture damage.

Key Benefits of Mold-Resistant Drywall

Reduced Risk of Mold Growth

The main advantage of mold-resistant drywall is that it helps inhibit mold growth. Mold spores are present in most environments. When excess moisture gets behind drywall, it can allow mold colonies to grow in the damp drywall paper and gypsum core. Mold-resistant drywall’s moisture-blocking additives help prevent mold from taking hold by resisting moisture absorption.

Works Well in Damp Areas

Bathrooms, basements, and laundry rooms tend to have more moisture and humidity than other living spaces. Regular drywall is prone to sagging and deterioration when installed in persistently damp environments. Mold-resistant drywall is designed to withstand moisture better than regular drywall. Its water-resistant surface paper and treated core provide enhanced protection in high-humidity areas.

Longer Lasting

By resisting moisture absorption better than plain drywall, mold-resistant drywall better retains its structural integrity when exposed to dampness over time. The result is drywall that holds up longer than regular drywall when used in wet environments. Homeowners can enjoy improved longevity and avoided costs from premature drywall replacement.

Peace of Mind

For homeowners concerned about potential mold growth, mold-resistant drywall provides added peace of mind. While no material can prevent mold growth indefinitely, especially with excessive moisture, mold-resistant drywall provides an extra layer of protection versus standard drywall. Homeowners gain confidence knowing they’ve taken proactive steps to protect their home’s interior walls against mold.

Potential LEED Credits

Builders and homeowners seeking LEED green building certification can potentially earn credits by using mold-resistant drywall. Its moisture-resisting properties may help projects qualify for Indoor Environmental Quality credits related to mold prevention under the LEED rating system.

Lower Insurance Rates

Some insurance companies offer discounts on homeowners insurance premiums for using mold-resistant building materials. Installing mold-resistant drywall could potentially lower your rates, but policies vary. Contact your agent to find out if you can get a lower rate.

Potential Drawbacks of Mold-Resistant Drywall

While mold-resistant drywall offers important benefits, especially in damp environments, it also comes with some possible shortcomings to be aware of.

Higher Cost

Mold-resistant drywall costs considerably more than regular drywall. It typically costs about two to three times more per sheet. The specialized manufacturing process and materials involved drive up production costs. These costs usually get passed on to the builder or homeowner.

Heavier Weight

The treated gypsum core and thicker facing paper cause mold-resistant drywall sheets to have a heavier weight than comparable regular drywall sheets. This makes the drywall panels a little more difficult to carry and install.

More Difficult to Cut and Install

The heavier weight and strength of mold-resistant drywall also make it harder to score and snap during cutting. Specialized cutting tools and protective gear like goggles are highly recommended to protect eyes from flecks. The panels can also be more challenging to drive screws into during hanging.

Limited Thickness Availability

Mold-resistant drywall is not available in as many thicknesses as regular drywall. Common options include 1/2″ and 5/8″ sheets. Thinner or thicker specialty drywall sheets usually come only in regular drywall.

Limited Size Options

Similarly, mold-resistant drywall comes in a more limited selection of sheet sizes. The most commonly available sizes are 4 x 8 feet and 4 x 10 feet. Larger 4 x 12-foot sheets typical with regular drywall are harder to find.

Fewer Finishing Options

Finished mold-resistant drywall usually requires vapor-permeable water-based primer and paint. This limits oil-based finishing options that could compromise the board’s moisture resistance. Some brands also cannot be skim coated or textured over.

No Fire Resistance

Unlike fire-rated Type X drywall, mold-resistant drywall does not contain additives to improve fire resistance. For fire safety, mold-resistant Type X sheets need to be used.

Can Still Mold if Too Wet

While mold-resistant drywall provides added moisture protection, it is not impervious to mold growth. Prolonged direct water contact or very humid conditions can still enable mold colonies to take hold over time. Preventing water leaks and providing adequate ventilation are still important.

Where to Use Mold-Resistant Drywall

Mold-resistant drywall is ideal for the following damp locations that are prone to humidity buildup or occasional water exposure:

Bathroom walls and ceilings
Shower and tub surrounds
Laundry room walls
Basement walls and ceilings
Spaces around plumbing fixtures
Hot tub surrounds
Entryways and mudrooms
Garages

It is not recommended for dry indoor areas like living rooms and bedrooms where moisture is not an issue. The added cost usually does not provide benefits in rooms with adequate climate control.

In bathrooms, covering all walls and ceilings with mold-resistant drywall is advised. This provides complete protection, especially important around shower and tub areas. For basements, using it on exterior-facing walls that could get some moisture penetration provides better protection than regular drywall.

Popular Brands of Mold-Resistant Drywall

Popular brands of mold-resistant drywall include:

Georgia-Pacific DensArmor Plus – This leading brand comes with a limited lifetime warranty against mold growth. It features a fiberglass-reinforced gypsum core and embedded glass mat facings.

National Gypsum Gold Bond e2XP – Provides enhanced moisture and mold resistance with fiberglass mesh on faces and embedded in the core. Includes a 12-month warranty against mold growth.

USG Sheetrock Brand EcoSmart Panels – Manufactured using sustainable practices and containing recycled content. Treated to score a 10 out of 10 for mold resistance on ASTM D3273 testing.

Continental ProForm MRD – Offers a moisture-resistant gypsum core, embedded fiberglass, and stainless steel facings. Comes with a limited lifetime warranty.

American Gypsum M-Bloc – Lightweight mold/moisture-resistant panels featuring strong glass mat facings. Includes a 5-year limited mold/mildew resistant warranty.

PABCO GLASS FiberReinforced Interior Panels – Combines moisture resistance with built-in fire resistance for mold-resistant Type X drywall applications.

Looking at Mold-Resistant Drywall Brands

With many brand options on the market, here is an in-depth look at some of the most popular brands and how they compare:

Georgia-Pacific DensArmor Plus

Very widely available and popular mold-resistant brand.
Made in the USA and contains 93% recycled content.
Embedded fiberglass mats on front, back, and within the gypsum core.
Core treated with biocide additives to resist mold growth.
Lifetime limited warranty against mold with continued interior use.
Available in 1/2″ and 5/8” thicknesses.
4’ x 8’, 4’ x 10’, 4’ x 12’ sheet sizes.
Paper facings meet ASTM D3273 10/10 score for mold resistance.
Meets ASTM C1658 ratings for increased moisture resistance.
Passes ASTM C473 scores for surface water absorption.
Has superior hardness ratings versus typical drywall.
Cutting requires carbide-tipped scoring tools or circular saw.
Weighs 2 lbs. per square foot for 1/2” sheets.

National Gypsum Gold Bond e2XP

Specializes in extra heavy mold and moisture protection.
Utilizes fiberglass mat facing and embedded fiberglass mesh.
Core incorporates reinforcing glass fibers for strength.
Made with 100% recycled paper facers.
Covered by a 12-month limited warranty against visible mold growth.
Available in 1/2” thickness rated for 24” o.c. stud spacing.
Common sizes include 4’ x 8’, 4’ x 10’, and 4’ x 12’.
Has ASTM D3273 scores of 10 for mold resistance.
Exceeds ASTM C473 standards for water absorption.
Meets ASTM C1629 requirements for humidified deflection.
Withstands building movement while maintaining moisture resistance.
Dense glass fiber core results in very heavy 58 lbs. per sheet weight.

USG Sheetrock Brand EcoSmart Panels

Emphasizes sustainable and recycled manufacturing process.
Contains at least 5% recycled gypsum content.
Facing papers made from 100% recycled content.
Achieves max ASTM D3273 score of 10 for mold resistance.
Has enhanced binders in core and surfaces to block moisture.
Exceeds ASTM C473 standards for water absorption.
Covered by a limited 12-month mold resistance warranty.
Common panel sizes include 4’ x 8’ and 4’ x 10’ in 1/2” and 5/8” thicknesses.
Weighs 2.2 lbs. per square foot for 1/2″ sheets.
USG also offers lightweight Ultralight Mold Tough panels.

Continental ProForm MRD

Combines moisture resistance with sound deadening properties.
Gypsum core treated with glass fibers and additives.
Embedded fiberglass mesh helps prevent cracks.
Covered with microbial resistant stainless steel facings.
Achieves a 10 out of 10 score on ASTM D3273 mold testing.
Includes limited lifetime warranty against mold growth.
Offered in 1/2″ thickness for 24″ o.c. stud spacing.
Common sheet dimensions of 4’ x 8’ and 4’ x 10’.
Steel facings eliminate need for corner beads during finishing.
Special cutting tools needed to cut strong steel facings.

American Gypsum M-Bloc

Economical mold and moisture resistant panels.
Paper facings embedded with fiberglass strands.
Lightweight gypsum core treated with biocides and wax emulsions.
Achieves scores of 10 out of 10 on ASTM D3273 mold testing.
Exceeds requirements of ASTM C1629 for humidified deflection.
Includes a 5-year limited warranty against mold growth.
Available in 1/2” and 5/8” thicknesses.
Common sheet sizes include 4’ x 8’, 4’ x 10’, 4’ x 12’, and 4’ x 14.’
Weighs 1.55 lbs. per square foot for 1/2″ sheets.

PABCO GLASS Regular and Type X

Combines mold resistance with Type X fire resistance.
Good for bathrooms, kitchens, garages where fire safety is also important.
Embedded glass mats provide moisture and mold resistance.
Type X gypsum core offers 1-hour fire resistance rating.
Achieves a 10 out of 10 on ASTM D3273 for mold resistance.
5-year limited warranty against mold growth included.
Available in 1/2” Regular and 5/8″ Type X thicknesses.
Common panel sizes include 4’ x 8’, 4’ x 10’, and 4’ x 12.’
Cuts easily using standard drywall tools.
Weighs 2 lbs. per square foot.

How Much Does Mold-Resistant Drywall Cost?

Due to its specialized manufacturing and materials involved, mold-resistant drywall costs significantly more than regular drywall. On average, expect to pay around $1-$1.50 per square foot for mold-resistant 1/2″ drywall panels. By comparison, 1/2“ regular drywall averages about $0.50 per square foot.

So for a common 4 x 8-foot sheet size (32 sq.ft.), mold-resistant boards cost $32-$48 per sheet on average versus just $16 for typical drywall. The premium for enhanced mold/moisture resistance is around 2 to 3 times higher.

Several factors affect the pricing:

Brand – Premium brands like DensArmor Plus tend to cost more than value brands.
Thickness – Thicker 5/8” boards that offer more strength run $1.20-$1.80 per square foot.
Quantity – Buying full bunks (20-30 sheets) typically provides a discount versus small quantities.
Supplier Type – Big box stores charge more than building material suppliers.
Transportation – Delivery fees can add cost if not picking up locally. Regional pricing varies.

It’s a good idea to get quotes from 2-3 local suppliers before purchasing. For professional installation, the extra labor and materials costs of mold-resistant drywall typically add $2-$3 per square foot to drywall finishing pricing.

Tools Needed for Cutting and Installation

While mold-resistant drywall installs much like traditional drywall, its properties do require some specialized tools and techniques:

Carbide-tipped or fiber-cement scoring knife – The heavy-duty blade provides clean cuts through the glass fiber facings. Standard utility knives work for occasional cuts, but a proper scoring tool is best for volume cutting.
High RPM power drill – Fitted with a drywall cutting bit, the drill enables clean circular cuts around openings and penetrations. Match the drill speed to panel hardness.
Dust mask – Helps filter out glass fiber particles when cutting drywall. Safety goggles also recommended.
Proper fasteners – Corrosion-resistant screws specifically designed for mold-resistant sheathing provide optimal fastening strength. Ring-shanked drywall nails also work.
Premium joint compound – Setting-type joint compounds create harder seams and better adhesion than drying-type compounds. Mold-resistant varieties are available.
Silica dust vacuum – Used when sanding between coats of joint compound. Helps contain fine gypsum and fiberglass dust.

Take care when cutting and drilling to keep panels firmly supported and avoid breathing dust. Follow all manufacturer safety guidelines closely, have adequate ventilation, and use dust collection tools whenever possible.

Installation Tips and Best Practices

Proper installation technique is important to gain the full benefits of mold-resistant drywall and avoid future problems:

Check that wood framing lumber moisture content is below 15% prior to installation. Use a moisture meter if unsure.
Allow adequate spacing between panels when fastening to framing. 1/8″ gaps for 1/2″ drywall; 1/4″ for 5/8” drywall.
Drive fasteners 1″ from panel edges and no more than 8″ apart across faces and around openings.
Stagger panel end joints between rows. Do not align joints unless supported by framing.
Make sure fastener heads seat firmly just below paper surface without tearing facings.
Use paper joint tape embedded in setting-type compound to reinforce seams and inside corners.
Fill screw depressions fully with joint compound and let dry between coats.
Sand between finish coats using 180 grit or higher sandpaper. Avoid scuffing paper facings.
Maintain ambient temperature and humidity per manufacturer instructions during installation and drying.
Allow panels and joint compound to fully dry before painting or texturing.
Apply vapor-permeable primer and latex paint made specifically for mold-resistant sheathing.

Following the manufacturer’s recommended installation methods is highly advised to gain the best mold resistance. Taking shortcuts risks compromising performance.

Maintaining Mold Resistance Long-Term

To keep mold-resistant drywall protecting your interior walls and ceilings long into the future:

Control Moisture Levels

Prevent excess humidity and dampness through proper ventilation and climate control. Run fans and dehumidifiers as needed. Fix any plumbing leaks right away.

Clean Up Spills Quickly

Don’t allow water splashes or spills on walls to remain. Wipe up promptly and dry the area.

Use Exhaust Fans

Run bathroom and kitchen exhaust fans regularly to remove moist air. Vented fans are most effective.

Allow Proper Drying

After cleaning walls or when humidity is high, make sure panels fully dry out before sealing up a room.

Inspect for Leaks

Periodically check for hidden roof or plumbing leaks that could allow moisture behind walls. Catch issues early before major damage occurs.

Check Sealants

Reapply caulk and grout around tubs, showers, sinks, and fixtures when needed to prevent water intrusion.

With proper installation and maintenance, quality mold-resistant drywall can protect interiors from mold and moisture damage for many years of use.