Wall covering products that resist mold and mildew

When my kitchen faucet caused a leak under the sink and mold spotted the drywall behind it, I thought, with what material can I replace the drywall to make it less mold-friendly?  Under the sink is a dark, damp area where water can intrude again.   Searching my local big hardware store, all I came up with was fiberboard that had a melamine coating on one side.

Doing some more research online, however, uncovered several more options.   These are not only for under sinks, but garages, basements, utility closets, porches, and anywhere that moisture can be an issue.  

Using large panels instead of smaller cladding units (tiles, boards, etc.) minimizes labor, opportunities for water ingress, and also dust, which is always an inhalation hazard for the installers and anyone else in the area.  

Interior Cladding

Trusscore is a new PVC product that not only resists moisture, it reduces installation time, labor and cost when compared with drywall.  Trusscore panels are ½” thick, so that they are the same thickness as drywall.  They are so named because of the truss-like structure inside to give them strength with flexibility (they bend enough to facilitate installation inside channels without creasing).  Once you see this product being installed, who would ever want to go back to the labor intensive, dusty, mold-prone drywall process again?  I really like the clean simplicity of this product.  My major concerns with having it in residential spaces were:

• VOCs and off-gassing: how much harmful pollutants will it pass into your indoor air?
• Penetrations, because inevitably, someone will want to hang a picture or shelf on it, and then you have visible, difficult to patch holes in it.  
• What about changing the color? 

However, the company has integrated solutions into each of these problems.  

• Trusscore addresses IAQ here: “Trusscore Wall&CeilingBoard, RibCore, and NorLock products are all low-VOC compliant, including low formaldehyde, meaning it won’t off-gas and ensure a safe and healthy space for occupants. In addition, the installation of Trusscore products does not require potential VOC sources like glue or paint for a finished installation.  Each product has been tested according to the California Department of Public Health (CDPH) Standard Method v1.2 testing standard. This is the leading VOC standard used to evaluate VOC emissions from building products such as flooring, suspended ceilings, insulation, wall panels, paints and coatings, and wall coverings. The CDPH standard is referenced by some of the most widely used green building rating systems and green construction codes including USGBC LEED, CalGreen, and more.”  Still, in a fire, I would RUN out of any area that was covered in PVC...I’d say this is definitely not the material to cover any space where welding or high heat hobbies occur.  Also, I would hesitate install to it in high ambient heat places like Las Vegas or the southwest US (it’s plastic, after all)!  
• Trusscore makes slatwall, which makes it easy to hang things (especially useful in garages and utility rooms)
• All the panels come pre-finished in a durable white or gray coating, and painting guidelines can be found here (Painting requires special primers so that the paint will stick).  The benefit of painting: if you can paint it, you can also patch it!

Duramax PVC Wall Panels are very similar to Trusscore, but they come in 16” widths instead of 48” widths.  They also do not have any slatwall systems, recommending instead to use hangers similar to drywall hangers to permanently hang anything.  The cost of Duramax is less than Trusscore ($2.70/sf vs. $3.60/sf). They do not have any VOC emissions information on their website or MSDS other than protection guidelines against dust generated while installing it.

MSD panels have a variety of natural and futuristic textures (brick, tile, wood, stone, etc.) for a moisture-resistant cladding for interior walls.  The video on this page contains a little bit construction, a little bit artistry as the installers hang the panels and patch the seams to make the brick wall look completely congruent. As an artist, I do like these for the realistic looks they form.  Unfortunately, they are in Spain!

EverBlock and EverWall products are like giant Legos (with these why would you want to “grow up”?).  Everblocks are made of High-Impact Polypropylene Co-Polymer (“no-break”) with UV Inhibitors added for outdoor use.  EverBlocks are recyclable. They don’t offer much insulative quality (R-2 equivalent), but they are hollow and internally reinforced.

Formica lives on!  Formica HardStop has the great variety of colors and patterns of traditional Formica, but instead of the traditional fiberboard backing that is susceptible to moisture ingress, HardStop has a fiberglass backing that makes it more durable and water-resistant. It can be applied to drywall, plywood, and particle board (which are susceptible to water) or to cement or cement board. HardStop panels are thin and flexible like the original Formica, so they do need a structural element for reinforcement behind them.  They also require adhesive (looks messy to me!).

DriCore Smartwall is a similar system that incorporates an insulated layer on the back of the panel.  Very genius, however, the system uses drywall in the panels, and wood cleats to install it and has wood interlocking sections within the panels.  Here is a video on the installation of DriCore Smartwall, which also uses patch material to make a seamless wall.

Exterior cladding

The more I read about building science, the more I see imperfections in “the way we always did it”.  There are many traditional finishes for commercial and residential buildings, but the gold standard calls for a “rainscreen” type structure that applies the cladding to a hidden track system, so that air can reach behind the rainscreen and dry things out.  Think about a rain fly for a tent, or a double roof system.  The air buffer separates water and extreme heat or cold from the exterior of the house, making for a longer-lasting house!  In his article “The Perfect Wall”, building scientist Joe Lstiburek defines the elements of this wall and how they are constructed to resist rain, snow, humidity, air intrusion, mold, heat and cold, etc.

Here are some products that work as rainscreens:

• Nichiha: this company was founded in 1956 in Japan but now has an office and factory in Georgia.  Their cement fiberboard siding comes in architectural panels or premium planks and uses a hidden track system.  It is an upgrade to “Hardy Board” and the many imitations of it, because it “floats” on the track system with that air buffer behind it.
• Ceraclad is a triple-coated ceramic and cement rainscreen with its own installation system. The panels are self-cleaning, with a photocatalytic coating that actually purifies the air!  The coating decomposes car exhaust and other pollutants in the air (NOx and SOx) and turns them into NO3 harmless polyatomic ions leaving the air cleaner.  According to the website, a building with 10,000 sf of external Ceraclad coating is the equivalent of 68 poplar trees!  10 Ceraclad panels are the equivalent purification to 1 poplar tree.  The coating also inactivates viruses and bacteria at its surface. 
• Knight Wall Systems provide the hidden tracks to install your rainscreen.  They have three different types of attachment to accommodate many different types of cladding.  Although mainly commercial, this system could be used for high-end residential homes as well.
• Monarch Metal offers cladding systems with all kinds of finishes including HPL Phenolic, stone, fiber concrete and more.  Their hanging system contains high quality “Z-clips” which are similar to french cleats that allow you to hang the facade without screwing into the face of it, also interlocking panels as you install them.

These are just a sample of ways to get less mold growth in damp areas, relying on 1) materials that don’t sustain mold and 2) siding that incorporates ventilation.  It’s building science at its best!