Why are Pressure Treated Wood Stairs and Decks Slippery?

If you live in a single home that has a backyard, chances are you either have or are planning on building a patio or deck. In most areas of the country the most popular construction material for that outside structure is pressure treated wood.

What Is Pressure Treated Wood?

Pressure treated wood is a readily available construction material used for all sorts of outdoor construction projects including stairs, decks, pergolas and patios. Typically made of southern yellow pine. Its natural look, price, and durability make it a popular choice for outdoor use.

The wood is called “pressure treated” because of the process in which the wood becomes protected from rot and decay. Specifically, the wood is placed into a pressure chamber and the air is removed from it. Then, various chemicals are pushed into the wood depending on the type of protection from weather, insects and decay that is desired. After the chemical treatment, the wood is set to the side to dry before it can be sold.

FACTOID:  Pressure treated wood should never be used for indoor construction because of the chemicals used to treat it. Also, cutting, burning, and disposing of it should be done safely because the chemicals can be released into the air.

Pressure treated wood is excellent for outdoor construction because the treatment allows it to survive outside for up to 30 years. The chemicals absorbed into the wood not only protect it from the elements, but also help prevent organisms from causing damage, working as a pesticide to stop insects from eating away at it. Most pressure treated wood also retards damage from fungi, algae, mold, or other growing organisms.

While the pressure treated wood greatly slows the decay of the wood, it still shares one thing in common with all types of construction wood: it can get slippery.

Why Does Pressure Treated Wood Get Slippery, Even in Warm Weather?

Water may not be able to easily seep in, but that doesn’t stop the water from having a big effect on pressure treated wood. Naturally, when it rains, your deck, stairs, or ramp will get wet. It takes time for the water to dry up, especially when not in the sun, and that wetness is a breeding ground for fungi, algae, moss, and mold. The shady areas on your deck, porch or stairs are even more likely to have these sorts of organisms growing because the wood will be dark and damp longer, and dark damp areas are where things like mold grow best.

You’d think the slipperiness on the wood would come from the water itself; however, it’s actually these organisms that grow on the wet wood that cause the slipping!

Cleaning Your Deck Regularly To Make it Less Slippery

You can temporarily reduce the slip and fall risk posed by organic growth on pressure treated wood with a good scrubbing and power washing. Because the primary source of the slipperiness is the algae, moss or mold that’s growing on the wood, you can remove the surface layer of organic growth by scrubbing down the affected area and power washing it.

Power washing can temporarily remove mold, mildew and other slippery organic material from pressure treated wood.

The mechanical cleaning removes the top layer of mold but won’t eliminate the organic gunk deeper in the wood that generates new growth.

We have found that some DIY blogs recommend the use of a mixture of soap and oxygen bleach to remove mildew and mold from pressure treated wood. However, environmentalists have expressed concerns about the combination of oxygen bleach cleaners and the chemical compounds found in pressure treated wood. As reported by Brian Rader, the Pollution Prevention Specialist for San Juan County Washington,

Oxidizing agents, even our humble sodium percarbonate, (e.g. OxiClean) can react with some types of pressure treated wood to release chromium and arsenic into the environment. These chemicals are toxic to people and aquatic life at fairly low concentrations. This is exactly what we want to avoid putting into our lakes and harbors.

To be environmentally conscious while still decreasing the slipperiness of you pressure treated stairs or deck, we’re talking about a fairly heavy and regular schedule of scrubbing and power washing. For some this is an acceptable solution. For others, this maintenance might be too difficult to continue over time.

What About Chemical Treatments to Inhibit Organic Growth on My Pressure Treated Deck?

Oftentimes, people will take an extra step to protect the wood on their deck and use a water-repellent sealant to stop moisture from seeping into the wood. While this does protect the wood from damage, it can make the wood slicker. Rain won’t be absorbed by the wood because of the sealant, and it’ll instead rest on top, making the surface dangerous to walk on.

There are anti-slip sealants that can be applied, but none are fully effective against nature and most degrade fairly quickly. The ones that work the best often have premium prices, and require regular maintenance that can be costly.

Whatever kind of sealant is used, a pressure treated wood surface will need a re-coat every couple of years. Nobody’s perfect, and it could be easy to forget about doing this. Over time, organisms could begin to grow on the deck from the forgotten care.

Are There Non-Slip Paints That Can Be Applied to Pressure Treated Wood?

One of the features that draws people to pressure treated wood is its natural look. However, others may choose the wood for its low price and will decide to paint over the wood instead. The painted surface will be slick, and again, even the slightest bit of wetness can create a slippery area.

If you’re inclined to paint your stairs or deck you can improve traction by adding grit to specific types of deck paint, or by purchasing and applying grit paint, like we sell here. Think of grit paint as sand suspended in the paint creating a rough, textured surface. Grit paint offers improved traction, but at a price. First, painting a deck properly takes a lot of preparation, and if you don’t take care when preparing the surface the paint may not adhere well.

Second, in the winter you can’t use a shovel to clear any snow, as you’ll scrape the paint or wear the layer of paint from the high points of the grit. Finally, if you choose a tougher epoxy-based grit paint, it can be very expensive with a gallon of non-slip epoxy paint costing upwards of $100.

Non-Slip Stair Treads and Deck Treads

Pressure washing, chemical treatments and grit paint can work in the short run but they can be difficult and time consuming to employ, require regular maintenance, and are ineffective if you live in a part of the country where frost, snow and ice are regular visitors.

Non-slip treads and deck treads, whether our aluminum version with a lifetime residential guarantee, or our competitors’ plastic and fiberglass variants, provide the highest level of traction with least amount of maintenance.

The downside to most treads is that they don’t always blend in visually with the pressure treated wood and if you’ve got an expansive area of slippery deck, the number of treads required can make it an expensive proposition.

We’ve done our best to minimize the visual impact of our non-slip products, especially our deck treads that come in three earth tone shades that blend into most colors of pressure treated decking. While obviously noticeable, they aren’t distracting and most importantly, provide a level of safety and livability that the alternatives do not.

No matter what method you choose to reduce the slipperiness of your pressure treated wood, it’s important to remember that the cost of an avoidable slip and fall will be far more in dollars, recovery time and lost opportunity then your effort to prevent them.

You’ve already saved money by choosing pressure treated wood for your deck, ramp or stairs. Invest a little of that money into making your home safer for loved ones and those who visit.