Decks give you more living space. Decks also add value to your home on resale. In fact, a deck may be considered a required feature depending on your home's size and location. I once considered converting a deck to a finished family room and the appraiser told me for the size of the house, a deck was required while a family room was not. We kept the deck.
You have many choices today for deck materials, from traditional wood to composites that require less maintenance. If you already have a deck you love, this article will give you recommendations for cleaning and sealing your deck to insure many more years of use. If you are considering adding a deck to your home, there is a companion article, Deck Building Basics, with an overview of things to consider when planning your deck and picking materials.
Cleaning Your Deck
Cleaning wood decks (new and existing) opens up the wood’s pores and sealers can penetrate up to 25% deeper. The ideal temperature for cleaning a deck is 60 to 70 degrees Farenheit. At this temperature, deck cleaners won't evaporate too quickly and sealants can seep into the wood versus evaporating too quickly.
When using any type of chemical, whether a cleaner or sealer, it is a good idea to water the surrounding greenery first and cover with plastic in a way that doesn’t prevent air from circulating.
There are numerous ways to clean your deck and lots of controversy about pressure washing which can damage your deck if not done correctly:
- Pressure washing – cleans with high pressure streams of water to remove algae, mildew and other stains. The wood fibers already weakened by UV rays can be stripped and the wood must be sanded before the sealer is applied.
- Chlorine bleach – or sodium hypochlorite is NOT recommended. It’s great for killing germs but wreaks havoc on wood by removing it’s natural color, destroying wood lignin, corroding deck hardware and it can kill the surrounding vegetation.
- Oxygen bleach – doesn’t remove the wood’s natural color and is non-toxic to plants. It is safe on all woods except redwood which should be cleaned with oxalic acid. For step-by-step directions to follow this process visit Ask The Builder.
Sealing Your Deck
Unprotected wood is vulnerable to ultraviolet rays and water in any form. Wood that isn’t sealed is subject to excessive shrinking and swelling which can result in cracking, cupping and twisting, which in turn causes nails to pop. Water that penetrates untreated wood can also accelerate wood rot. You have numerous choices for sealing your deck:
- Sealants (oil based vs synthetic)- traditional ones contain wood protecting resins made from natural products (tung oil, linseed oil, etc.) Unfortunately these oils are also food for mildew and algae. Synthetic water repellants don’t contain such food.
- Stains – don’t chip like paint. They come in semi-solid and solid (not recommended) colors similar to paint. The stain is absorbed into the wood and the pigment particles absorb and deflect the UV rays and help protect the wood.
- Paint – requires more maintenance than stains or sealers. It chips and sometimes bubbles (if wood absorbs moisture from below) rather than wearing away smoothly like stain. Unfortunately once painted, it is very difficult (stripper may work or you need to remove and sand boards on all sides) to change color or switch to a stain.
IMPORTANT – While numerous deck stain and sealer brands like SuperDeck and Sikkens, get good reviews, the best advice is to purchase a quality product at a paint store. Quality products may cost more initially but they save you money with better, longer lasting coverage. Products that cost less often require an extra coat of stain or may require more frequent applications.
If you're tired of the work and cost to maintain your deck, it's time to consider replacing all or part of your deck with composites that need far less maintenance. Learn about new deck materials in Deck Building Basics.
Hi Tina, love your articles! I have a question for you.. the bottom 7-8 inches of my “sawdust” siding is rotting behind the trim board. I only have about 8″ of roof overhang, no gutters (will be adding ), the parallel deck boards are butted up against the trim, and the trim board ( 4″ ) was sitting directly on deck board. I’m guessing splash was a big contributor. I am adding gutters and replacing trim board with an 8″ one. Should the deck board nearest house be ripped so there is space between it and house? Should trim board rest on or slightly above deck board? Should I caulk bottom of trim board as well as top?
Laurie, Sounds like your deck wasn’t installed properly … meaning they didn’t use a ledger board. You’re correct about splash back being a contributor but it’s also true that water will get behind your siding and needs a way to drain properly. Wood rot was one of the biggest problems my handyman business dealt with, so I’ve got an article on deck repairs. The concept is you need to use flashing that’s installed behind the siding, and wraps around the ledger board so that water can flow directly to the ground without soaking into wood along the way. If you need more help, email me.