A misconception exists in the outdoor hardscapes world. Many homeowners and commercial maintenance groups are told that these areas are NO maintenance or very little maintenance and sealing is not necessary. THAT IS SIMPLY NOT TRUE! The acidic nature of rain erodes the top surface exposing the internal aggregate of the paver, freeze / thaw cycles take their toll, polymeric sand wears out over time allowing weeds to infiltrate, and stains of all kinds penetrate deeper into the surfaces that are not sealed (i.e. grease spills / drips from a BBQ, wine spills, mold / mildew / organics penetrates deeper and sooner into pavers and polymeric sand). I will address each one of these as it pertains to what a sealer can do for the life and beauty of your outdoor surfaces and patio paver systems:
1. Acid Rain: Since pavers are made from concrete just like a driveway, how can you tell the difference between a new driveway and an old driveway? The new one will have a uniform top surface and the old one will have erosional and acid rain damage over time exposing the larger aggregates under the skim finish. Even if a driveway is installed perfectly and it doesn’t crack, the acidic nature of rain, periodic pressure washing, and driving on the surface will wear away the top surface. Pavers stones are made from concrete mixes, so the same happens to paver patios. Sealing the paver system will slow this process of exposing the aggregates inside pavers greatly.
2. Freeze/Thaw Cycles: Believe it or not, mid and southern states go through not many less freeze thaw cycles than northern states that have tons of snow. I could make the case where our climate has much more damaging affects on surfaces then areas that are under snow for most of the winter. When we get winter rains, the water penetrates into the exposed surface and freezes at night. Due to water expanding when it turns into ice, it puts quite a bit of stress on exposed surfaces like pavers, polymeric sands, and concrete. These freeze thaw, cycles over years, can takes it toll, especially on polymeric sand. Sealing these surfaces will limit or prevent water from infiltrating these surfaces and will extend the life of the system.
3. Polymeric sand is still a very new industry. This type of sand was only invented in 1999! The latest versions of polymeric sand have only been around for less than 5 years so they are continually making advancements with this new building material. Don’t get me wrong, it has revolutionized the outdoor building world, but it definitely not a forever thing with the sand lasting up to 10 years. Most systems I see start deteriorating at about the 3-5 year mark, if it is not sealed. The main reason polymeric sand wears out is that it does not have a cement component to the sand. Mortar joints (like you see in brick steps), is a much more durable joint and will last for decades without cracking if the area does not move at all. Unfortunately, just a millimeter of movement on mortar and a crack will develop. This is where polymeric sand comes in. Polymeric sand is flexible and will “move” with the pavers during settling and other small movements without cracking. That’s the good news. Bad news is that without cement in the joint mix, each time the polymeric sand gets wet it will soften and harden again when dry. This wet/dry cycle, over time, especially if you introduce freezing, will fail the top layers of the polymeric sand. Once the top layers fail and create voids where water can sit in the crack, failure happens even faster and now weeds and other organics can start to attack the joint. Sealing these joints periodically will stabilize the joint and limit the amount of water that is able to get into the joint to start breaking it down.
4. Paver patios and kitchens are beautiful when installed and should be used all the time as an extension of the house. Most people are going to barbeque, have outdoor events, and use it without regard to spills, drips or things dropping on the surface (you should use it without worrying!). With that being said, sealing the surface will prevent these small mishaps from being a permanent fixture on your patio. Just like an oil stain is nearly impossible to get out of a driveway, greases from cooking, spilled wine, candle waxes, and growth of mold/mildew over time can be prevented or limited by putting a sealer on outdoor paver surfaces.
What should be sealed?
The types of surfaces that we can seal are:
- Concrete paver patios
Sealers are designed to protect surfaces from wear so anything you walk on or drive on outside should be sealed to maximize the life of the surface, especially paver patio systems and stamped concrete systems. Depending on the application and surface type, we recommend many different types of sealers. These sealers can range from invisible sealers to enhanced sealers to shiny sealers. Not all surfaces will need it, but a grit additive can be added to sealers to create a less slippery surface. These are especially important around pools.