For most contractors, maintenance of hardscapes is something that is avoided altogether or just foreign to many installers. But for the customer, most hardscapes done right by a quality professional are nothing short of an investment. Considering this, it’s simply not practical for the majority of clients to rip out and redo a project when the walkway/patio/driveway starts to show its age. Yet, to restore the original hardscape typically only costs the customer about 15% to 20% of the original investment. As a result, offering quality hardscape maintenance is a way to diversify your services and take care of your customers and projects in the long term. It also presents an opportunity to perform maintenance and restoration services to other customers that you didn’t originally install. This article explains the dynamics of maintaining and restoring hardscape in both situations.
Failing joint sand (easily identified by growing weeds, moss, black mildew, and ants hills or insects in the joints) along with all other joint contents are removed by pressure washing with a concrete turbo nozzle and a unit with at least 3000psi and a 3gpm rating. We prefer units around 4000psi and 4gpm rating. The more powerful the unit, the less time it takes to complete the job. Joint contents are broomed and shoveled off of the surface before a final rinse down is completed. Repairs to pavers and edging can be made at this point during the drying time.
Once the surface is dry, new high-performance polymeric joint-sand is swept into the joints with a stiff bristled push broom. The technology in this product eliminates some of the common issues with traditional poly sand like surface hazing and soft joints, and is easier to install. (See The Shopping List.) Using a back and forth motion, sweep the sand to ensure that each joint is filled to the entire depth of the paver. Leave only a small amount of excess behind on the surface, and then compact using a roller compactor or plate with rubber pad. This process is repeated until the joints are completely full and do not compact down any further.
Compaction is a vital step when installing polymeric sand. Compacting the sand down removes voids and locks-in the polymeric sand. While skipping this step may save you time, you’ll also risk having joints that settle, crack, and break over the long term. We recommend the use of roller compactors since this tool will increase the overall strength and performance of the joint sand over the long run. Unlike traditional plate compactors, rollers can compact pavers, slabs, and natural stone, making them a worthwhile investment. (See The Shopping List on page 26.)
After a clean final sweep, use a leaf blower at its lowest setting to blow away any excess polymeric sand residue and to finish off the joint. Angle the blower at roughly 30 degrees to ensure you’re blowing air across the surface and not blowing sand out of the joints. Sand is then wet in with a hose on a shower setting to activate polymers. Shower your pavers to activate and harden the sand. Use the light pressure of a shower nozzle to gently saturate the joint sand just until the water stops soaking into the joint.
The amount of water you use is a critical element to sand installation. Using too much water can cause the joint to over-saturate and result in polymer washout spreading sand onto the surface of the pavers. This is both hard to remove and an eye sore. Conversely, failing to use enough water leads to incomplete polymer activation, weak bond, washout, and less resistance to infestation by weeds and ants. It can leave your joint powdery, fragile, and susceptible to cracking under slight distress.
After showering pavers with water, give them time to set—no matter where they were installed. Avoid most foot traffic on walks and patios for at least 24 hours. If the pavers are for a driveway, tell the client to wait 48 hours before driving over them.
Also avoid any additional water hitting pavers. Haste makes waste, so check the weather and plan accordingly. If rain shows up before or shortly after finishing your installation of poly sand, you could potentially have quite a mess on your project. A hard rain could require you to start over. Installing polymeric sand when the surface of your pavers is still wet or even damp can also cause unwanted sticking of the polymers to the surface, which can make them difficult to remove. Product information recommends at LEAST 90 minutes before a rain shower. But we like to say three hours minimum from our experience. If an all day rainstorm is predicted the following day, reschedule the job.
The Shopping List
Here are some of Bianchi’s product recommendations:
- Don’t purchase the cheapest polymeric sand. Some sand manufacturers use lower-quality polymers in the sand mixture to cut their own costs. While this will save some money in the short term, you’ll just wind up needing to go back to redo the work or clean surface haze. This also takes a hit on your reputation when the job doesn’t come out as planned and customer expectations are not met. The polymers that last longest perform best and require less attention to technique. They cost a little more, but are worth the $10/bag difference. We recommend the use of Techniseal NextGel Polymeric Joint Sand available in a wide variety of colors.
- We recommend roller compactors over traditional plate compactors. ESI has the EVPC120H and Weber manufactures both the VPR 700 and the VPR 450.
- For permeable installations, Azpects EASY Joint, a resin based joint material, instead of #9 clean stone, is a permanent joint solution which remains permeable over the life of the hardscape. Minimal maintenance with a power washer every couple of years is all that is required. For application methods, click here.
- When doing a new paver installation, we use Alliance Gator Base interlocking panels over a pea stone or washed mason sand bed to help prevent future heaving or sinking of pavers. We also use Alliance Gator Effloresence Cleaner to clean pavers.
- To remove sunken pavers without damaging them, we recommend using a Quick-E-Paver Popper. And when replacing edge restraint, we like using Quick-E-Hybrid Edging for performance and resistance to freeze/thaw movement. It can be installed using traditional ten-inch steel spikes, or its own system depending on the type of base you are securing into. Using this edging on new installs can help avoid the need for replacement later on. Both products were actually developed by Phil Bahler in 2007 after years of installation experience with Bahler Brothers. The Quick-E tools (as well as products from other manufacturers) can be found at the separate company Phil created, Pave Tool Innovators, based in Vernon, CT.
Prior to installing new polymeric sand, pavers may need some repairing, adjustments or new edge restraint. The ideal time to do this is after you have cleaned and blown out all the joints on the project. Areas of settlement are the most common paver repair. Try to remove sunken pavers without damaging them. (See The Shopping List on page 26 for tools.) A pea stone aggregate is best when filling in and leveling under the pavers before they are tapped back into place. Be sure to maintain pitch in at least one, but preferably two directions, when making these repairs. Otherwise, the puddled area you intended to fix will be moved over to another location of the hardscape. This can be tricky, but with practice it becomes much faster over time.
Edge restraint can rise up out of the ground little by little each year due to freeze/thaw cycles and need replacing. When installing, excavate along the edges of the pavers enough so that the highest point of the edge restraint is at or below the half-way point of paver depth.
For projects you are designing and building new, using base interlocking panels under the pavers, but over a pea stone or washed mason sand bed, will prevent heaving or sinking of pavers down the line. These base panels allow you to reduce the amount of excavation required when basing your project. This saves a great deal on time, hauling and material. Also specifying weather-resistant, high performance edging on new installs will keep you from replacing edging later on. When using top quality materials, you eliminate a great deal of maintenance and repairs down the road.
Cleaning & Sealing
It is recommended by most manufacturers to wait six months to a year before cleaning and sealing pavers. This allows excess minerals, called efflorescence, to surface before the cleaning and sealing take place. For existing hardscape, sealing is generally recommended every three to five years. Cleaning with a hardscape cleaner or efflorescence remover is necessary prior to any sealer being applied, or for a general cleaning. Muriatic acid is also recommended at a ratio of 16:1 to 22:1 parts water to cleaner because it is economical and highly effective. This is necessary to free the surface of any ground-in dirt, efflorescence, or oxidation, and to open the concrete pores to “accept” the new sealer that will be applied.
Apply cleaner using a watering can from the lowest point of the pavers to the highest point. Don’t let the cleaner dry on the surface. After a dwell time of a few minutes, rinse with a rinse nozzle on your pressure washer or use a hose. Now, with a 40 degree nozzle tip no closer than six inches from the surface of the pavers, power wash to remove all of the contaminants the cleaner loosened. This time, start at the highest point of the project and work your way down. Do small square sections at a time to avoid leaving stripes from areas that were missed. This is critical if you will be sealing afterward. Joints that are sound should not be affected much from pressure washing. If they are, a joint re-sanding job (as detailed earlier) is in order. You may also need some rust remover (oxalic acid) to remove stubborn rust stains, and/or chlorine solution (diluted pool shock in a 2:1 ratio of water to chlorine) to remove organic staining from leaves, acorns, maple keys, mildew, etc.
Once cleaned, the surface can then be sealed with either a natural-look, wet-look, or clear-look water-based sealer. This leaves a water resistant, luxurious finish to prevent future wear, staining, dirt, and contamination. There are two types of sealers: penetrating; and film-forming. Penetrating sealer leaves no film on the surface, but absorbs and gives the paver a stain repellent property. The look of the paver does not change, but water and other liquids will bead up if the sealer is intact. However, penetrating sealer doesn’t prevent erosion to the degree film-forming sealers do. Penetrating sealers are most commonly applied to natural stone, wet-cast slabs, and can be used with traditional pavers. Film-forming sealers are used more often because they offer more erosion protection and leave a semi-visible sheen on the surface. They offer the stain protection mentioned, but add an aesthetic element as well. However, film-forming sealers should not be applied to natural stone or wet-cast slabs.
Sealer should be applied with an airless pump sprayer, a backpack sprayer, or a motorized unit that maintains pressure via battery power. A broad tip 1gpm fitting is ideal to spray large areas and maintain a wet edge while spraying. Mask off any areas you don’t want sealer to overspray onto, especially glass, stainless steel, vinyl siding, or painted surfaces. Sealer should be applied quickly so it all dries uniformly to avoid overlap marks in the finished product. This eliminates back rolling if done properly.
Do not attempt to roll on sealer with a paint roller and paint tray unless the area is very small. And do not attempt at all if it is hot and sunny out. The sealer will dry too quickly and will inadvertently form overlap marks. Avoid moisture and most foot traffic on walks and patios for about 24 hours. If the pavers are in a driveway, wait 48 hours before driving over them.
The main benefit to sealing pavers is to prevent the surface erosion that takes place over the years from rain and the elements. All concrete, whether it is pre-cast products like pavers or poured-in-place like sidewalks, will erode over time. Larger aggregates and stones become visible and the paver becomes much rougher than when it was smooth and new. Once this happens, it cannot be undone. Sealing pavers professionally every three to five years with a film-forming sealer will prevent this from occurring.
Sealing pavers also keeps them cleaner by preventing surface contaminates (like moss or mildew) from becoming embedded in the concrete pores over time. Sealers also allow for easy routine sweeping and rinsing, and helps to further stabilize the joint sand, adding longevity to the hardscape project and protecting your customer’s investment—and your reputation—for years to come. As a result, some installers include sealing with all the jobs they build. Others offer the service six months to a year later. (At my company, we tend to do the latter.)
Restoration and maintenance of hardscapes is a niche within a market, virtually untapped. There are millions of square feet of pavers in the ground to date. Sure, some projects are so bad you’ll need to start from scratch, but the majority just need some expert TLC.
Bianchi heads the Hardscape Cleaning & Maintenance Division of Bahler Brothers in South Windsor, CT. An employee of Bahler Brothers since 2014, he has been working with pavers, sealers, cleaners, and the chemical aspects of hardscape maintenance and concrete coating for the last eight to 10 years. During that time, he has completed roughly 775 hardscape maintenance jobs. Find his hardscape blog entries here.
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