Paver Cleaning in Naples, FL

A paver cleaning takes off the dirt, grime, algae, mold and tough stains that make a driveway look older than the house. The industry's method for concrete pavers is written down in ICPI Tech Spec 5, “Cleaning, Sealing and Joint Sand Stabilization of Interlocking Concrete Pavement,” the technical note of the Interlocking Concrete Pavement Institute, now part of the Concrete Masonry and Hardscapes Association.

ICPI's procedure is chemistry first, water second. Efflorescence cleaners go on “with a low pressure pump spray 30 to 100 psi,” sit for the time the product calls for, and are rinsed with a high-pressure sprayer that runs “between 1,000 and 4,000 psi” at “between 2 and 6 gallons/minute.” The nozzle matters as well: “A nozzle that creates a wide spray enables a large area to be covered efficiently and prevents sand from being washed from the joints. A low angle of attack from a wide nozzle spray will also reduce the risk of dislodging joint sand.” And the finish is plain water: “The final rinse should be water only. A large amount of water is more important to rinsing than high pressure.”

Water alone is not a cleaning. Techniseal, a sealer manufacturer, answers the question directly in its product guide: “A simple water jet will not remove grease stains and will not dissolve efflorescence, a whitish salt that accumulates at the surface of pavers.” ICPI writes that many cleaners effective in removing dirt and efflorescence are “a mix of detergent and acid,” and warns that “cleaners with strong acids will change the color of the pavers slightly,” which is why “cleaners should be tried on a small area to test results and any color changes.” Work starts at the bottom of the pavement and runs up the slope in sections, because “by working up the slope, cleaning fluids will drain down the pavement,” and “sediment or cleaners allowed to pond in low spots may stain the pavers.”

Efflorescence: the white haze that is not dirt

ICPI: “Efflorescence is a whitish powder-like deposit which can appear on concrete products.” It forms when calcium hydroxide from the cement migrates to the surface and reacts with carbon dioxide in the air to make calcium carbonate. It “does not affect the structural performance or durability of concrete pavers.” It “may reach its peak in as short as 60 days after installation,” may “remain for months,” and some of it may wear away. When it needs removing, ICPI points to “a proprietary efflorescence remover” whose acid “is buffered and blended with other chemicals to provide effective cleaning without damage to the paver surface,” with the result checked “after letting the area dry for at least 24 hours.”

The word “pavers” covers three materials on this page, and the chemistry that is right for one can etch another.

Say what the surface is made of when you ask for an estimate. A travertine pool deck and a concrete paver driveway follow different rulebooks. The roof over that patio gets its own rules on the roof cleaning page.

After the deep clean, 239 Exteriors applies a premium sealant to protect against stains, UV damage and weed growth between joints. ICPI describes the mechanism: “Sealers reduce the intrusion of water, stains, oils and dirt into the paver surfaces,” and “most sealers change the appearance of the paver surface by darkening it and enhancing the surface color.”

Film-forming: the wet look

Acrylic sealers “can be solvent or water based. They enhance paver colors well and create a gloss on the surface. Acrylic sealers provide good stain resistance.” They “generally last for a few years” before re-coating, and “when they become soiled or worn, pavers with acrylics can be easily cleaned and resealed.” ICPI keeps them off “high abrasion areas such as industrial pavements or floors.” Urethanes “produce a high gloss and enhance the color of pavers.”

Penetrating: the natural look

Silane and siloxane sealers soak in rather than coat. “They initially enhance colors and produce a flat, no-gloss finish on the paver surface,” and they breathe: “A hydrophobic barrier to moisture is created, preventing moisture from entering but allowing the concrete to” breathe, as ICPI puts it, and release water vapor. Two ICPI lines read as if written for this coast: penetrating sealers give “additional protection of pavers subject to deicing salts or salt air,” and “they are also useful around pool decks to minimize degradation from chlorine.” Their limit: “Silanes and siloxanes do not resist penetration of petroleum stains unless they have additives specifically for that purpose.” Techniseal labels its (iN) Natural Look Protector “Penetrating: Will not make surfaces more slippery.”

ICPI also names what not to put on pavers at all: “Sealers not recommended for use with pavers are alkyds, esters, and polyvinyl acetates. Epoxies and silicones are generally not used on concrete pavers.” Which family suits your surface, gloss or flat, depends on the material, the traffic and the look you want, and it is settled in the estimate conversation.

A sealer that turns white is usually a moisture story, and ICPI lists the four conditions behind it.

• “The surface and joints are not dry.”
• “The pavers have not had an adequate period of exposure to moisture,” which is the new-paver case: the concrete is still pushing out efflorescence.
• “There is a source of efflorescence under the pavers (i.e, in the sand, base, or soil) moving through the joint sand and/or pavers.”
• “The sealer is not breathable, i.e., does not allow moisture to move through to the surface of the paver and evaporate.”

Cloudiness has the same roots: “If the base under the pavers drains poorly, the sealer is applied to saturated sand in the joints, or is applied too thick, the sealer can become cloudy and diminish the appearance of the pavers. In this situation, the sealer must be removed or re-dissolved.” The prevention is in the preparation. ICPI: “The cleaned surface must be completely dry prior to applying most sealers. Allow at least 24 hours without moisture or surface dampness before application.” That one sentence is why, for most sealers, a clean and a seal are not the same afternoon, and why a wet-season storm can move a sealing day.

New pavers and the 60-day rule of thumb

You will read that new pavers must wait 60 or 90 days before sealing. ICPI publishes no such calendar. What it says is that efflorescence “may reach its peak in as short as 60 days after installation,” that sealing pavers that “have not had an adequate period of exposure to moisture” is one of the whitening causes above, and that if installation “takes place during dry period of the year, the next cycle of wet weather may sometimes be necessary for efflorescence to materialize.” The wait is a moisture condition; any fixed number of days is a particular paver or sealer maker's instruction, not an industry rule.

Slip

ICPI: “Be careful not to over apply the sealers such that the surface becomes slippery when cured,” and “adequate slip (foot) and skid (tire) resistance of concrete pavers should be maintained with properly applied joint sand stabilizer or surface sealers.” Slip-resistant additives exist as named products from sealer manufacturers, and ICPI says the sealer maker “should be consulted concerning slip and skid resistance performance characteristics under wet and dry conditions.” A pool deck is where the question gets asked, and it belongs in the estimate.

Drying, traffic and re-coating

ICPI: “Prevent all traffic from entering the area until the sealer is completely dry, typically 24 hours.” Techniseal's table for its paver protectors reads “Pedestrian: 24 hrs” and “Vehicular: 48 to 72 hrs,” so the cars stay off the driveway longer than feet stay off the walk. Wind matters too: for sprayed applications “the wind should be calm so that it does not cause an uneven application, or blow the sealer onto other surfaces.”

Re-coating is a matter of wear rather than a calendar. ICPI commits only to “reapplication after a period of wear and weather,” depending on “the use, climate, and quality of the sealer.” Techniseal is explicit that more is not better. Asked whether a fresh coat can go on every year, its guide answers “No,” explains that its protectors “are made to last several years,” that too much product applied too often “will create a buildup” that “could lead to the whitening and peeling of the film on the surface,” and that “normally, it is recommended to wait at least 2 or 3 years before recoating.” That is Techniseal's interval for its own products, not a universal one.

The joints are the weak point of a paver surface, and the wet season attacks them hardest.

239 Exteriors applies a premium sealant to protect against weed growth between joints. Of sealers in general, ICPI writes: “Like stabilizers, sealers are also useful in stopping unwanted insects and weeds.” Of the stabilizers themselves: “Joint sand stabilizers help secure sand in the joint after it has been installed. Their primary function reduces the risk of removal of joint sand from flowing water, wind, aggressive cleaning, tire action and intrusion of organic matter, seeds and insects.” Stabilization is “generally optional and not required for many interlocking concrete pavements,” but ICPI recommends it on slopes over 7 percent and, in a line that could have been written for this coast: “Pavements that see regular, heavy rainfall can benefit from stabilization of the joint sand. Surfaces that experience concentrated water flow such as gutters receiving sheet flow from large areas or at the drip lines under the eaves of buildings will better resist erosion of joint sand if stabilized.”

Regular, heavy rainfall is the Naples normal. NOAA's 1991 to 2020 climate normals for Naples Municipal Airport put 32.67 of the year's 49.55 inches between June and September, with August alone at 8.89 inches. November through February each average under 1.7 inches. Every month's average temperature sits above 65 F, so warmth is there all year; the rain decides how much water there is.

One ICPI line worth keeping: stabilizers “do not add to the structural (load bearing) capacity of the pavement.” In ICPI's terms, a sealer and a stabilizer reduce what gets into the surface and can help hold sand in the joints. They do not fix a base that has settled.

Two water rules and two statutes can come up on a paver job in Naples: the county's standing water rule, the water district's shortage plan, and the association statutes on appearance and on condominium maintenance.

The county allows exterior washing on any day. Under Collier County's Ordinance 2015-27, the Phase I restrictions that govern irrigation, “the washing of exterior home surfaces and roofs, shall be allowed anytime with the use of Low Volume Pressure Cleaning Equipment, Low Volume Mobile Washing Equipment and/or water hose equipped with an automatic self-canceling or automatic shutoff nozzle,” and “in all cases, the water used must drain to a pervious surface or to a water recycling/reuse system.” The county's summary does not state the ordinance's reach inside a city, and Estero and Bonita Springs lie outside the county; the city or the water utility can say which rule covers a given address.

During a declared water shortage a second rulebook applies. The South Florida Water Management District's Chapter 40E-21 phase text restricts “outside pressure cleaning” to “only low volume pressure cleaning” in every phase, and the same subsection says “washing or cleaning streets, driveways, sidewalks, or other impervious areas with water shall be prohibited.” The district's order declaring a phase can modify those restrictions, so the ones in force are the order's. Which line governs a paver driveway during a declared phase is a question for the district and the water utility at the time, and the district posts the current status on its landscape irrigation page.

For appearance, the association's declaration is the document that counts. Florida Statutes 720.3035(1)(a) limits an association's power to “enforce standards for the external appearance of any structure or improvement” to what is “specifically stated or reasonably inferred” in the declaration or its authorized guidelines, applied “reasonably and equitably” to all parcel owners. ICPI writes that most sealers darken the paver surface, and a film-forming sealer adds gloss, which is worth a look at the standards before the sheen is chosen. In a condominium, Florida Statutes 718.113(1) reads: “Maintenance of the common elements is the responsibility of the association, except for any maintenance responsibility for limited common elements assigned to the unit owner by the declaration.” Which walkways and pool decks that covers, and who orders the work, is a question for the declaration.