How to restore weathered pavers
Natural stone paving is touted for its longevity. With proper maintenance, an installation can last well over a hundred years. Over this time, the stone will be subject to weathering due to several factors, which could change the look of the pavers. The rate of weathering will be different depending on the area of the home that the pavers are installed. This is attributed to two main factors; exposure and frequency of use.
Areas that are exposed to the elements, such as driveways, walkways, and pool areas, are more prone to wear than patios. This is because they are usually pelted by the elements, in particular, rain, sleet, snow, frost, wind, and sunlight. Wind causes erosion of the stone over time, as different fine particles of dust and sand are scraped against the pavers. Rainwater pummels the pavers and too much of t can cause water damage. Snow and frost can cause cracking in the grouting, and in some cases, the pavers themselves. Sunlight causes color changes in natural stone pavers. Driveways and walkways are places that will experience a lot of traffic, from people, bikes, cars, and even pets. This causes the pavers to wear from friction and weight. Car tires and feet are particularly responsible for this and can result in various scratches and nicks. Over time, this accumulates to noticeable wear.
Other common agents that cause wear in natural stone pavers are acidic liquids and the stone’s natural processes. Acidic liquids cause something called etching, which is when the acid eats into the unprotected areas of the stone, changing both the texture and finish. Some stones such as marble and limestone are more susceptible to etching while others like granite are more resistant.
The most common type of natural oxidation is efflorescence. This happens when water carries mineral salts from the ground, rising through the stone and finally evaporating. This leaves a powdery substance on the pavers, which is mostly white. Over time, and with enough repetition, the effects of efflorescence can be seen on the pavers.
How do you deal with weathering on pavers?
Knowing what type of weathering is half the battle. The next step is looking at the various ways you can deal with it. It is important to note that there is no one-size-fits-all fix that takes care of everything, and each restoration job is unique to the type of weathering. Here are some of the more common fixes:
A dash of acid
One the very rare occasions where acid and natural stone avers interact is during restoration. Weathered stone can be treated with vinegar (contains acetic acid), a mild acidic cleaner (store-bought), or muriatic acid, to remove various substances. The acidic materials are mixed with water to make sure the acidic properties are only strong enough to act on the mineral deposits while remaining mild enough not to affect the pavers. This is the best way to deal with efflorescence.
Vinegar is the entry-level solution. It is applied to the surface of the stone and allowed to sit for several minutes. The acetic acid in the vinegar eats away at the mineral deposits, after which you can scrub with soap and water. If vinegar does not work, the mild store-bought stone cleaner. You should, however, be careful not to damage any of the adjacent grass and natural vegetation when working with store-bought cleaners.
Muriatic acid is another excellent option. This can be found in most hardware stores or home improvement establishments. This is the nuclear option when dealing with difficult mineral build up in your natural stone, and is perfect for dealing with deposits of calcium and salt. When working with muriatic acid, be sure to keep it away from cement. While it will not damage most natural stone, this acid has a voracious appetite for cement and will eat through grouting, and even concrete paving.
Test the water pressure
Another great way of dealing with certain types of weathering such as material build-up is simply cleaning the pavers. This is best done using a power washer because you need the extra power to push out the dirt and grime, exposing the natural stone underneath. This is usually the best way to remove material from the grouting, since acidic cleaners may damage the cement.
Buff and shine
One of the most common methods to deal with weathering on natural stone is buffing. This is done to deal with efflorescence, water damage, and even etching. The additional benefit of buffing is that it removes water spots as well, and is one of the first steps when preparing the pavers for polishing and sealing.
Buffing is best done using 0000 steel wool, to make sure you do not damage the paver. The movement should be along the grain. This makes the process easier to complete while ensuring that the natural stone wears evenly. Buffing can only be done to handle small nicks, tiny etches, and smaller mineral deposits. Deeper scratches will need to be repaired and polished by a paving professional.
What else should you know?
When restoring natural stone pavers, there are three things you should ensure. The first thing is to always use the correct method of restoration for the stone. Any sort of limestone-based paver should be kept away from muriatic acid for instance. Secondly, when dealing with any sort of DIY exercise, make sure that you are dressed for the occasion. Protective gloves, eyewear, boots, and a mask are a must-have. These will reduce the chances of injury on your soft parts (eyes, nose, face, and hands), from injury.
Finally, when in doubt, call a professional. As much as you enjoy doing certain things yourself, there comes a time when you have to seek the help of a qualified professional. This could be because of the complexity and size of the undertaking, or simply since its football season. A professional will also be able to identify and safely replace any cracked or broken pavers as well.