Limestone
Limestone is a beautiful substrate to use on a project, the problem is that limestone lives in the ground where it is protected from the elements, never seen the sun, rain or polluted air. Once exposed, water, wind and organic growth start to wear the stone away. By eliminating the organic growth with chemistry to ensure regrowth has to start from square one, followed by a water treatment to keep water from lingering in the stone, we can make sure the limestone stays protected from water and stay looking clean for much longer when water can't linger in the stone as long as it usually does without a protective treatment.
Why is organic growth bad?
Limestone, a Mineral Sponge
Limestone is a very porous stone, which gives it the characteristics of a sponge. It likes to absorb water and anything else the water is carrying. Landscaping can be a great source of organic particulate matter that likes to make it way into the surface of the limestone and begin its growing process. At this point, it begins to grow as long as a couple conditions are met, the conditions being that there is moisture (a source of water), low light (usually north facing areas) and low wind (not the biggest factor). If a lot of organic growth is occurring, that means there is a source of water and water tends to cause harm to limestone.
Water, Limestone's enemy
Water is the number one cause of problems regarding masonry, especially limestone. Water can erode and break apart the stone over time when left untreated and not addressing the issue of where and why the water is making its way to the stone. Sometimes just moving the sprinkler heads can help prevent water damage followed with a protective treatment to help with any water overspray being pulled by the wind. The treatment helps keep water out while also letting whatever water is still there dry faster. This helps slow down organic growth by limiting its source of water.
Take it back to square one
Using the correct chemistry for the job
Organic growth isn't the only problem caused by water. Water can cause rust staining, stone spalling, lime and calcium growth and much more, what we do requires extensive knowledge through previous works with Limestone and using the correct chemistry to solve the issue. we don't just wash off the organic, we kill the organic so it requires more work for organic to start growing again. We make sure to use the correct cleaner so another problem isn't created, we treat stone with the care it deserves. Every stain is different, therefore every cleaner is different. What removes rust won't remove paint, what removes paint won't remove calcium. Every job is a puzzle that we love to solve.
Powerwashing?
Never never never powerwash. We would never suggest power washing your stone, we use a low pressure and high flow washer that won't harm the stone. Other washers have too much pressure and will cause more harm than good. It can etch the stone, create more voids for organic growth and drive water deeper into the stone. Trying to fix washer damage can sometimes be impossible, it's best to see what needs to be addressed and then set a plan of action that would start with the least invasive method available for the issue.