5 Top Tier Tips For Winterizing Limestone and Flagstone Patios
Updated: Dec 9, 2022
These absolutely essential tips will ensure your stone patio will last for generations to come.
With over 50 years of experience under our belts, we know a thing or two when it comes to winterizing stone patios. NOTHING is more detrimental to the lifespan of your natural stone than winter's brutal freeze-thaw cycle.
When we think of a stone, we typically associate it with being strong, tough, and practically indestructible.
However, flagstone and limestone are porous - meaning they have tiny holes that liquid and air can pass through.
As snow melts, extremely small amounts of water fill the pores of the stone. When the temperature drops below freezing, these small pockets of water solidify and expand into ice - causing the pores to expand and macro-cracks to form.
As this occurs, those tiny holes grow larger and larger with every cycle. It may not sound alarming at first, but, over the course of decades, this process will destroy the stone from the inside out - leading to flaking, or spalling, and potentially... a need for replacement.
Below, we share some of the most invaluable tips we've learned over the years that will ensure your patio lasts for generations to come.
Tip #1 - Seal Your Stone
Contrary to popular belief, it is IMPERATIVE that you have your stone sealed. Not even a question - it is CRUCIAL for a long-lasting patio.
Now there are many different types of sealer out there. "How do I know which sealer is the right one?" Due to these particular stones being porous, we are going to need a penetrating sealer.
This particular type of sealer is made from siliconates, fluoro-polymers, and siloxanes - which imbed themselves deep into the pores of the stones to actively repel water while also preventing staining to the stones' natural rock face.
Most penetrating sealers require the use of special cleaners prior to sealing. These cleaners both clean the stone and imbed additional water repellent which binds with the sealer.
This helps create a longer-lasting bond than topical sealers and gives added protection with the ability to repel more water.
We highly recommend deep cleaning your patio before using any special cleaners to ensure there is no debris that may prevent the repellent from binding.
Sealing your limestone or flagstone patio tremendously helps prevent any damage from occurring during freeze-thaw cycles and ensures your stone will retain its natural color for many years to come.
*The freeze/thaw cycle takes decades before you notice damage to your stone. In terms of its potential lifetime, not having your patio sealed is detrimental.*
Tip #2 - Deep Clean Your Patio
Regardless of whether you have sealed your stone or not, the next tip to winterizing your patio is to give it a deep clean. When we say a deep clean - we mean a DEEP CLEAN.
Before the snow starts falling, it is key to remove fallen leaves, sticks, and other natural debris from your patio as they will break down over time.
Debris, such as leaves, can block the sun and wind from evaporating hidden pools of water.
Even if your patio is sealed properly, you don't want moisture and water to pool around in one area for extended periods of time, especially.
Allowing water to pool for extended periods of time is not good for the health of your stone. The sticks, leaves and other natural debris break mixed with the water breakdown into organic matter.
This causes organic matter to develop which can potentially stain and damage your gorgeous limestone or flagstone patio.
An additional benefit to a clean patio surface is having open air and wind to keep moisture from pooling in the divots of the rocks' natural face.
Ideally, you should be cleaning your patio with a leaf blower, power washer, or broom weekly throughout the fall.
Another key when it comes to deep cleaning is to remove any weeds or plant life on your patio.
If they aren't removed, there is a possibility the plants will shift during the spring when they sprout again; potentially causing damage to your stones. *ouch*
Tip #3 - Store All Unnecessary Furniture
Another way to help maintain the integrity of your patio is to winterize your patio furniture.
Winters aren't just harsh on us - our furnishings can also take quite a beating. Most patio furniture is susceptible to winter's cold conditions.
Any type of material including wicker, steel, iron, plastic, glass, unwinterized wood, and stone runs the risk of warping, cracking, and or breaking if left outside, unprotected all winter.
The only materials that do not need winterizing are those made of aluminum and sealed wood.
Fortunately, there are many products and solutions to ensure our furnishings last.
One solution is to store your furniture in a dry, covered location such as a garage or shed. This ensures your furnishings are not only moisture-free, but won't be enduring the additional weight snow and ice can bring.
If those are not available to you, there is an abundance of tops and covers available for tables and chairs to keep them protected. We recommend storing the covered furniture beneath a deck or close to your home if possible.
We strongly suggest that you clean everything deeply before storing it. Doing so will help prevent the growth of mildew or mold and extend the lifetime of your furniture.
If you're planning on enjoying a few warm, cozy fires this winter, we recommend only leaving out winterized furniture that will be USED! This helps your patio by displacing the constant weight that your furniture adds and makes the next step all that much easier.
Tip #4 - Remove Snow As Often As Possible
As we went over before, winter's freeze-thaw cycle is the nemesis of limestone and flagstone patios. If you allow snow to accumulate, it will eventually melt and soak into the stone.
As temperatures plummet below freezing again, the water turns to ice and expands within the pores of the stone. We already know - this means trouble...
One very important tip for maintaining the integrity of your patio is to remove snow as frequently as possible.
I know, I know, nobody likes to shovel snow - especially in frigid conditions.
However, it is strongly recommended that you remove snow as often as possible to help prevent any damage from occurring.
More often than not, people use metal or metal-tipped shovels during the winter to help with breaking up any ice that may develop. This is a BIG no-no for your patio.
Using a metal or metal-tipped shovel runs the risk of permanently scratching, chipping, or breaking portions of your stone patio. It is HIGHLY RECOMMENDED that you ONLY use plastic shovels for clearing the snow.
If you are fortunate enough to have already sealed your patio, you have peace of mind knowing there is added protection. We still encourage you to remove snow whenever you can.
Tip #5 - Melt Ice With CMA
Our final tip is a BOMBSHELL. This tip is just as important as having your patio sealed. Let us explain.
What's the first thing you think of when it comes to removing ice? More likely than not, it's "Throw some salt on it."
While this is correct, it is PARAMOUNT that you use the correct form of salt.
Common road salt, sodium chloride, is the most common de-icer in the world. This is because it is abundant, cheap to produce, and doesn't have any negative effects on asphalt - which is the most de-iced surface in the world.
But it does have negative effects on limestone and flagstone. Sodium chloride corrodes the stone from the inside, causing it to discolor, chip, crack, or crumble.
DO NOT EVER USE ROAD SALT ON FLAGSTONE, LIMESTONE, CONCRETE, OR ANY OTHER TYPE OF POROUS STONE.
De-icing salts work by lowering the freezing point of water. When the salts are dissolved into the snow and ice, the solution becomes saturated and will not freeze until temperatures drop below a certain threshold.
In the case of common road salt, a mere 20 °F.
This is less than adequate. More often than not, we have winter days that dip below the 20-degree threshold, and when this occurs, the freeze-thaw cycle becomes a threat once again.
This means we need to push our freezing threshold lower - with something that is safe for porous stone.
Enter CMA, or calcium magnesium acetate. CMA is an alternative to road salt and is made from a combination of limestone and vinegar. Per Wikipedia:
"It is approximately as corrosive as normal tap water, and in varying concentrations can be effective in stopping road ice from forming down to around −17.5 °F (−27.5 °C)."
CMA is the ideal solution to keeping ice off of your limestone and flagstone patios. Its ability to lower the freezing threshold of water to below zero and the fact that its non-corrosive make it the perfect choice.
There isn't a product more suited for winterizing limestone and flagstone patios than calcium magnesium acetate.
Enjoy Winter Without Worry
Congratulations! You now know the pro tips when it comes to winterizing your stone patio. You can rest assured knowing your investment is properly taken care of.
If you have any additional questions that weren't answered here, don't hesitate to ask them in the comments below!
For more info, check out our website and stay tuned for more posts!