Expert Answers
QUESTION
Granite Exterior Use: We are planning on using a black & tan granite on an outside installation of an outdoor kitchen in southern Mississippi. The granite will be in an area that is direct/indirect sun nearly during peak sun times. How can we expect this to affect the granite surface? We realize the surface will get hot but will the weather & temp damage the granite over a reasonable amount of time (say 5 to 10 years).ANSWER
ANSWER - Granite is normally one of most durable natural stone and normally very resistant to climatic conditions. Although today stone comes from all over the world in various degrees of quality and is processed differently.
Dark stone does get very hot, so you need adequate movement joints throughout. Stone must be protected from underlying moisture to minimize potential staining and spalling. Much of the stone today is being treated with resins during the manufacturing process to help stone be more durable through the manufacturing process. There is no standard for these resins so some have been known to be sensitive to some of the climatic elements.
Your particular stone would have to be researched and evaluated to determine if there is any known history of problems with that type, plus it would have to be tested to determine how its performance characteristics compare to industry standards.
It is a natural stone so there are no performance guarantees, but you can evaluate it to make a better decision.
We do evaluate ceramic tile and stone for product suitability relative to the application for an hourly fee plus the cost of any testing.
6 thoughts on “Will the weather and temp damage granite on outside installation?”
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Hello,
I was wondering what is the best adhesive/glue to use when adhering 3cm granite to a block wall outside.
As long as the back of the granite is clean and the concrete block is clean and porous you can use either an ANSI A118.4 modified thin-set mortar or a better performing ANSI A118.15 thin-set mortar.
I am trying to select granite for an outdoor table top and granite top that is totally exposed to a phoenix az sun. I have read that various types of granite have more or less resin than others which may affect discoloration and quality of service. I have no idea how to determine resin content or if it is even important. Would appreciate some help.
Many granite slabs of stone are sealed with a penetrating resin at the production plants in order to enhance the color of the stone and to stabilize the stone. There isn’t any standards on what type of resin to use or how to use it for applying to the stone.
I’m not sure if whether the stone is treated with a resin will make it more resistant to the exterior heat or not. It would be best to have some sort of cover or canopy over the stone so that it isn’t subjected to too much heat.
Hi,
we had a new outdoor granite counter (Fantasy Brown) installed last fall. It was sealed after completion of project. They told us to reseal every 6 months. We are just now about to seal it but have noted a color change (darkening ) of some of the stone and we don’t like the color. Can we get the original color back by some sort of treatment.? We did hose it down a few times with our well water and wonder if this contributed to the color darkening ? It’s located in partial shaded area with oaks trees nearby. we tried to use the granite cleaner but didn’t take away the color change. shall we seal it now anyways or try to change the color back first? I wonder if there might be iron in the stone itself that is starting to oxidize? appreciate your thoughts
A true granite is very dense and impervious as per ASTM C615 its absorption cannot be greater than 0.4% to be considered a true granite.
Sealers only provide temporary protection and with a granite it can’t absorb much of the sealer. You can’t say with certainty how long a sealer will last as it depends on the climatic conditions and wear that it is subjected to. The rule-of-thumb is if you put a dimes size drop of water on the granite and it either readily absorbs the water or if after you wipe it off it left a dark damp spot, then it means it needs to be resealed.
It is hard to say what could cause your granite to darken in spots, but it may more likely be from some greasy substance or staining liquid like wine that has caused it. Most stones do have iron sulfide within it to some degree that under very wet conditions can develop rust spots. That isn’t common with granites. It is possible that your stone isn’t a true granite as there are different sub-categories of stones that look similar but have weaker physical properties. You don’t want to reseal until the granite is in an acceptable condition or you will trap the stain in the stone.
Depending on the type of surface the granite has it can cause the granite to be more absorbing and more prone to picking up dirt and being more difficult to clean. Such as flamed or leather or bush hammer surface compared to a polished or hone surface.
The beauty of natural stone is that in theory, you can refinish the granite with a light grinding and repolishing or rehoning the surface and it will look like new. You need to hire a professional and experienced Stone Restoration company who specializes in restoring natural stone.