Marble Pool Coping: Top 5 Reasons For NOT Using It!

Is Marble Pool Coping Good?

Marble is the epitome of luxury and elegance in home décor and construction. But is marble pool coping a good idea? The answer is NO!

Marble pool coping is not a good choice because marble:

1. is porous, absorbs water and is prone to staining and discoloration. 
2. is rich in calcite which erodes rapidly when exposed to chlorine rich pool water.
3. is slippery, especially when smooth and wet.
4. gets pretty hot under the sun and is not comfortable for bare feet.
5. is relatively soft and is susceptible to scratching, cracking and chipping.

While marble is an elegant and sophisticated option for home décor, it is not the best choice for pool coping. Pool coping needs to serve many important functions, other than just looking pretty. Marble falls short on functional requirements of a pool coping.

There are several better alternatives such as travertine, slate or porcelain. 

What is Marble Pool Coping?

Pool coping is the decorative edge that surrounds the perimeter of your swimming pool. It provides a visual transition from the pool deck to the pool itself. Pool coping in a contrasting color, pattern or material can help define the pool and give it a unique character.

The pool coping is, however, a lot more than a visual border around the pool edge.

In fact the pool coping is an essential part of pool and deck construction and serves several very important functions such as:

• Protecting the pool wall and foundation from water ingress
• Keeping the deck dirt & debris from getting into the pool
• Providing a ledge for swimmers to hold onto and pull themselves out
• Adds to the aesthetic appeal of the pool and deck

When it comes to natural stones there are at least 10 great options for creating stunning pool decks. Marble is one of them.

Marble is a metamorphic rock, similar to slate. Unlike slate, marble is formed when limestone is subjected to intense heat and pressure in the earth’s crust. 

Marble tends to be lighter in color as its origin is limestone, which is rich in calcite. Marble is prized for its exquisite beauty, translucency, crystalline structure, distinctive veins and swirling patterns.

Marble pavers can be used for pool decks but it is not the best choice as it is relatively soft and porous. It is not very weather resistant and gets tarnished even by mild acids. Maintaining marble in outdoor locations can be quite challenging. 

For the same reasons, marble is not a great choice for pool coping.

What Are the Disadvantages of Marble Pool Coping?

Marble is not the right choice for pool coping as it has several disadvantages. The top 5 reasons for not using marble for pool coping are:

1. Stains & Discolors Easily: 

Marble looks fantastic, till you drop some BBQ sauce or spill some red wine on it. Marble is very porous. So liquids can penetrate deep into the marble pool coping.

Even if you were to enforce a “no eating & no drinking on the pool edge” policy, the marble pool coping could still stain from the tannins leaching out of dead leaves, twigs, insects, etc. You may even get stains from rust or mud.

2. Has Poor Chemical Resistance: 

Marble is crystalline in structure and calcite (calcium carbonate) is the main constituent. Chlorine used to sanitize your pool does it by forming a weak hypochlorous acid. 

Pool water permeates into highly porous marble coping and reacts with the calcite. Constant exposure to pool water will ultimately result in degradation of the marble pool coping.

The only way to protect marble pool coping is to seal it at least once a year.

I recommend Miracle Sealants 511QT6 511 Impregnator Sealer. It is very effective at protecting against water, stains & slippage. Another great option is to refresh your aged marble pool deck and coping with a coat or two of Black Diamond Color Enhancer Sealer.

3. Marble is Slippery: 

Smooth polished marble is fantastic as a countertop or backsplash. It is great to touch as your fingers glide effortlessly over the glossy surface. However, this is a recipe for disaster for a marble pool coping!

Of course, pool coping will get wet. Of course kids will run on pool coping. The last thing you want is a pool coping that is smooth and slippery, especially when wet. This is certainly a worrisome safety hazard for families with young children and elderly parents.

Best to avoid marble pool coping. If you must, use textured marble such as sandblasted or tumbled finishes. And make sure to incorporate an anti-skid additive in the topical sealer, such as H&C SharkGrip.

4. Gets Pretty Hot Under the Sun:

Polished marble tiles are cool to the feet, indoors but can get pretty hot when exposed to the midday summer sun. This has to do with the Specific Heat Capacity, which is an intrinsic property of natural stones and other building materials.

Data Source: Engineering Tool Box

Based on the above, marble would get hotter than travertine or limestone but not as hot as granite or concrete.

5. Will Scratch and Crack Easily:

The softness and hardness of natural stones is measured on the Mohs scale of hardness. Mohs scale ranks minerals on a scale of 1 to 10 where 1 (Talc) is the softest and 10 (Diamond) is the hardest.

Natural Stone	Mohs Hardness
Slate	2.5 – 4
Marble	3
Limestone	3 – 4
Travertine	4 – 5
Flagstone / Bluestone	6
Sandstone / Granite	6 – 7

The above table compares some of the natural stones commonly used as pavers for decks and patios. As you can see marble is pretty low on the scale. This is the reason marble gets scratched very easily.

Marble is composed of an interlocking mosaic of carbonate crystals. As a result marble can chip quite easily along the crystalline fault lines. A marble tile will crack or even break if it gets hit by a heavy object.

Bottom Line

The bottom line is that though marble is exquisitely beautiful it is best to use it indoors and in areas which will not get wet or be exposed to even mild acids or chemicals. There are 5 compelling reasons for not using marble pool coping.

Thank you very much for reading the post. I do hope you found it informative and helpful.