Here in sunny South Florida, I’m partway through the tedious process of having a pool put in my back yard. It’s about time to pick the deck material. The main choices seem to be travertine or marble pavers.
Reading various blogs and such, I’ve learned that:
Travertine is great because it’s not as slippery as marble
Marble is great because it’s not as slippery as travertine
Both are fine as long as they are sand blasted
Both are fine as long as you use a non-slip sealant
You should never seal them, because that keeps the water from being absorbed, thus making them slippery
And a myriad of other contradictory advice.
I’m also interested in any differences with heat retention, since, again, this is South Florida and it gets fairly hot during the summer, which lasts roughly 15 months out of the year here.
Since this is the Dope, I assume we have members who are deck installers, geology experts, and someone who has run rigorous scientific experiments on the various options. Or, lacking that, other people who own pools.
I don’t think my pool company has limestone on their list, but I do have the option of sourcing the stone myself and having them install it. Although there would have to be a real benefit for me to add that effort to the project.
From a geology perspective - travertine will tend to be much more porous than marble, and have a better texture for grip as well. The porosity/lower density also helps with insulation, so it should not get as hot as marble, but colour is going to a bit of a factor there really.
Surface finish is very much personal preference, but I’d go with no sealant, myself. Rocks are fine as-is, why ruin them with chemicals? Unless your water is so acidic it’d eat either of these rock types away, they should be fine as-is.
No. Limestone is any sedimentary rock made of mostly of calcium carbonate (calcite or aragonite)
Travertine is one kind of limestone. Others include chalk, oolite, coquina, calcerous mudstone… there are lots of different kinds of limestone, but they are all sedimentary rocks i.e. they are deposited and turned into rock as limestone, and not significantly altered after that.
Marble is a metamorphic rock. It’s what happens when limestone or similar rock is subjected to heat and pressure and altered (mostly, the small crystals in the grains of sedimentary carbonite recrystallize, fuse and interlock into a mass of (usually) much larger crystals, usually losing all sedimentary structure). Any kind of limestone can become marble.
That was going to be my comment. Color makes a HUGE difference in how hot something sitting in the sun will get.
Also, i don’t know a ton of geology, but i would expect marble to be more slippery than limestone. It’s less porous. At least, all the limestone I’ve seen that i knew was limestone has been a lot more porous than any marble I’m familiar with.
I see Wikipedia says:
Fresh travertines vary widely in their porosity, from about 10% to 70%. Ancient ones may have porosities as low as 2% due to crystallization of secondary calcite in the original pore spaces, while some of the fresh aragonite travertine at Mammoth Hot Springs has a porosity greater than 80%. A porosity of about 50% is typical for cold spring travertine while hot spring travertines have a mean porosity of about 26%. Speleothems have low porosities of less than 15%.[15]
So i guess it varies quite a lot.
My other advice is to touch the stones you are considering before making a choice. I was redoing a staircase and walkway, and my choices were bluestone and granite. The contractor recommended granite, and i was quite dubious until he brought by a sample. I was mostly worried it would be slippery, but this granite has a rough enough surface that it’s good underfoot.
Any unsealed stone is likely to stain over time. I already have some leaf stains in my new granite walkway. I consider this a feature. Over time it will look more “natural” and less “shiny new”, and it will feel like it fits with the environment. I’d personally far prefer a nice natural patina’d stone than a chore to keep clean and resealed over time. But that’s an esthetic decision only you can make for your home.
Fwiw, I’m intrigued that your options are travertine and marble. Neither is used much outdoors and underfoot here in the northeast.
How about medium/large format porcelain? The patterns really really look like real stone now, and it will be way more stain resistant. Unsealed marble or travertine and red wine spills are no bueno. A non-slip sealant would be a must for the natural stones.
I’m leaning towards a grey/ivory/something shade, which should be a nice contrast with the pool and the house.
The “more porous → less slippery” makes sense to me. It sounds like travertine, which is pretty popular down here, may be the right answer.
It just occurred to me that the samples at the installer’s place are right next to an indoor pool. Next time I’m there, I should be able to at least splash some water on some samples and feel them.
