Last Updated on October 20, 2026 by Umar Farooq
Bluestone pavers are cut slabs of a dense blue-gray sandstone quarried mostly in Pennsylvania and New York. They come in two main surfaces, thermal (flame-textured and flat) and natural cleft (split along the rock and uneven), and they are the default hard-wearing stone for cold-climate patios, walks and steps. Expect low absorption, long life and a surface that gets properly hot in full summer sun. Buy it for steps, walkways and shaded patios, and think twice for a south-facing pool deck.
I went through three bluestone guides, one from a design magazine (Houzz), one from a stone supplier (Stone Center) and one on cost (Bob Vila), to find where they agree and where one of them is selling something. If you are still weighing stones, our natural stone pavers guide compares bluestone with granite, travertine, slate and limestone.
What bluestone is, and what the name hides
Despite the name, bluestone is not one fixed rock. In the US it is a sandstone quarried on the East Coast, mostly blue to blue-gray, and Houzz describes Pennsylvania bluestone as the classic, with the stone coming from Pennsylvania and New York and other sources giving blue-tan and blue-gray tones. The Stone Center guide calls it a dense sandstone or siltstone and lists colours from blue-gray to charcoal, with rust and green undertones.
The name matters for one practical reason: no standard I opened defines "bluestone." Some sellers label any grey sandstone as bluestone. So ask where the stone was quarried and ask for its absorption figure. Stone Center puts typical bluestone at 1 to 5 percent water absorption, which is a useful ballpark but a supplier's figure, not a guarantee. For comparison, the concrete pavers in the CMHA guide specification average 5 percent absorption at 8,000 psi.
Bluestone is geologically a close cousin of the stones in our sandstone pavers guide, and the same rule applies: the test sheet tells you more than the colour name.
Thermal or natural cleft: the surface you will walk on
Bluestone is sold in two finishes, and the choice shapes how the patio looks and how flat it lies.
| Finish | How it is made | What you get |
|---|---|---|
| Natural cleft | Split along the stone's natural layers | Textured, uneven face. The most slip-resistant option, with some variation in thickness |
| Thermal | The surface is heat-treated | A more consistent, flatter face. Smoother, but still grippy |
Both bluestone pavers finishes work as walking surfaces. Houzz and Stone Center agree on that, and agree natural cleft is the grippiest.
My practical rule is this. Choose thermal for dining areas, because chair legs and table legs behave on a flat face. Choose natural cleft for steps, shaded damp paths and anywhere traction beats neatness. If you are unsure, order one sample of each and run a chair across them.
Cut sizes, flagging and how a pallet really lays out
Bluestone comes in two shapes:
- Cut pavers. Squares and rectangles. Houzz lists sizes from 4 x 6 inches up to 36 x 36 inches, sold by the pallet or the ton.
- Irregular flagging. Natural-edged pieces specified by a width range, laid organically with wider joints. Our flagstones guide covers that format.
Ashlar, a mix of sizes in a staggered pattern, is the most common layout for cut bluestone, and running bond also works. The drawing above shows the usual three-size mix. Two ordering tips:
- Order by the pallet pattern. Many suppliers sell a "pattern pack" with the size mix already worked out, so the proportions come out right.
- Buy extra. Allow for cuts and for stones you reject for colour or chips, and keep a few spares for repairs, because a second order years later rarely matches.
Houzz also notes that bluestone is thick and heavy, with slightly imperfect rectangular or square shapes. Weight matters when you carry it. Our paver weight per pallet matters for planning deliveries.
Heat: the catch with a dark stone
Dark stone absorbs sunshine. Stone Center says plainly that bluestone retains heat, so pool decks and south-facing patios in full sun may get too hot in peak summer. Houzz does not mention heat at all, which tells you something about magazine guides.
What helps:
- Choose lighter blue-gray or silver tones over charcoal.
- Give it shade. A pergola, an umbrella or a tree turns a hot patio into a usable one.
- Use natural cleft only after checking it with bare feet. A textured face is not a cooler one.
- Consider limestone or a lighter stone for a poolside. Our pavers that don't get hot guide compares the options.
None of the sources gives a surface temperature for bluestone, so I will not invent one. Sit a hand on a sample in the afternoon sun before you commit to a pool deck.
Why bluestone is the northern default
Cold climate is where bluestone earns its reputation. Water that gets into stone freezes and expands, and porous stone suffers most. Stone Center rates bluestone's freeze-thaw performance as excellent because of that low porosity, and says it can last 40 to 60 years or more. It also warns that lower-grade stone with visible layering can flake if water freezes between the layers.
That warning is the useful part. A dense, tight-grained bluestone is a very safe choice in a hard winter, while a layered, soft one is a gamble. Ask for the stone's absorption and look at the edges of the sample for visible layering. If you are comparing with other options for freezing climates, our natural stone guide covers the split.
Stone Center also notes that new installs can show efflorescence, a white mineral film that is cosmetic and usually fades after the first season. Do not scrub it with acid on day one.
Laying bluestone on sand or on mortar
Both methods work, and the stone's thickness and your climate decide which.
Sand-set. Thicker cut pavers can go on a screeded sand bed over a compacted base, like any paver. ICPI Tech Spec 2 asks for at least 4 inches of compacted crushed stone under a patio or walkway on well-drained soil, 2 to 4 inches more where the ground is wet or freezes, and a nominal 1 inch of screeded, uncompacted bedding sand. CMHA's guide spec says to leave the sand undisturbed once it is screeded. Use ASTM C33 concrete sand. The base should be flat to within 3/8 inch over a 10 foot straightedge, and ICPI allows a maximum of 1/8 inch lippage between pavers on pedestrian routes.
Mortar-set. Thinner stone or a formal look calls for a full mortar bed over a concrete slab, with its own slope and control joints. Rigid and permanent, but more expensive and harder to repair.
My view on this one is simple. A thin base under premium bluestone just gives you very expensive wobble. The pavers are the finish. The base is the patio, so put the money and the effort into the 4 inches underneath. Our paver base guide covers depth and compaction.
Because the stone is dense, cutting is slow and dusty. Use a wet saw or a blade with water delivery. OSHA's rule for masonry saws is water on the blade, every time (29 CFR 1926.1153), and a respirator indoors.
Sealing bluestone, and when to leave it alone
Stone Center says to reseal every 3 to 5 years and to seal before first use. That is a sensible check date, not a schedule. Dense bluestone resists stains better than limestone or travertine, so some owners never seal. Seal if you want a richer colour, if you cook near the patio and grease will drip, or if the stone is lighter and more absorbent.
If you do seal:
- Let the stone and the joints dry fully first.
- Use a breathable, penetrating sealer for natural stone rather than a glossy film.
- Test a spare paver, because some sealers darken the stone.
- Reseal when water stops beading, not by the calendar.
Houzz suggests a gentle pressure wash every few years, and says pavers that settle unevenly on a sand bed can be lifted and reset.
What bluestone costs, and the cheaper look-alike
The cost figures from two sources are in the same range, which is rare. Bob Vila puts a bluestone patio at $18 to $30 per square foot installed. Stone Center says $8 to $18 for the material and $15 to $31 installed. Bob Vila also quotes labour at $50 to $80 per hour. Both are cost guides with their own context, so treat them as ranges and get local quotes, because region, finish and pattern move the price.
Here is the cheaper option first, as it should be. Bob Vila notes that Pavestone, a tumbled concrete paver that imitates bluestone, averages about $4 per square foot. For a back patio with no steps, a blue-gray concrete paver gets you most of the look for a fraction of the price. Real bluestone is worth the premium where it will take the most punishment for the longest time: steps, entry walks and the patio you plan to keep for decades.
Spend bluestone money where the wear is
Bluestone pavers are the safe bet for freezing winters, heavy foot traffic and steps, and the wrong bet for a sun-baked pool deck unless you choose a pale tone and add shade. Choose thermal for tables, natural cleft for grip, ask where the stone was quarried and what it absorbs, build a flat 4 inch base, and seal only when water stops beading. For everything else, a good concrete look-alike is nothing to be ashamed of. The stone has waited a few hundred million years to be a patio, so it can wait while you order a sample.
FAQ
What is the difference between thermal and natural cleft bluestone?
Natural cleft is split along the stone's layers, leaving a textured, uneven face with the best grip. Thermal is heat-treated to give a flatter, more consistent surface that is still grippy. Choose thermal for furniture and natural cleft for steps and damp areas.
Do bluestone pavers need to be sealed?
Not always. Bluestone is dense and resists stains better than limestone or travertine. Stone Center recommends resealing every 3 to 5 years, but the better rule is to reseal when water stops beading. Use a breathable sealer for natural stone.
Is bluestone good for a pool deck?
It can be slippery or hot. Natural cleft grips well wet, but dark bluestone retains heat, so pool decks in full sun may get too hot. A lighter blue-gray or silver tone, or a different stone such as limestone, is easier on bare feet.
Is bluestone good in cold climates?
Yes, it is one of the best choices. Its low absorption means little water to freeze in the stone. Avoid lower-grade stone with visible layering, which can flake if water freezes between the layers.
How much does a bluestone patio cost?
Bob Vila lists $18 to $30 per square foot installed. Stone Center gives $15 to $31 installed and $8 to $18 for material alone. Get local quotes for your finish, pattern and region.
Is bluestone a type of sandstone?
In the US, yes. Bluestone is a dense sandstone quarried mainly in Pennsylvania and New York, and the name is a trade term rather than a defined standard. Ask for the quarry source and absorption figures.
