By Liam Ouanounou
More of the renovations coming through our showroom on Myrtle Avenue this year involve a roof or a backyard, not just a kitchen or bath. Homeowners who spent a few summers eating dinner on a plywood-decked rooftop or a cracked concrete patio are ready to treat that square footage like an actual room — one that survives a Brooklyn winter instead of getting power-washed and forgotten every October. The material driving most of that shift is outdoor porcelain paving, and understanding how it differs from indoor tile is the difference between a rooftop that lasts and one that needs re-doing in three years.
Why porcelain pavers, specifically
Natural stone and old-style concrete pavers have long dominated NYC outdoor spaces, but 2cm-thick porcelain pavers — roughly twice the thickness of standard interior porcelain tile — have become the default recommendation we give contractors and homeowners planning a rooftop or patio. The thicker body resists cracking under point loads (a planter, a grill, a stiletto heel) better than natural stone of comparable size, and unlike stone, porcelain doesn't need periodic sealing to resist staining from bird droppings, leaf tannins, or de-icing salt — a real maintenance difference on a roof deck eight flights up that nobody wants to climb to reseal every spring. Much of the porcelain we bring in is manufactured through-body, as we've written about in our large-format porcelain piece, so a chip from a dropped tool doesn't reveal a different color underneath the way an older glazed surface would.
The two numbers that actually matter outdoors
Indoors, PEI rating is the number that decides whether a tile holds up to foot traffic. Outdoors, two other specs matter more: slip resistance and freeze-thaw performance.
Slip resistance for wet, sloped, or pool-adjacent surfaces is measured under the DCOF (dynamic coefficient of friction) method in ANSI A326.3, and most outdoor porcelain pavers we sell are formulated with a textured or structured surface to clear the wet-area threshold that a smooth interior tile can't meet. Freeze-thaw resistance is the second gate: a tile has to be rated for repeated freezing while saturated with water, since a rooftop or patio in this climate goes through dozens of freeze-thaw cycles every winter. Porcelain's very low water absorption — typically under 0.5%, versus several times that for many natural stones — is what lets it survive that cycle without the surface spalling or cracking, which is why we steer clients away from interior-rated tile no matter how good it looks in a showroom sample.
Rooftops raise the stakes further
A backyard patio sits on grade; a rooftop sits on a waterproofed membrane that has to keep working for decades, which changes the installation approach entirely. Rooftop porcelain is typically set on a raised pedestal system rather than a mortar bed — the pavers rest on adjustable plastic pedestals over the roof membrane, creating a drainage gap underneath so water sheets off to the roof drains instead of pooling under the tile. It also means the deck can be lifted for membrane inspection or repair without demolishing the finished surface, which matters on a building where the roof deck sits directly over occupied space below. 20 Pine St, a mixed-use Manhattan building we supplied tile for, is a good illustration of why one building can need two completely different specs: the open rooftop terrace takes everything a New York winter does to it, while the pool and spa level sits indoors and never sees a freeze-thaw cycle at all. Rooms that photograph similarly can sit at opposite ends of the durability conversation, which is why "where is it, and what's underneath it" is the first question we ask.
Furniture, shade, and the parts that aren't tile
The tile is the foundation, but the reason a rooftop or patio actually gets used year-round usually comes down to what surrounds it: a pergola or retractable shade structure, weather-rated outdoor furniture, and often a fire feature or heater that extends the season into late fall. New York City's Department of Buildings guidance on occupiable rooftops and terraces (Buildings Bulletin 2018-002, PDF) also affects what's structurally and legally permitted up there, particularly for anything requiring guardrail height changes or added dead load like a raised paver system, planters, or a fireplace — worth a conversation with your architect or contractor before finalizing a layout, since it can affect which paver thickness and pedestal height make sense.
What to bring to a consultation
If you're planning a rooftop or patio project, the most useful things to bring us are the square footage, whether the surface sits over occupied space or on grade, and any existing waterproofing or drainage plan your contractor has already specified. That combination lets us match you to the right paver thickness, finish, and slip rating rather than defaulting to whatever looks best under showroom lighting. Our 4EVER and Cobb collections are both worth a look for outdoor work, and we can order samples of anything you'd like to see in person. If you're mid-planning on a rooftop, patio, or backyard project anywhere in the Tri-State area, get in touch and we'll help you think through the material before the contractor breaks ground.