Tiling Outside Spaces


Gray porcelain tile patio
These sandy-textured, high-density porcelain tiles are perfect for a slip-resistant, durable patio installation.

Freeze and Thaw, Contraction and Expansion, and the Wonder of Washington State Weather


Snow-covered spruce tree branch

Here in the Pacific Northwest, we have hot summers, cold winters, and a lot of snow, sleet, and rain in between. Any material you use in an outside space will be exposed to the elements and temperature changes; if your product is not suited for the weather or if it's installed improperly, your installation will fail. We've seen broken tiles, stained stone, peeling grout, and excessive water damage result from bad installation practices.

 

Fortunately, we're here to help you choose the right materials and utilize the proper techniques to create a durable outdoor installation.


Can I install in this weather? Temperatures & Install

Many installation materials such as grout, caulk, and thinset have a temperature range in which they can be installed. If its too cold or too hot, the products won't cure properly. For example, Laticrete 317, our recommended unmodified thinset for Schluter Ditra and Kerdi, can't be installed on surfaces colder than 40° F or warmer than 90° F. In instances of extreme summer heat or chilly winter nights, you may have to put your project on hold for a few months.

Freeze and Thaw

Broken boulder cracked due to freeze thaw
If this is what happens to a stone in nature, imagine what could happen to a too-porous tile in your back yard!

When a very porous tile is left outside in the rain, it will absorb the moisture, which will expand upon freezing, potentially causing the tile to crack.

 

The tile industry standard recommendation is no more than 5% porosity; under 3% is ideal. Certain natural stone and ceramic tiles are not suitable for outside installations due to their porosity. Meanwhile, there are numerous porcelain product lines specifically approved for exterior use.

 

Ask us about specific products you are interested in and we'll tell you how well it will hold up in your installation.

Contraction and Expansion

It's basic physics: matter expands when warm, and shrinks when cold. This is true of tile and stone.

 

Inside of a house, the temperature is fairly consistent, and as such contraction and expansion aren't major concerns for most tile installations. Outside, however, where your tile can experience temperatures from over 100º F to below freezing, you need wide enough grout joints with flexible enough grout to give your tiles some wiggle room. We recommend at least 1/8" grout joints and either urethane or single-component grout.

Expansion Joints

Schluter Dilex-BWS over Schluter Ditra
Schluter Dilex-BWS over Schluter Ditra

To help protect your tile from future damage, you'll need to include expansion joints into your installation. An expansion joint is needed at least every 10 linear feet, and an expansion joint at least 1/4" wide is needed around the perimeter of the installation if you're meeting to a solid surface or a wall.

 

We recommend using the flexible color-matched caulking designed to accompany your grout in the expansion joints, or an engineered expansion joint profile such as Schluter Dilex.

 

If you are tiling over a concrete slab, generally speaking you'll want to align the expansion joints between your tiles with the expansion joints in your concrete slab. Both sets of expansion joints are necessary to prevent damage to your installation.

Proper Slope and Drainage


Schluter Bara-RTK edge gutter system
Schluter Bara-RTK

Just like with your roof, you want tiled patios and decks to have enough slope to carry water off of and away from your house. The recommended slope is 1/4" of height difference for each linear foot.

 

We recommend one of Schluter's drainage and gutter systems for patios, balconies, or decks that are above an open area or living space.

 

Waterproofing


Schluter Ditra is installed under tiles on a patio
Schluter Ditra creates both a waterproof barrier and a solid underlayment for these patio tiles.

If your tile is going over some sort of wood product (on a deck or outside countertop, for example), or if there's potential for water to leak or drain into your house, you need to waterproof your installation.

 

With a concrete substrate, there is a chance that moisture can creep up through the concrete and create problems in your tile installation. Waterproofing is often recommended, but not always necessary.

 

There is a common misconception that an impervious tile and pore-free grout will act as a waterproof barrier when used together; but porcelain and grout are not intended to be waterproofing materials, and should never be relied upon as a moisture barrier.

 

We carry several different waterproofing products, but we recommend Schluter Ditra as a waterproofing underlayment that doubles as an anti-fracture membrane. Ditra will help prevent cracking tiles and act as a vapor barrier, stabilizing your installation.

 

Have a look at this example of a contractor fixing an improperly installed tile patio with proper slope, drainage, and Ditra as an underlayment and waterproofer.

Tiling over Concrete


Anti-Fracture Membrane

Schluter Ditra Uncoupling Membrane

If your concrete is relatively new (under 15 years old), you will need an anti-fracture membrane (such as Schluter Ditra) between your concrete and your tile. There is a chance that the concrete can settle and crack, the movement of which will transfer to your tiles and cause them to crack.

 

If your concrete is over 15 years old, it has had a chance to settle and an anti-fracture membrane is optional.

Waterproofing

Water can get through concrete. If you have a concrete slab close to your house, there is a chance that moisture will get into the structure of your home through the concrete and cause structural damage. 

 

Waterproofing your concrete before tiling will prevent moisture damage and make for a better installation. Some waterproofing methods (including Schluter Ditra and TEC HydraFlex) can double as an anti-fracture membrane for added stability.

Recommended Products for Outside Spaces


Porcelain Tiles Approved for External Use

Bakery Tiles in the color Rye are suitable for a patio installation
These tiles are approved for high commercial foot traffic and external use, an incredibly durable option for outside installations.

Porcelain is one of the strongest, most dense tile products available today. Several porcelain lines are designed specifically for Pacific Northwest weather: they are thick, almost completely pore-free, and extremely frost-resistant. These tiles are available in a wide variety of colors, shapes, sizes, and textures, and are ideal for outside use.

For Countertops

New Venetian Gold granite Fire Pit cover
Granite top fire pit

Solid surface granite countertops and low-porosity tiles work well in outside spaces.

 

Quartz countertops, despite their strength and durability, are not recommended for outside installation; the resins in quartz can yellow in sunlight and the manufacturer will often NOT warranty an outside installation.

A tiled countertop in an outdoors patio kitchen

You can also use porcelain or natural stone tiles rated for exterior use on outside countertops. These tiles are less expensive than solid surface countertops, and you can even install them yourself.

Natural Stone with Low Porosity and Specific Mineral Content

Black and Gold slate 12x24 tiles
Some stones may be perfect outside in a warm climate, but many will not withstand a Washington state winter.

Certain high-density limestone, quartzite, and other stone varieties have porosity below 3% and can withstand the freeze/thaw of a Pacific Northwest winter. 


Some stone tiles, including many slate colors, have iron and other minerals that will bleed when wet. In western Washington, this could mean rusty, stained stone 9 months out of the year! 


Check with your retailer to find out if your desired stone is suitable for an outside space.

100% Recycled Granite Pavers

Pavers by a swimming pool
Unpolished granite pavers provide excellent pool-side friction.

We have an exclusive line of reclaimed granite pavers perfect for outside spaces. These durable, colorful pavers are available both polished and unpolished in a wide range of sizes, shapes, patterns, and color blends.

 

Visit our Granite Paver page for more information.

Durable Grout (and Caulking!)

Porcelain tile patio with mosaic stripes
Exterior-grade porcelain set with a highly-durable grout

We do NOT recommend setting tiles without grout (difficult to clean, potential damage to the thinset or underlayment, unfinished look) or without space in between the tiles (potential for tiles to expand, buckle, and separate from their thinset).

 

We recommend at least an 1/8" grout joint to allow for contraction and expansion of your tile, and using a grout with some flexibility (such as Fusion Pro or urethane grout). These grouts are non-porous and extremely stain-resistant, never requiring sealer.

 

Tent your installation after grouting to protect it from rain and allow airflow; Fusion Pro and urethane grout needs 3 days to fully cure.

 

You'll also need caulking for your expansion joints. The caulking has more flex than the grout, but is designed to match your grout's color and texture. You can also use an engineered expansion joint, such as one of the Schluter Dilex products.

How to Install a Tile Patio: A TileLetter Article


We highly recommend this article by David M. Gobis, Ceramic Tile Consultant.

Tile Patio Ideas and Inspiration


We recommend Houzz.com for images of tiled patios and an abundance of great design ideas. Click through the photos below to see examples!


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