How a Tile Roof Is Installed in Arizona, Step by Step

Why the Install Matters More Than the Tile

A concrete or clay tile is tough. It shrugs off UV, doesn't burn and sheds most of the water that hits it. But tile isn't a sealed surface. Wind-driven monsoon rain and water running down a valley get under it, and the layers beneath are what keep that water out of the house.

In the Phoenix metro, summer roof surfaces regularly reach 150 to 170°F, so those hidden layers age faster than the tile above them. That's why so many Valley tile roofs need their underlayment replaced while the tile still looks fine.

A tile roof that lasts is mostly about the parts you never see: a solid deck, the right underlayment installed to its warranty rules, real metal flashing at every transition, and tiles fastened for the Valley's wind loads. The steps below follow that order.

Step 1: Pick the Tile and Check the Weight

Most Valley homes use concrete tile, made to the ASTM C1492 standard. Clay tile (ASTM C1167) costs more and is more fragile underfoot. Both come in three broad shapes: S-tile or barrel, flat, and low-profile. HOAs often control the color and profile, so check your design guidelines before you fall for a sample. Our concrete vs. clay comparison covers the trade-offs.

Weight is the first engineering question. One tile maker's published specs put its standard-weight concrete tiles at roughly 900 to 970 pounds per 100 square feet of roof, and its lightweight versions at roughly 550 to 720 pounds. IKO lists its Cambridge architectural shingle at about 230 pounds per 100 square feet. Going from shingle to standard tile can add roughly four times the roofing weight.

The building code requires the existing structure to carry the new roof's load. On a home that was framed for tile, re-tiling is straightforward. On a home framed for shingles, switching to tile usually needs an engineering check of the rafters or trusses, and in most Valley cities it needs a building permit because it's a change to a heavier material. Lightweight tile is sometimes the answer when the framing can't take standard weight.

Step 2: Permits, HOA Approval and Scheduling

Permit rules vary by city. A like-for-like re-tile or a tile lift-and-relay is permit-exempt in many Valley cities, including Phoenix, Mesa, Chandler, Gilbert, Peoria and Surprise, while Queen Creek and Apache Junction list roofing as permitted work. A switch from shingle to tile, or replacing sheathing or framing, usually needs a permit even in exempt cities. When a permit is issued, the city may inspect at set stages. Scottsdale, for example, inspects permitted reroofs three times: the sheathing, the flashing and underlayment, and a final.

HOA approval is a separate step from the city. Most master-planned communities require architectural review before you change roof color, profile or material, and the city doesn't enforce HOA rules for you. We can pull together the product sheets and samples an HOA usually asks for.

Timing matters too. Underlayment shouldn't sit exposed to the sun for long. TRI-BUILT's HT SA warranty, for example, requires the underlayment to be covered within 180 days and not exposed to UV for more than 180 days, and SwiftGuard's warranty excludes product left uncovered for more than 180 days in total. In the Valley's summer sun, good crews load and set tile soon after the underlayment goes down rather than leaving it baking for weeks.

Step 3: Tear-Off and Deck Preparation

On a re-roof, the old tile (if it's being replaced), underlayment, battens and flashings come off down to the deck. On a lift-and-relay, the tile is lifted and stacked on the roof first, and everything under it is removed.

With the deck exposed, the crew checks every sheet:

• soft, delaminated or rotted plywood or OSB around old leaks, valleys and penetrations
• sheathing that's loose or under-nailed
• gaps at sheathing edges and damage at the eaves and fascia

Damaged sections are cut out and replaced with sheathing of the same thickness, fastened to the framing below. The code allows tile over solid sheathing or spaced structural sheathing boards, and older Valley homes have both. Vent and plumbing penetrations are checked for proper framing at this stage, before anything covers them.

This is also when hidden problems show up that a ground-level estimate can't see. Good contracts explain up front how deck replacement is priced, so you're not negotiating halfway through the job.

Step 4: Underlayment, the Real Waterproofing

Underlayment is the layer that keeps water out of the house. The code sets minimums: tile needs a slope of at least 2.5:12, and from 2.5:12 up to 4:12 the underlayment has to be doubled. Products must meet tile underlayment standards or be listed alternatives.

Manufacturers then add their own rules, and the warranty depends on following them. We install several products, each with different terms:

• Fontana Vulca Seal G40: a "No Leak" warranty of 10 years for a single layer or 20 years for a double layer, on slopes of 4:12 or more. The warranty bans staples as underlayment fasteners, requires an extra ply at least 18 inches wide in all valleys, eaves, rakes and around every penetration, requires deck and tile flashing at every penetration (including solar mounts), and has to be registered within 30 days of installation.
• SwiftGuard synthetic tile underlayment: warranted to shed water for as long as the tile's warranty runs, up to 50 years.
• TRI-BUILT HT SA self-adhered synthetic: a 50-year warranty that transfers automatically to later owners.

Installation starts at the eave and works up, each course lapped over the one below, with extra protection in valleys and around penetrations. Ask your roofer which product you're getting, whether it's single or double layer, and who registers the warranty. Our underlayment guide compares the options.

Step 5: Flashing at Every Transition

Most tile roof leaks start at a transition, not in the open field of tile. That's where metal flashing does the work.

• Valleys: the code calls for corrosion-resistant metal of at least No. 26 gauge, extending at least 11 inches each side of the centerline with a splash-diverter rib at least 1 inch tall, and a 36-inch strip of underlayment beneath on slopes of 3:12 and steeper. Valleys carry a large share of a roof's water during a monsoon downpour, so this is no place to save money.
• Walls: where a roof meets a wall, base flashing and counter flashing (or a stucco stop) keep water from running behind the stucco. A kickout flashing at the bottom of a sidewall turns water away from the wall.
• Penetrations: plumbing vents, exhaust vents and solar mounts each get a deck-level flashing and a tile-level flashing, so water that gets past the tile still meets metal.
• Chimneys and wide curbs: a cricket on the high side of anything more than 30 inches wide keeps water from pooling behind it.

On a lift-and-relay, the code requires flashings to be rebuilt or reused only if they're in good condition and suited to the new roof. We replace pipe jacks, valley metal and sidewall flashing whenever they're rusted, cracked or undersized.

Step 6: Battens, Layout and Loading

Many tile roofs are hung on wood battens: strips nailed horizontally across the roof that give each tile a lip to hook over and set the exposure (how much of each tile shows). Some systems use raised or counter-battens that leave a gap for water and air to move underneath. Others fasten tile directly to the deck. Which is used depends on the tile profile, the slope and the manufacturer's instructions, and it affects the fastening rules below.

Batten spacing has to match the tile's exposure exactly. A small error repeated across 20 courses ends up as crooked rows and short tiles at the ridge, so crews measure the run from eave to ridge and snap chalk lines before nailing anything.

Next comes loading: stacks of tile are lifted onto the roof and spread across the planes so no area of framing is overloaded. Then the first course goes on at the eave, with an eave closure or bird stop to keep birds and pests out of the openings under barrel and S-tile, and the field tile works upward course by course.

Step 7: Fastening for Monsoon Wind

A common myth is that every tile on every roof must be nailed. The real rule is more specific. The code's tile attachment table says:

• every tile within the perimeter zone has to be fastened, meaning at least three tile courses and not less than 36 inches from hips, ridges, eaves and rakes
• on solid sheathing without battens, every tile gets at least one fastener
• on battens at slopes under 5:12, field tiles may not need fasteners, while steeper roofs follow the table
• where wind speeds exceed 130 mph or the roof is more than 40 feet above grade, the manufacturer's instructions govern

Fasteners must be corrosion-resistant nails of at least 11 gauge with a 5/16-inch head, long enough to go 3/4 inch into the deck or through it, or tie wire of at least 0.083 inch. The Valley's design wind speed is typically 115 mph, but monsoon gusts and outflow winds are what pull tiles loose, so we follow the tile maker's fastening instructions and the industry installation manual, which often call for more than the code minimum. Hip and ridge tiles are fastened as well as bedded.

Step 8: Hips, Ridges and Final Details

Ridges and hips cap the joints where roof planes meet. Traditionally they're set in a bed of mortar; many installs now use a foam adhesive or a dry ridge system with a nailed ridge board and a ventilated closure, depending on the manufacturer. Either way, the cap tiles are fastened as well as bedded, so a wind gust can't lift a whole run.

At valleys, field tiles are cut to a clean line along the metal, leaving an open channel of metal so water and debris flow freely. Fontana's underlayment warranty, for example, doesn't allow closed valleys and calls for at least 2 inches between opposing tiles. Cut tiles are made with a diamond blade so edges don't crack. Around vents and solar mounts, tiles are trimmed to fit over the upper flashing.

If you have solar, the panels come off before work starts and go back on at the end. Our detach and reset service is $150 per panel when it's done as part of a re-roof or repair.

The job finishes with a cleanup of the roof, gutters and yard, and a walk-through of the finished roof, ideally with photos of the stages you couldn't see from the ground: the deck, the underlayment and the flashings.

Timeline, Cost and What to Ask Your Roofer

A typical tile installation takes 3 to 5 days, weather and size permitting. Larger homes, many hips and valleys, deck repairs or a city inspection between stages can add time.

Typical installed prices in the Phoenix metro:

• New concrete tile roof: about $6.50 to $10.50 per square foot, roughly $15,000 to $35,000 for a typical full tile replacement
• New clay tile roof: about $8.50 to $14 per square foot
• Concrete tile lift-and-relay (keep your tile): about $4 to $7 per square foot, roughly $10,000 to $22,000
• Clay tile lift-and-relay: about $5 to $8.50 per square foot

Prices vary with size, pitch, access, tile profile and how much deck repair is needed. Our roof cost calculator gives a quick range, and a free estimate gives a firm one.

Questions worth asking any tile roofer:

• What underlayment, how many layers, and who registers the warranty?
• Are valley, wall and pipe flashings new or reused?
• How is deck replacement priced if we find damage?
• Does my city require a permit, and who pulls it?
• What workmanship warranty do you give? (Ours is 10 years, with a 25-year option.)

Tile work also isn't a DIY project. It means carrying heavy stacks on a hot, steep surface, and federal OSHA rules require fall protection for residential roofers working six feet or more above a lower level. Arizona also requires a licensed contractor for most roofing jobs; ours is ROC #358508.

Related

• Roof Installation
• Tile Underlayment Replacement
• Professional Inspection
• Arizona Underlayment Guide
• Concrete vs. Clay Tile
• Tile Roof Cost in Arizona
• Roofing in Phoenix
• Roofing in Scottsdale
• Roofing in Mesa
• Roofing in Gilbert
• Roofing in Chandler
• Roofing in Peoria