How to Install Clay Roof Tiles From The Eave Up
Clay tile is the roof that outlasts everything under it, and it punishes shortcuts more than any other roofing material. Installed right, it runs 50 to 100 years with the underlayment replaced once or twice. Installed wrong, it leaks in the first storm and the fix means pulling courses off the roof.
Knowing how to install clay roof tiles starts below the tile. The deck, the underlayment and the battens do the waterproofing, and the tiles shed the sun and rain on top of that system. This guide covers a standard barrel (Spanish) tile installation on a new or stripped deck, at the slope and fastening a building department will pass.
The material alone runs $11 to $25 per square foot; labor doubles that. Doing it yourself saves the labor and takes three to five times longer than a crew, on a roof, with a live load limit that matters.
What You Need to Install Clay Roof Tiles
A 1,500 square foot roof needs roughly 1,500 clay tiles, about ten per square foot for barrel profile. Add 2,000 square feet of underlayment for a double layer, cap nails or tacks, one-by battens or treated lath, and corrosion-resistant screws or nails for the battens. Finish the list with self-adhering ice and water membrane for eaves and valleys, ridge tiles, ridge closure material, and a roof anchor system.
Tools: a ladder and roof jacks, a chalk line, a tape, a tile cutter or grinder with a diamond blade, a batten saw, and harnesses. Falling is the main way this project hurts someone; anchor before you work, every time.
Step 1: The Deck
The deck under clay tile must be solid sheathing in good repair, usually half-inch plywood or thicker boards. Clay weighs 800 to 1,575 pounds per square, so the framing needs to be designed for it. If the roof was framed for shingles, a structural engineer signs off before you buy tiles, not after.
Replace any soft, damaged or water-stained decking now. Every defect you cover becomes a repair you can’t reach for fifty years.
Step 2: Underlayment, Twice
Clay tile is not waterproof. Water that rides the wind past the tiles hits the underlayment, and that layer is the roof. Use two layers of Number 30 underlayment minimum, applied shingle-style from the eave up. Keep horizontal laps at four inches and end laps at six.
At the eaves and in every valley, a self-adhering ice and water membrane goes down first, running up the roof at least two feet past the interior wall line. Those are the two places a tile roof leaks, and the membrane is cheap insurance.
Fasten with cap nails, not staples through the felt. A staple tears the membrane; a cap holds it flat. Keep the surface smooth: a nail head proud of the deck telegraphs through the tile course above it.
Step 3: Battens
Battens are the grid the tiles hang from: one-by-two treated lath or a manufacturer’s batten system, laid horizontally across the roof with one batten per course. Learning how to install clay roof tiles is mostly learning to set this grid straight.
Spacing decides the reveal. Barrel tile hangs with a specific exposure, usually around twelve to thirteen inches; check the tile spec before you set the first batten, because moving battens later means pulling tiles.
Snap chalk lines, install the eave batten first, then work up the roof. Fasten every batten into rafter lines where possible. Straight battens, straight roof: take the time to check with a string line every four courses.
Step 4: Tiles From The Eave Up
This is where how to install clay roof tiles actually begins. Start at the eave with the starter course, set over a metal drip edge. Where the design calls for it, add an eave closure that keeps birds and wind-driven water out of the open barrel end.
The work itself is one motion repeated. Lay the first full course across the eave, then work up, course by course. Each tile hooks over the batten and laps the course below it. The pan channels water down between the tiles; the cap sheds it. Keep the laps consistent, or water sheets off a joint instead of running down the pan.
Nail or clip per manufacturer spec. Barrel tiles in most systems are nailed through the pre-drilled hole to the batten, one fastener per tile in standard exposure, two in high-wind zones. Over-driven fasteners crack tiles; hand-drive, do not gun.
Cut tiles at hips, valleys and rakes with a diamond grinder, outdoors, with a mask. A cut tile needs a clean edge; a snapped edge is a future crack. Fit valley metal first, then the cut tiles over it, keeping the valley open per spec.
Step 5: Ridge Tiles and Detail Work
Installing clay ridge tiles comes last, over a ridge closure or bedding mortar, per the system. This is the roof’s hat: it takes the wind first. Fasten every ridge tile; a bedded-only ridge is the one that comes off in a storm.
Walk the whole roof before you call it done: every lap consistent, every tile hooked, every cut deburred, no fastener heads proud, no gaps at valleys and flashings.
The Four Failures of Installed Clay Tile Roofs
Every premature leak after someone installs clay roof tiles comes from one of four places. Underlayment too thin or single-layer. Battens spaced by guesswork instead of the tile spec. Fasteners over-driven through the tile. And flashing installed around the tile instead of integrated before it.
None of those are visible from the ground on the day the roof looks finished. All of them are why a tile roof gets torn up at year fifteen instead of year eighty.
Related Guides
- Why Stucco Cracks After Winter — the seasonal movement that also moves your roof
- How to Build a Brick Archway — the masonry skills that pair with a tile roof
- Clay Tile Roof Cost — what the materials and labor really price out at
Questions
Can I install clay tile over existing shingles?
Some systems allow it with a batten assembly over the old roof, and most building departments do not. The weight doubles and the inspection usually fails. Strip the roof; a tile roof deserves a clean deck.
What slope does clay tile need?
Above about two-and-a-half to twelve, with double underlayment below four to twelve. Below that, tile is the wrong material and a low-slope membrane is the answer.
How do I walk on a tile roof without breaking tiles?
On the lower third of each tile, where it is supported by the course below, or on battens between tiles. Never on the crown of a barrel. Most installed-tile damage is foot traffic during later maintenance, not the original install.
How many tiles per square?
About ten per square foot for a standard barrel profile at typical exposure, so roughly a thousand for a thousand-square-foot roof, plus five to ten percent for cuts and breakage. Order by the spec sheet of the tile you bought, not by rule of thumb.