NRCA Tile Installer cheat sheet

OSHA fall protection trigger for steep-slope roofs (slope greater than 4:12) is 6 ft; conventional fall protection must be in place before work begins.

Warning line plus safety monitoring system is permitted only for low-slope roofs (4:12 or less) and only when no other fall protection is feasible.

Guardrail top edge height: 42 in. plus or minus 3 in., with a midrail at approximately half height and a 4 in. minimum toe board.

Personal fall arrest system: full-body harness, anchor rated 5,000 lb per worker, and maximum free-fall distance of 6 ft; keep total fall distance clear of lower levels.

Ladder extension above the eave or landing: 3 ft minimum; ladder setup angle 4:1 (1 ft out per 4 ft of height).

Roof brackets and roof jacks must be nailed into structural members, not sheathing alone; space per manufacturer and never exceed the rated load.

Lanyard attachment point must be at or above shoulder level (D-ring in back) to limit free fall and swing-fall hazard.

Hot-work and open-flame rules: keep a fire extinguisher within reach, clear combustibles, and maintain a fire watch during and after torch or kettle work.

Material hoisting: never exceed the ladder or scaffold load rating; keep the ground area below barricaded during raising and lowering.

Minimum roof slope for tile without special detailing is 4:12; slopes from 2.5:12 to 4:12 require a doubled underlayment or manufacturer-approved low-slope assembly.

Deck deflection limit for most tile assemblies: L/360 for the total load (dead plus live) unless the manufacturer requires stiffer.

Solid sheathing for tile: minimum 15/32 in. plywood or 7/16 in. OSB, fastened with 8d common nails at 6 in. on center at edges and 12 in. in the field.

Sheathing gaps: 1/8 in. between panel edges for expansion; stagger end joints and support all edges on framing.

Underlayment laps: 6 in. on sides and 12 in. at ends for steep-slope; laps must shed water down-slope, upper sheet over lower.

Ice dam protection (where required): self-adhering membrane from the eave edge to at least 24 in. inside the warm wall line.

Eave and rake overhangs must be sheathed and underlayment carried over the fascia edge with a metal drip edge.

Ventilation: net free vent area of 1/150 of the attic floor area when balanced (1/300 with balanced intake and exhaust and a vapor retarder).

Fastener penetration through sheathing: at least 3/8 in. beyond the underside of the panel or per code; never overdrive and crush the panel.

ASTM C1167 covers clay roof tile; Grade 1 is the highest grade, with freeze-thaw durability tested per the standard.

ASTM C406 covers concrete roof tile; Grade A is the highest grade.

ASTM C836 is the specification for liquid-applied waterproofing membranes used in tile roof assemblies.

ASTM A653 specifies hot-dip galvanized steel; G90 coating is a common minimum for roof flashings.

S-profile tile is a high-profile interlocking tile; flat or low-profile tile requires a steeper minimum slope or a built-up underlayment system.

Tile weight reference: concrete tile typically 8-12 lb per sq ft; clay tile 6-10 lb per sq ft; verify the actual product data for structural design.

Tile should be tested for water absorption and freeze-thaw resistance; absorption over about 6% raises frost damage risk in cold climates.

A square of roofing equals 100 sq ft; tile coverage per square varies with exposure, so order by the manufacturer's pieces per square.

Tile fasteners: corrosion-resistant nails or screws; 11-gauge or heavier, long enough to penetrate sheathing at least 3/4 in.

Step flashing: one piece per course of tile, minimum 4 in. wide by 4 in. high, lapped 2 in. and set under the tile above and over the tile below.

Chimney flashing sequence: apron at the bottom, step flashing on the sides, and a cricket (saddle) on the up-slope side when the chimney width exceeds 30 in.

Valley flashing: metal valley minimum 24 in. wide (12 in. each side) for open valleys; lap each course so water flows over the lower piece.

Pipe and vent penetrations: use a lead or neoprene boot or a proprietary flashing collar, with the upper flange tucked under the tile above.

Drip edge: required at eaves and rakes; metal should extend at least 1/4 in. below the sheathing edge and behind the underlayment at the eave.

Kick-out flashing at sidewalls: diverts water away from the wall and into the gutter; a missing kick-out is a common leak and rot source.

Headwall and sidewall flashing: use a two-piece counterflashing system so the upper piece is removable for maintenance.

Waterproofing at low-slope transitions (2.5:12 to 4:12): use a self-adhering membrane at least 12 in. on each side of the transition and lap per the manufacturer.

Tile layout: establish a true vertical centerline and lay tile from the center out, or from a full-tile edge, so cut tiles fall at the rakes.

Course exposure: measure the tile length minus headlap; the manufacturer's exposure determines pieces per square and total order quantity.

Fastening rule: fasten every tile in high-wind zones (typically 90 mph basic wind speed or greater) and at hips, ridges, and perimeter; otherwise follow the manufacturer's schedule.

Nail placement: drive fasteners through the nail holes so the tile hangs; do not overdrive, and leave the head slightly above the tile surface.

Nail penetration into sheathing: minimum 3/4 in. for nails; screws must engage the framing or sheathing per the manufacturer's listing.

Wind uplift design: use the code's wind speed map and the tile manufacturer's uplift rating; add fasteners at corners and edges where uplift is highest.

Tile spacing: maintain the manufacturer's recommended side lap and head lap; tight butting can crack tiles and block drainage.

Cut tiles at rakes and hips should be fastened with two fasteners and supported fully by the underlayment and flashing.

Eave closure: use a bird stop or eave closure to block wind-driven rain and prevent birds from entering the tile profile.

Rake tile: set rake tiles over a rake trim or flashing, fastened to the barge rafter or fascia, with the underlayment carried over the edge.

Hip and ridge: fasten hip and ridge tile with two fasteners per piece and use a hip/ridge batten or mortar bed per the manufacturer.

Hip and ridge ventilation: ridge vent area should balance with soffit intake; net free area per code (1/150 or 1/300 rule).

Valley types: open metal valley (visible metal) vs. closed-cut valley (tile from one slope crosses the valley and is cut along the other slope).

Open valley width: typically 3-4 in. of exposed metal at the valley center, with tile cut back at least 2 in. from the centerline on each side.

Valley underlayment: install a minimum 24 in. wide membrane or metal valley under the tile, extending at least 12 in. up each slope.

Ridge cap fastening in high-wind zones: use screws or ring-shank nails and consider a mechanical ridge vent system rated for the design wind speed.

Hip and ridge mortar: use a Type N or S mortar with proper mixing; keep weep holes clear so moisture can escape.

Steep-slope tile (4:12 and steeper): use battens or a counter-batten system where required by the manufacturer to create a drainage plane.

Low-slope tile (2.5:12 to 4:12): use a double-layer underlayment or a proprietary waterproofing membrane assembly and follow the manufacturer's low-slope detail.

Slopes below 2.5:12 generally cannot use standard tile without a special engineered assembly; verify the manufacturer's written approval.

Tile over battens: battens must be fastened into framing or sheathing per the manufacturer; do not rely on sheathing alone for battens.

Cold-climate detail: ice dam membrane at the eave plus a drainage plane above the underlayment reduces ice-dam back-up leaks.

High-wind application: use the manufacturer's high-wind fastening schedule and consider foam or mechanical closures at eaves and rakes.

Tile at transitions to low-slope roofs: use a minimum 12 in. vertical or horizontal transition membrane and a cricket or diverter where water ponds.

Ventilation and condensation: a ventilated air space above the underlayment helps dry the assembly in humid climates; follow the manufacturer's vent detail.

Broken tile replacement: lift the tile above, slide the new tile into place, and fasten through the existing nail holes; never nail through the tile below.

Cracked tile repair: replace rather than seal when the crack crosses the tile body; sealant is a temporary fix only for hairline cracks.

Leak diagnosis: check flashings, valleys, and penetrations first; these cause more leaks than tile field failures.

Moss and algae: use a low-pressure wash and a manufacturer-approved cleaner; never use a high-pressure washer that can strip the tile surface.

Mortar repair at hips and ridges: remove loose mortar, clean the joint, and repack with a compatible mortar; keep weep holes open.

Fastener corrosion: replace corroded fasteners with hot-dip galvanized or stainless steel; corrosion often indicates a long-term moisture problem.

Walking on tile: step on the headlap area over the batten or framing, not on the unsupported tile center, to avoid cracking.

Maintenance schedule: inspect after major storms and annually; clear debris from valleys and gutters to prevent water back-up.

Roof plan reading: identify slope indicators, ridge lines, valleys, and penetration symbols; slope is expressed as rise:run (e.g., 6:12).

Slope factor formula: slope factor = sqrt(1 + (rise/run)^2); multiply the plan area by the slope factor to get the actual roof area.

Roof area estimation: plan area x slope factor = actual area; add 10-15% waste for hips, valleys, and cuts.

Tile quantity: pieces per square from the manufacturer's exposure data; order by the square, then convert to pieces and add waste.

Underlayment quantity: one roll typically covers 4 squares (400 sq ft) for 36 in. wide material; account for laps.

Code compliance: IRC Chapter 9 covers roof assemblies; check the local jurisdiction for amendments and wind/seismic requirements.

Wind design: use the code wind speed map and the manufacturer's uplift rating; fastening schedules must match the design wind speed.

Inspection checklist: verify sheathing thickness and fastening, underlayment laps, flashing heights, and tile fastening before sign-off.

Bid documents: confirm the scope includes tear-off, deck repair allowance, flashing replacement, and disposal; hidden conditions are common in re-roofing.