OWENS CORNING
SHINGLE INSTALLATION

Owens Corning permits several wood-based sheathing types, provided they meet APA – The Engineered Wood Association standards. Solidly sheathed decks are required to prevent structural deflection and fastener withdrawal.

The 1/8-inch minimum gap is a critical engineering safeguard. Wood absorbs moisture and expands — without this gap, panels buckle and create ridges that telegraph through the shingles and compromise the secondary water barrier.

Before any roofing components are applied, the installer must inspect the deck for structural integrity. The deck must be clean, dry, and free from protrusions such as old nails or debris that could puncture the underlayment.

If the existing deck consists of spaced boards with gaps exceeding 1/4 inch, those gaps must be repaired or the boards replaced to ensure a continuous nailable surface. Sheathing thickness and installation must also comply with local building codes, as these determine the ultimate nail-holding capacity of the assembly.

In regions prone to ice damming, Owens Corning requires a self-adhered ice and water barrier such as WeatherLock or Titanium PSU30. This barrier must start at the eave edge and extend upslope to a point at least 24 inches beyond the interior wall line, measured horizontally.

These products meet ASTM D1970 standards and are applied directly to the clean, dry deck surface before the field underlayment.

For slopes of 4:12 and greater, Owens Corning recommends synthetic underlayments like RhinoRoof or ProArmor. These outperform traditional #15 felt in tear strength and UV stability, and must meet ASTM D226, D4869, or D8257 standards.

On low slopes, water sheds more slowly, increasing moisture contact time. Underlayment must be installed with a 19-inch overlap for a 36-inch wide roll — effectively creating a double layer of protection across the entire deck. Alternatively, a full layer of self-adhered ice and water barrier may be used.

SureNail Technology integrates a tough, woven engineered reinforcing fabric into the nailing area of the shingle. This fabric creates a "triple layer" of reinforcement where the fabric overlays the common bond — the area where the two layers of the laminated shingle are adhered together.

• Fastener Holding Power: The woven fabric increases resistance to nail heads pulling through the shingle mat during high-wind events.
• Uplift Protection: In a standard 4-nail application, Duration shingles with SureNail are warranted for winds up to 130 mph — a performance level that typically requires 6 nails for standard shingles.
• Installation Consistency: The highly visible fabric strip provides a clear target for the installer, ensuring nails land precisely in the common bond area rather than in the single-layer headlap.

The performance of the SureNail zone is entirely dependent on correct fasteners and driving technique. Fasteners must be driven flush with the shingle surface:

• Under-driven nails cause "tenting" — the shingle above bridges over the raised nail head, losing sealant contact with the course below.
• Over-driven nails fracture the fiberglass mat, negating the structural benefit of the SureNail fabric.

For standard applications, the Duration and Oakridge series use a 5 5/8-inch exposure with a recommended 6 1/2-inch offset between courses. Variations of 4–8 inches are acceptable, provided end joints are no closer than 2 inches from a fastener in the shingle below.

The Berkshire collection (slate-profile shingles, 360 lbs/square) requires a fundamentally different installation method: the single-column vertical racking method. Unlike diagonal application used for standard laminates, Berkshire shingles are applied in vertical columns from eave to ridge.

• Exposure: 8 3/8 inches
• Offset: 4 3/4 inches
• Chalk Lines: Both vertical and horizontal lines are essential for maintaining alignment.
• Right Edge Technique: In odd-numbered courses, the right edge of shingles is initially left unfastened, allowing the adjacent column's shingle to slide underneath. A single fastener then secures both shingles simultaneously.

The closed-cut valley begins with a 36-inch wide valley liner centered in the valley. Shingles from the first plane are laid across the valley, extending at least 12 inches past the centerline. These shingles are fastened only on their outer edges — no nails within 6 inches of the valley center.

Shingles from the second plane are trimmed 2 inches back from the centerline. The upper corner of each trimmed shingle is clipped at a 45-degree angle to divert water toward the valley center, and the end is embedded in a 3-to-4-inch wide bead of roofing cement.

The IRC has required drip edges at eaves and rakes since 2009. The sequence differs at each location:

• At eaves: Drip edge applied directly to deck → underlayment installed over drip edge → water flows off underlayment into gutter.
• At rakes: Underlayment applied first → drip edge installed over underlayment → prevents wind-driven rain from entering the edge of the underlayment.

Starter shingles (OC Starter Strip Plus) must be trimmed 6 to 6.5 inches at the rake to prevent end joint alignment with the first course. They should overhang the drip edge by 1/4 to 3/4 inch (or 1/2 to 1 inch if no drip edge is present). Fasteners go 2 to 3 inches from the eave edge.

Step flashing is installed with each course of shingles where a roof plane meets a vertical sidewall. Units are typically 10 inches long × 7 inches wide (for 5-inch exposure). The flashing is nailed to the roof deck only — never to the wall. This allows independent movement during thermal expansion or seismic activity.

Chimney flashing requires a four-part system:

The 1/150 rule dictates that there should be 1 square foot of Net Free Area (NFA) for every 150 square feet of attic floor space. For a balanced system, no more than 50% of the NFA should be at the ridge (exhaust); 50% or more must be at the eaves or soffits (intake).

VentSure ridge vents are installed by cutting a slot in the roof sheathing:

• Ridge board roof: 1-inch slot on each side of the board.
• Engineered truss roof: Single 2-inch slot centered over the ridge.
• Slots must stop at least 6 inches from rake edges to prevent leaks.
• Apply ASTM D4586-compliant asphalt cement to "picture frame" the slot opening before installing the vent — this fills gaps created by the texture of architectural shingles.
• For VentSure 4-foot strip, leave a 1/8-inch gap between sections for thermal expansion.

Asphalt shingles become brittle below 40°F and the factory sealant strip may not thermally activate immediately. When temperatures drop below this threshold:

• Hand-Seal: Each shingle must be hand-sealed with four 1-inch diameter dabs of asphalt cement placed evenly across the shingle, approximately 1 inch from the leading edge.
• Thermal Gapping: Install shingles with a 1/16 to 1/8-inch gap at end/butt joints to allow for expansion when temperatures rise.
• Hip & Ridge Caps: These must be bent over the ridge peak and are especially prone to cracking in cold. Store them in a warm environment until just before installation.

In many jurisdictions — including Illinois — a building permit is required for any re-roofing or roof recovery project. Contractors must be licensed and provide proof of project valuation. Inspections are required after permit approval to verify code-mandated elements: ice/water shield, flashing, and ventilation.

Owens Corning's Total Protection warranty requires use of OC shingles, underlayment, starter shingles, and hip/ridge shingles as a system. Additional warranty conditions:

• New flashing must be installed unless existing flashing is in like-new condition and meets proper gauge requirements.
• Shingles from different lot numbers should not be mixed — shade variations may become visible across the roof plane.