Fasteners may look like a minor part of an exterior project, but they are fundamental to ASCEND’s performance. The wrong head size, shank diameter, screw profile, staple crown, penetration depth, spacing, or driving pressure can affect panel movement, wind resistance, appearance, and warranty coverage.

Contractors should not select fasteners based only on what is already loaded in the siding nailer. The fastener must match ASCEND’s current installation requirements, the wall substrate, local environmental conditions, and the project’s wind-design requirements.

What Type of Nails Should Be Used?

ASCEND’s installation guide permits galvanized steel or other corrosion-resistant nails. The published nail specification calls for a 7/16-inch head and a 1/8-inch shank diameter.²

The broad head helps retain the nail hem without pulling through the slot. The fastener must also be long enough to pass through the ASCEND nail hem, weather-resistant barrier, nonstructural foam or existing materials, and still achieve the required penetration into solid nailable material.

Can Screws Be Used to Install ASCEND?

Yes. The ASCEND installation guide permits corrosion-resistant screws meeting the published specification. The guide calls for a No. 8 truss-head or pan-head, self-tapping sheet-metal-type screw.²

A truss or pan head provides a broader bearing surface than a narrow bugle-head screw. Contractors should avoid substituting drywall screws, deck screws, trim screws, or other narrow-head fasteners that have not been approved for the application.

Can Staples Be Used?

Yes. ASCEND permits staples when they meet the manufacturer’s published requirements. Staples must be at least 16 gauge, have a 7/16-inch crown, and use a semi-flattened-to-elliptical cross section.²

Staples must not be driven so tightly that the crown clamps the nail hem against the wall. The cladding must remain free to move within the fastening slots.

Why Must the Fasteners Be Corrosion Resistant?

Exterior fasteners are exposed to changing temperatures, humidity, incidental moisture, and chemicals present in some treated lumber, flashing products, and wall materials. A fastener that corrodes can lose strength, stain the exterior, damage surrounding components, or reduce long-term attachment performance.

ASCEND therefore requires galvanized steel or another corrosion-resistant fastener material. The appropriate corrosion protection may depend on the building location and surrounding materials.

How Much Fastener Penetration Is Required?

ASCEND generally requires at least 1-1/4 inches of fastener penetration into solid nailable material, such as wood sheathing or framing members.³

The required penetration is measured only within material capable of securely holding the fastener. Non-nailable layers do not count toward the minimum.

For example, if the wall includes one inch of non-nailable foam over the structural substrate, the fastener must pass through that foam and then penetrate at least 1-1/4 inches into the approved nailable material. The foam thickness cannot be included in the 1-1/4-inch calculation.

What About Wood-Furring Applications?

ASCEND’s installation guide states that the product may be used in qualifying furring applications with 3/4-inch fastener penetration. The guide also directs installers to consult ASCEND technical support for wind-load resistance associated with 3/4-inch penetration into 1-by-3 wood furring.³

Contractors should not automatically reduce penetration to 3/4 inch on every furred wall. The furring size, spacing, attachment to the structure, cladding profile, fastener spacing, building height, and wind-design pressure must all be evaluated.

Should ASCEND Be Hard-Nailed?

No. ASCEND must not be hard-nailed. The installation guide requires at least 1/32 inch of clearance between the fastener head and the nail hem so the panel and accessories can move as temperatures change.³

Driving the fastener tightly against the nail hem pins the material to the wall. As the cladding expands or contracts, that restriction can create buckling, distortion, stress at the slots, cracked nail hems, separated locks, or uneven wall appearance.

Can a Pneumatic Nailer or Stapler Be Used?

Yes, provided the powered fastening system is adjusted correctly. ASCEND instructs installers using power nail guns or staplers to set the air pressure so the required 1/32-inch clearance remains between the fastener and nail hem.³

The crew should test the tool on a sample or inconspicuous panel before beginning full production. Air pressure can change with hose length, compressor cycling, temperature, tool maintenance, and the density of the fastening substrate.

Where Should the First Fastener Be Placed?

Fastener positioning depends on the ASCEND profile or accessory being installed. For 12-inch Board & Batten, the first fastener is placed in the uppermost portion of the top full unobstructed slot. Remaining fasteners are placed in the center of the nail slots.⁴

Several vertical accessories use a similar hanging method: the top fastener supports the piece while the remaining centered fasteners allow movement. Other details may require center-pinning at a specific location.

Contractors should never apply one fastening pattern to every panel and accessory. Follow the profile-specific instructions for Plank, Board & Batten, corners, H-trim, lineals, J-channel, starter strips, and finish trim.

How Far Apart Should ASCEND Fasteners Be?

ASCEND commonly uses fastener spacing of 8 to 12 inches on center, depending on the panel, accessory, substrate, and required performance. The Board & Batten guide directs installers to place remaining panel fasteners every 8 to 12 inches in the centers of the nail slots.⁴

The 7-inch Plank overlap procedure also includes specific fastening instructions, including staggered fasteners at the joint. Contractors must follow the complete guide rather than reducing the system to one universal spacing number.⁵

Does Tighter Fastener Spacing Improve Wind Resistance?

In tested assemblies, closer fastener spacing may produce higher published wind-load resistance. For example, ASCEND’s current Board & Batten technical summary lists different wind-load values for 12-inch and 8-inch nail spacing over the referenced sheathing assembly.⁶

That does not allow contractors to invent a wind rating by simply adding more nails. Wind performance depends on the complete tested assembly, including fastener type, substrate, penetration, panel profile, spacing, wall construction, and installation method.

Can ASCEND Be Fastened Through Foam Sheathing?

A fastener may pass through foam sheathing, but the foam thickness does not count toward the required penetration into solid nailable material. The fastener must be long enough to pass through the cladding, foam, and other non-nailable layers before achieving the required embedment in the approved substrate.

Thick exterior insulation can therefore require significantly longer fasteners or a designed furring assembly. Contractors should verify the wall construction instead of guessing from the visible exterior surface.

Can ASCEND Be Fastened Over Existing Siding?

Existing siding does not automatically provide an acceptable fastening substrate. If an overlay installation is permitted, fasteners must still reach the required solid nailable material, and the wall must meet the current ASCEND installation instructions and applicable building codes.

Existing siding thickness, fanfold insulation, foam, uneven surfaces, deterioration, and concealed moisture damage all affect the fastener length and suitability of the wall.

Should Fasteners Be Driven Through Other Nailing Flanges?

No. ASCEND’s profile-specific guidance warns installers not to fasten through the nailing flanges of other materials or accessories. Overlapping flanges can restrict movement, distort components, or create an incorrect wall buildup.⁴

When panels and accessories intersect, installers must follow the published sequencing, clearances, and flange-cutting details rather than stacking and fastening through multiple moving components.

What Fasteners Are Used for the Starter Strip?

The ASCEND starter strip is fastened every 8 inches, with the fasteners staggered between the upper and lower rows of slots. The guide calls for 1-1/4-inch penetration into the studs or approved nailable substrate and the same 1/32-inch clearance beneath the fastener head.⁷

The starter strip must be level. A secure but uneven starter will still produce a poor installation because every course above it follows the starting reference.

What About Trim Nails?

Certain Board & Batten partial-panel details may require a trim nail to hold a cut section near the top. The guide instructs installers to drill a 1/8-inch pilot hole in the specified board section, use a trim-nail punch, and avoid hard-nailing the fastener.⁸

This is a specific finishing detail—not permission to face-nail complete panels wherever the installer finds it convenient.

Common ASCEND Fastening Mistakes

How Can Contractors Verify Fastener Penetration?

Contractors should identify every layer of the wall before selecting the fastener length. Do not rely solely on blueprints when working on an older remodeling project. Field verification may reveal foam, existing siding, multiple sheathing layers, furring, or wall conditions that change the required length.

1. Identify the ASCEND profile and nail-hem depth.
2. Measure the thickness of existing siding or cladding layers.
3. Measure foam, fanfold, or other non-nailable materials.
4. Identify the actual nailable substrate.
5. Add the required penetration into that substrate.
6. Select the appropriate corrosion-resistant fastener length.
7. Complete a test installation.
8. Verify movement and inspect the rear penetration when practical.

Should Contractors Keep Fastener Records?

Yes. Fastener documentation can be valuable if the project later develops a wind, movement, or warranty concern. Record the manufacturer, fastener type, material, dimensions, length, spacing, penetration, substrate, and tool settings.

How Should Contractors Explain ASCEND Fasteners?

The Bottom Line

ASCEND Composite Cladding may be installed with galvanized steel or other corrosion-resistant nails, screws, or staples. Nails require a 7/16-inch head and 1/8-inch shank. Screws should be No. 8 truss-head or pan-head self-tapping sheet-metal screws. Staples must be at least 16 gauge with a 7/16-inch crown and the published cross-sectional shape.

Standard applications generally require at least 1-1/4 inches of penetration into solid nailable material. Non-nailable foam and existing materials do not count toward that penetration. Qualifying wood-furring applications may use 3/4-inch penetration, but their wind-load performance and complete assembly must be verified.

Fasteners must never clamp the panels tightly. Leave at least 1/32 inch between the fastener head and nail hem, follow profile-specific spacing, and verify the entire wall assembly before loading the nailer. A premium cladding system can still fail when the crew treats fastener selection as an afterthought.