Fasteners for Cedar Siding: What Kind of Nails and How to Use Them

Installation, Care, and Maintenance of Wood Shake and Shingle Siding gives handy advice to the homeowner who wants to install cedar siding.

Nail placement for cedar shingles up to 10 inches (254 mm) wide requires two corrosion-resistant nails driven 3/4 inches (19 mm) from each edge and 1 inch (25 mm) above the exposure line. For shingles wider than 10 inches (254 mm), drive two additional nails approximately 1 inch (25 mm) apart near the center.

nails-and-screws_101875306-[Converted]

Corrosion-resistant fasteners.

To decrease the chance of splitting the shake or shingle, fasteners should be blunted siding nails and should be ring- or twist-shank to improve holding. A ring-shank nail will have adequate holding power if it penetrates ¾ inch (19 mm) into the wood.

Corrosion-resistant nails are needed to avoid iron stains caused by extractives in the wood and corrosion by acid rain, salt air, etc. Certain preservative- and fire-retardant treatments also may be corrosive. Check with the product supplier for recommendations on proper fasteners for their products. Non-corrosive siding-nails are available in hot-dipped galvanized (as per ASTM A 153/D) Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware and type 304 or 316 stainless steel. Additional information may be available from supplier websites, and some suppliers may have additional requirements.

 

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Finishes for Cedar Siding: Finish Selection

Installation, care, and maintenance of wood shake and shingle siding instructs us in the proper finish to apply to cedar siding. Wide selections of oil- and latex-based finishes are available for shakes and shingles. Oil-based finishes are solvent-borne, and latex-based are water-borne; however, in recent years the solvent-borne finishes often have co-solvents in them to make them water soluble. As with any other wood product, shakes and shingles can be finished with water-repellent preservatives (WRP) (clear and lightly pigmented), semitransparent stains, solid-color stains, or paints.

Water-Repellent Preservatives

Water-repellant preservative is a generic term that describes a clear penetrating finish that traditionally was formulated with about 10% to 20% oil or alkyd binder, 1% to 3% wax or similar water repellent, a preservative, and an organic solvent such as mineral spirits or turpentine. The finish does not contain a pigment and gives a natural wood appearance.

Figure-5.-Newly-installed-shingle

Newly installed shingle siding with transparent water-repellent preservative finish.

The low wax content in some of the traditional WRP formulations made it possible to use them for pretreatment of wood prior to painting. They were also an excellent pretreatment for shakes and shingles prior to installation. Bundles of shingles could be dipped. Most of the finish was absorbed into the end grain at the butt end of the shake or shingle and gave years of protection by minimizing end-grain water penetration.

To meet stringent air quality requirements, these solvent-borne types of WRPs are no longer available. They have been largely replaced by water-borne formulations and formulations having low organic solvents content. Many of these formulations are intended for use on wood decks, but they can also be used on siding. These finishes often are tinted with a small amount of pigments, UV stabilizers, and other additives to improve their service life.

Figure-13.--tinted-water-repellent

Shingles treated with tinted water-repellent preservative.

They give some water repellency and inhibit mold and algae growth on the lateral surface. If used on single-story structures having wide roof overhang, they give about 2 to 3 years of service, depending on exposure.

 

FPL’s Fire Safety Team Recognized: FPL's Length of Service Ceremony Remembers this Special Recognition

Following up on yesterday’s post about fire safety, Lab Notes is pleased to announce a special recognition award mentioned at FPL’s length of service award ceremony today.

FPL’s Fire Safety team in FPL’s Durability and Wood Protection Research unit was recognized by the Greater Madison Federal Agency Association (GMFAA) for building effective relationships in and out of the Forest Service. Team members include Robert White (deceased), Mark Dietenberger, Laura Hasburgh, Keith Bourne, and Charles Boardman. The team endured losses over the past few years: reductions in staff and research funding, disruption to research from decommissioned facilities, and most importantly, the recent, sudden loss of their group’s leader, Robert White.

robert-white

Dr. Robert White died peacefully on March 19, 2014, while at work.

Through all this adversity, the team has been productive, including contributing to codes and standards and software programs that predict residential fire damage. Many thanks to this team of researchers who work hard to keep the public safer.

Direct Application of Shakes and Shingles: More Techniques for the Homeowner

According to the publication Installation, Care, and Maintenance of Wood Shake and Shingle Siding, for direct application, shakes or shingles are applied directly over properly installed and flashed Type 30 felt (or house wrap as approved by local codes). Shakes and shingles may be single-coursed, stagger-coursed, or double-coursed. The double-course application permits the use of a lower grade for the first layer and a greater exposure of the higher quality second layer of shake or shingle. Pressure-impregnated preservative-treated products can be used in these applications.

With some knowledge and skill, shakes can also be applied over existing siding.

overbrick

Rain screen technique over brick. Used with permission
from Cedar Shake and Shingle Bureau Exterior and Interior Wall Manual.

 

Shakes and shingles may be used to cover existing wood beveled siding, masonry, or stucco. The shakes or shingles can be applied directly over the existing siding; however, rain screen application is necessary over brick, stucco, and foam sheathing. If applied directly over composite wood siding products such as hardboard siding, use longer fasteners and nail through the siding to the underlying sheathing. The brick molding around windows and doors will have to be extended, so it may be better to increase the wall thickness even more and use the rain-screen application. Fasten vertical furring strips to the underlying wallstuds, fasten horizontal boards to the vertical strips, and nail the shakes or shingles to the horizontal nailing strips.

Direct Application of Shakes and Shingles

According to Chris Hunt and his co-authors on Installation, Care, and Maintenance of Wood Shake and Shingle Siding, shakes or shingles can be applied directly over properly installed and flashed Type 30 felt (or house  wrap as approved by local codes). Shakes and shingles may be single-coursed,

stagger-course

Single-coursed application of shingles. Used with permission from Cedar Shake and Shingle Bureau Exterior and Interior Wall Manual.

stagger-coursed,

Stagger-course

Stagger-course application. Used with permission from
Cedar Shake and Shingle Bureau Exterior and Interior Wall Manual.

or double-coursed.

Double-course

Double-course application. Used with permission from
Cedar Shake and Shingle Bureau Exterior and Interior Wall Manual.

The double-course application permits the use of a lower grade for the first layer and a  greater exposure of the higher quality second layer of shake  or shingle. Pressure-impregnated preservative-treated products can be used in these applications.

So the homeowner who wants the beauty and natural look of cedar siding can use these techniques to cover existing siding.