Impact Resistance
One type of damage associated with conventional vinyl siding is cracking and denting when struck by severe hail, a mower-driven rock or other high-impact events. For a vinyl siding product to be certified through the Vinyl Siding Institute's (VSI) Product Certification Program, the vinyl material must absorb a specified level of impact without rupturing. But there are real-world events that can exceed this level of impact resistance.
The addition of FullbackV® Siding Insulation to vinyl siding panels allows them to absorb considerably higher levels of impact without cracking or denting. As a result, each panel becomes more durable at the time of installation and for the life of the product.
Durability and Impact Resistance
Compressive Resistance and Flexural Strength.
Fullback®V is a closed cell, lightweight and resilient, foamed plastic composed of hydrogen and carbon atoms. The mechanical strength of Fullback®V varies with its density. The most important mechanical property of Fullback®V insulation and building products is its resistance to compressive stresses, which increase as the density becomes higher. Fullback®V has a compressive resistance between 10 - 60 psi for most construction applications. Within that range Fullback®V can be produced to meet specific strength requirements.
Optimum performance of a load carrying insulation is often related to both strength characteristics and resiliency. Resiliency is the ability of a material to recover its strength following deformation caused by stress. If greater strength and rigidity are needed, compressive resistance up to 60 psi is available by increasing the density of EPS insulation to meet virtually any compressive strength requirement.
Compressive Strength
Maximum fiber stress developed in a specimen just before it cracks or breaks in a flexure test. Flexural yield strength is reported instead of flexural strength for materials that do not crack in the flexure test. An alternate term is modulus of rupture.
Flexural Strength
Maximum fiber stress developed in a specimen just before it cracks or breaks in a flexure test. Flexural yield strength is reported instead of flexural strength for materials that do not crack in the flexure test. An alternate term is modulus of rupture.
Density
Is the mass per unit volume of a plastic, expressed in pounds per cubic foot. The insulation industry methods to determine density are outlined in ASTM C303.
Standard densities, available within the insulation industry today, generally range from .90 to 1.80 pounds per cubic foot. The reason for greater density is related directly to increased performance required by the product. The greater the density, the better the compressive strength, flexural strength, "R"-value, etc. Density increases have a direct correlation to cost and therefore don't always justify the increase.
The majority of Fullback®V products are made at .90 density. Accordingly, if you cut a Fullback®V block 12" x 12" x 12" it should measure a cubic foot and weigh .90 of a pound.
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Specification Test Standard for Impact Resistance Testing of Rigid Roofing Materials by Impacting with Freezer Ice Balls, Class No. 4473, FM Approvals (2005) (Modified) (The test procedure was modified byp lacing the specimens in a vertical position with the impact normal to the specimen. Each specimen received one impact. (click here for full report) |