Vinyl Siding Terms

Understanding some basic vinyl siding terms will make you a more informed consumer. Our library of siding terminology will have you sounding like a siding professional in no time.

Vinyl Siding Terms

ASTM D3679
The benchmark against which certified vinyl siding is measured by the Vinyl Siding Institute (VSI). It provides an industry standard of quality for siding products, based on factors such as impact resistance, weatherability, resistance to wind load and extreme temperatures, and uniformity of product manufacturing.

A material installed between the exterior of a building and the back of the vinyl siding product to provide a uniform surface upon which to install vinyl siding, as well as an added layer of insulation.

The section along the bottom edge that locks onto the panel preceding it. Buttlocks are found on vinyl siding panels, soffits and accessories, across from the nailing hem slots.

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The open area within the corner posts or trim into which panels are inserted. There are different names of trim pieces, depending on their shape, and the names refer to the actual shape of the trim piece (such as F-channel, J-channel, etc.). Double channel lineal is an accessory that joins adjoining soffit panels.

A section of panels in a row that runs from one side of the building to another (or from top to bottom if it is vertical siding) that is one panel wide.

Also known as a ‘lug’. Refers to the tab created on a piece of vinyl siding using a snap lock punch that can be used if the nailing hem has been removed. It is used to lock a piece of vinyl siding into place.

Drip Cap
An accessory that ensures that water does not get underneath vertical siding panels, but rather drips away from them. This trim piece is also known as ‘head flashing’.

EPS Foam
EPS, or extruded polystyrene, is a rigid plastic used in foam insulation that backs insulated vinyl siding. It is a durable product that is very weather resistant, provides insulating properties, and is used in a wide range of applications.

The front side of the panel or soffit.

Face Nailing
Not widely used in installation, this process fastens siding by nailing directly through the face (or front) of a vinyl siding panel, rather than through the nail hem slots.

Refers to the trim that covers the edges of the roof rafters. The fascia board attaches to the edges of the roof rafters (between the soffit overhang and the actual roofing material) and the fascia cover (also known as the fascia cap) covers the board.

Finish Trim
Used to secure a panel when the top lock has been removed. Also known as ‘utility trim’ or ‘undersill trim’.

Also known as a ‘nailing hem.’ (see definition below) Contains the nailing slots to secure the panels in place.

A thin piece of aluminum that is installed behind certain trim, accessories and areas of the building to resist water penetration into the building. Flashing is often used around windows, and behind corner posts, channels, etc.

Furring Strip
A thin strip of wood (usually 1″ x 2″) attached to the exterior wall prior to installation to even the underlying surface so that installation is even and level.

Head Flashing
Also known as a ‘drip cap’ (see definition above).

Pricing Information

Low To Mid Range: $1.50 – $3.50 psf
(This is the price per square foot installed)

Mid To High End: $3.50 – $5.50 psf
(This is the price per square foot installed)

Price on 2000 Sq. Ft.: $3000 – $11000

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Additional Vinyl Siding Terms

Overlapping the edges of adjoining panels or trim pieces to leave room for expansion and contraction of the vinyl.

Also known as a ‘crimp’ (see definition above).

To make angled, beveled cuts on the edges of siding panels or accessories to create a better looking finished appearance.

Nailing Hem
Also known as a ‘flange’ (see definition above).

An exact 90 degree vertical measurement from a horizontal level surface.

A measurement of the level of insulation a product delivers. The higher the value, the more insulation offered by the product. Numerous factors, both intrinsic and extrinsic to the product, determine the r-value.

The molding installed along the sloping sides of a roof or gable to cover the edges of the siding.

To run a sharp object along the face of a panel to weaken the surface. This allows the material to be cleanly bent and then broken with ease. Scoring can be done with a scoring tool, or with a utility knife, awl or other very sharp instrument.

A thin material, usually wood, used to even the underlying surface so that siding can be installed evenly.

Snap Lock Punch
A tool that creates a tab on the top of a vinyl siding piece to lock it into place if the nailing hem is removed.

The accessory pieces that cover the underside of an overhang, eave or cornice. Soffits are usually installed as panels, like the siding itself, but the panels are installed perpendicular to the siding, from the edge of the exterior wall to the fascia.

Starter Strip
Something attached to the exterior of the building to ensure that the first course of siding is even and level during installation.

A weather resistant and waterproof material that is installed over the backerboard and under the vinyl siding panels.

Undersill Trim
Also known as ‘finish trim’ or ‘utility trim’ (see definition below).

Utility Trim
Also known as ‘finish trim’ or ‘undersill trim’ (see definition above).

Weep Holes
Openings in the panels or accessory pieces that allow for water runoff.

Zip Lock Tool
A tool used to unlock one piece of siding from the adjoining piece. The tool is run along the edge of the siding to unlock the two pieces.