The Short Answer

Begin by measuring each wall, gable and dormer separately. Then lay out the selected SteelTek Supreme profile using its actual panel length and exposure.

Estimate which offcuts can realistically be reused before adding a project-specific allowance for cutting errors, damage and future repairs. Finally, convert the requirement into full supplier order quantities.

Adding a percentage to the total wall area without testing the panel layout may produce a neat-looking number that does not correspond to what the project needs.

Start With Accurate Elevation Measurements

Divide the exterior into simple geometric shapes and calculate each one separately.

• Rectangle: multiply width by height
• Triangle: multiply base by height and divide by two
• Complex gable: divide it into rectangles and triangles, then add the areas

Record wall returns, bump-outs, dormers, porch enclosures and additions separately. Small sections often generate disproportionately high cutting waste.

Confirm Which SteelTek Supreme Profile Is Being Used

Gentek currently lists four SteelTek Supreme profiles with different exposures, panel lengths and pieces per carton:

One square is 100 square feet of nominal siding coverage. Verify current specifications and packaging before ordering because product information can change.

Horizontal and Vertical Profiles Generate Waste Differently

Horizontal SteelTek Supreme panels run across the width of the wall. Their waste is strongly influenced by wall length, lap placement and whether the remainder from one course can begin another.

Board and Batten runs vertically. Its waste is strongly influenced by wall height relative to the 10-foot panel length.

A waste factor that works for D4 Clapboard cannot automatically be applied to Board and Batten.

Why Wall Length Matters for Horizontal Siding

Gentek lists its horizontal SteelTek Supreme panels at 12 feet 6 inches long. A wall that is slightly longer than one panel may require a second piece in every course.

Whether the remainder is reusable depends on:

• The approved lap configuration
• Minimum usable piece length
• Required joint staggering
• Locations of windows and doors
• Where studs or approved fastening surfaces occur
• The appearance of laps on prominent walls

Do not assume every remainder is reusable. Mark proposed laps and offcut destinations on an elevation drawing.

Why Wall Height Matters for Board and Batten

Gentek lists SteelTek Supreme Board and Batten panels at 10 feet long. A wall slightly under 10 feet may use each panel efficiently. A wall slightly over 10 feet presents a different design problem.

Before estimating the material, determine whether the approved design will:

• Introduce a planned horizontal transition
• Use Board and Batten only within a defined wall section
• Change materials above or below the panel run
• Require a project-specific alternative detail

Do not invent an exposed horizontal splice simply to make a quantity calculation work. Confirm the allowed termination and transition details first.

Gables Can Produce Significant Cutting Waste

A gable may have a simple triangular area, but its sloped edges require a series of angled cuts.

Waste depends on:

• Roof pitch
• Gable width and height
• Horizontal or vertical panel orientation
• Window placement
• Whether opposite-angle cuts can be paired
• Minimum reusable offcut dimensions

Two gables with the same square footage can require different panel quantities if their shapes and openings differ.

Windows and Doors Do Not Always Reduce the Order Equally

Subtracting every opening from the gross wall area can underestimate material. Siding still has to run around those openings, and many resulting offcuts will be too short or incorrectly shaped for another location.

Small and medium windows often function as part of the cutting allowance rather than a full material deduction. Large garage doors and patio doors may justify a more meaningful deduction.

The correct approach is to map the panel cuts around each opening and calculate reusable material—not to apply one deduction rule blindly.

Small Wall Sections Can Be Material Inefficient

Narrow wall returns, areas between closely spaced windows and short sections beside garage doors may consume portions of full panels without leaving reusable remnants.

Measure these sections individually instead of assuming their small square footage makes them insignificant.

Small sections also contain more corners and channels relative to their siding area, increasing accessory and labor requirements.

Additions and Different Wall Planes Complicate Reuse

A home with several additions may contain walls of different heights and lengths. In theory, offcuts from one section could be used elsewhere. In practice, profile direction, lap location and visible weather exposure may limit reuse.

Keep separate cut lists for:

• Main house elevations
• Attached garages
• Porches and enclosed additions
• Dormers
• Gables
• Board and Batten accents

Combine the remaining material only after confirming that the offcuts meet the dimensions and installation requirements of another section.

Pattern and Joint Placement Are Aesthetic Decisions

A quantity-minimizing layout is not automatically the best-looking layout. Reusing every possible offcut can create a wall with numerous short pieces or distracting lap patterns.

Long front elevations deserve planned joint placement. Consider:

• Normal approach and street views
• Strong morning or afternoon light
• Locations of windows and doors
• Joint staggering
• Symmetry around prominent features

A small increase in material can sometimes produce a more composed elevation. That choice should be deliberate and priced transparently.

Allow for Handling and Installation Damage

SteelTek Supreme is designed for strength, but panels can still be scratched, bent or otherwise damaged during unloading, cutting and installation.

Extra material may be prudent where:

• Replacement material would require another special shipment.
• The project has many complex cuts.
• Long panels must be carried through restricted access.
• The color or profile may be difficult to source later.
• A future repair reserve is desired.

Extra material should be identified separately from expected cutting waste so the owner understands what will remain after installation.

Carton Rounding Can Be Larger Than the Waste Allowance

After calculating usable material and waste, convert the result into the cartons available from the supplier.

A project requiring slightly more than a full-carton increment may need another complete carton. That does not mean the entire additional carton is waste. The remaining panels can serve as repair stock if stored properly.

Estimates should show carton rounding separately so it is not confused with careless cutting.

Accessories Need Their Own Measurements

Panel square footage does not calculate starter strips, corners, J-channel, finish trim or custom-bent metal.

Measure accessories in linear feet or individual units:

• Base of each sided wall
• Inside and outside corners
• Window and door perimeters
• Gable slopes
• Soffit transitions
• Material changes
• Utility and fixture locations

Add accessory waste according to stock lengths, joint requirements and the number of corners—not the siding-panel waste percentage.

Create a Cut Plan for Complicated Elevations

A cut plan assigns full panels and significant offcuts to specific wall locations before installation.

A useful cut plan records:

• Each wall’s finished dimensions
• Panel direction and course count
• Window and door locations
• Required lap positions
• Gable cuts
• Reusable offcut dimensions
• Reserved replacement panels

This is especially valuable when material is special ordered or when another carton would cause schedule and freight consequences.

Store Leftover Panels Properly

Extra panels can be valuable for future repairs, particularly if a color or profile is later changed or discontinued.

Store retained material in a dry, protected location where panels will not be bent, scratched or exposed to chemicals. Label the material with the manufacturer, product, profile, color, purchase date and project address.

Do not leave unidentified scraps for the homeowner. A labeled full-length panel has far more future value than several damaged offcuts.

Waste Planning and Resale

A careful material layout supports consistent joints, balanced accents and clean architectural transitions. Those aesthetic details can strengthen the finished home’s curb appeal.

Saving leftover panels also gives a future owner a better chance of completing a compatible minor repair.

Neither efficient material use nor stored replacement stock guarantees a specific resale increase. They are practical signs of a thoughtfully managed project.

A Practical Quad Cities Recommendation

Quad Cities homes frequently include gables, enclosed porches, detached garages and additions constructed at different times. Those features make a single whole-house waste percentage especially unreliable.

For projects in Davenport, Bettendorf, Moline, Rock Island and surrounding communities, prepare elevation-by-elevation measurements and a profile-specific cut plan before ordering.

Suburban Wholesale & Supply can help contractors confirm current Gentek SteelTek Supreme profiles, packaging and related accessories. Final quantities remain the responsibility of the estimator and installer.