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Specify & buy

Lap Siding Profile and Exposure Guide

Choose lap profile and visible exposure while keeping wall scale, fastening zones, joints and package coverage consistent.

ProjectMeter Editorial TeamUpdated · How we review

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The practical starting point

Exposure is the visible height of each course, not always the full panel width. It controls course count, overlap and wall appearance, so use the exact product's exposure when converting wall area into packages.

STEP BY STEP

A decision you can check

  1. 01

    Select profile and texture

    Approve smooth, woodgrain, dutch lap or another profile on a full-size sample viewed outdoors.

  2. 02

    Record visible exposure

    Use the manufacturer's installed exposure and panel length for coverage, coursing and cut planning.

  3. 03

    Lay out elevations

    Align courses deliberately at windows, doors and attached walls while maintaining required overlaps and clearances.

  4. 04

    Count joints and accessories

    Plan end joints, joint treatment, starter, corners and opening trim according to the chosen system.

Write a specification someone else can check

Changing exposure changes course alignment even when net wall square footage stays the same.

Long panels reduce joints but need delivery, storage and handling space.

  • Select profile and texture
  • Record visible exposure
  • Lay out elevations
  • Count joints and accessories

Convert the decision into quantities

Enter the measured geometry in the Siding Calculator, replace defaults with the selected product coverage and round only at the final purchasable unit. List accessories and preparation materials separately so a coverage change does not silently scale unrelated items.

Field siding cannot compensate for missing kickout flashing, damaged sheathing or poor drainage details.

Verify at order and delivery

Check the exact local designation or product code, performance class, size, colour or batch where relevant, stated coverage, yield, density or capacity, ordered quantity and accessory compatibility on the written order. Inspect delivered exterior siding before installation and isolate damaged or mismatched material while return and replacement options remain open.

COMMON ERRORS

What usually throws the order off

  • Comparing only panel price
  • Treating material fire classification as wall approval
  • Using full panel width as exposure
  • Ignoring trim and water-management repairs

Frequently asked questions

What must the exterior siding specification identify?

Make the scope checkable against these decisions: select profile and texture; record visible exposure; lay out elevations; count joints and accessories. Record the exact local designation or product, performance class, dimensions, finish where relevant, accessories and controlling technical document.

Which calculator default changes after product selection?

Replace whichever default the exact exterior siding controls—coverage, yield, density, dimensions, package quantity or capacity—while keeping the verified project geometry unchanged.

Who should approve a substitution?

The owner and responsible designer or installer should confirm in writing that the substituted exterior siding preserves required performance, appearance, compatibility, installation method and documented supplier or project acceptance criteria.

Technical references

These references support the measurement and planning method. Product instructions, the site and applicable local requirements control the final installation.