Hardboard

Summary

Hardboard is a dense, hard fiberboard made from exploded wood fibers highly compressed, at about 800 to 1,040 kg/m³. Lignin binds the fibers, and tempered hardboard resists water and impact, so it serves as siding, underlayment, and pegboard.

Cols

Image

HDF: high-density fiberboard
Wet process (Mason method): leaves one smooth side and one textured side from the drying screen
Dry process: smooth on both sides
Tempered hardboard: coated with linseed oil and baked
Perforated hardboard (pegboard): uniform holes for hanging tools

History and demand

Invention

1898: a similar product first made in England by hot-pressing waste paper
Early 1920s: improved high-temperature compression of wet pulp produced a denser board

Composition and production

Manufacturing process

Wood fibers exploded and compressed by wet or dry process; lignin binds the fibers, though resin is often added

Properties

Physical

Density: usually about 800 to 1,040 kg/m³ (50 to 65 lb/ft³), denser, stronger, and harder than particleboard and MDF

Thermal and moisture

Tempering improves water resistance, impact resistance, hardness, rigidity, and tensile strength

Standards

Material specifications

ANSI A135.4, A135.5, and A135.6: hardboard product types named in the building code

Uses in buildings

Building elements

Wall Cladding: tempered hardboard siding
Cabinetry and Casework: panels and backs

Pros and cons

Pros

Denser and harder than MDF and particleboard
Needs no added adhesive for binding
Tempered grades resist water

Cons

One textured face in the wet process

Sources

Wikipedia: Hardboard, https://en.wikipedia.org/wiki/Hardboard
UpCodes: 2024 IBC Chapter 23 wood, https://up.codes/viewer/department-of-defense/ibc-2024/chapter/23/wood
Wikimedia Commons: Hardboard.jpg, photo by Dave Pape (Public domain), https://commons.wikimedia.org/wiki/File:Hardboard.jpg