Framing

Steel Flooring Joists

Light gauge steel C-section joists and bearers for a level, dimensionally stable subfloor that stays straight for the life of the build.

Ready to price your steel flooring joists? Quotes are typically turned around within 48 hours..
Overview

Steel Flooring Joists & Bearers

Timber floor systems can warp, twist, or sag over time. Trueline steel flooring joists and bearers hold their dimensions permanently, giving a consistently level floor for tiling, flooring and fit-out, without the callbacks.

  • ✓C150–C250 sections to suit span requirements
  • ✓Won’t warp, twist or sag over time
  • ✓Consistent, level subfloor for any finish
  • ✓Engineered bearer and joist spacing
G350C150–C250Z275 Coated
System Components

Everything in a Steel Joist Floor

Every member is engineered, cut to length, and labelled to your floor layout.

Joists
C-section members at your engineered spacing, carrying the flooring and floor loads.
Bearers
Heavier members that support the joists and transfer load to piers, stumps, or walls.
Rim & End Joists
Close off the floor edge and give a solid base for wall frames.
Blocking & Bridging
Stiffen the floor and keep joists straight and aligned.
Trimmers
Frame openings for stairwells and floor voids.
Connections
Joist-to-bearer brackets and fixings detailed to your engineering.
Full Specification

Material Specification

SectionThicknessGradeCoating
C1501.5mmG350Z275
C2001.9mmG350Z275
C2502.4mmG350Z275
Steel vs Timber

Steel vs Timber Floor Joists

A floor is only as good as what’s underneath it. Here’s how a steel joist floor compares.

Comparison
TrueLine Steel
Timber
Level
Stays level for the life of the build
Can sag, cup or bow over time
Shrinkage
None
Shrinks as it dries, loosening fixings
Squeaks
Far fewer, with no shrinkage to loosen fixings
Common as timber dries and moves
Termites
Completely immune
Needs treatment and barriers
Moisture
Won't rot or swell
Can rot in damp subfloors
Consistency
Every member identical
Varies piece to piece
Where It's Used

Applications

Light gauge steel floor systems for every build type.

Residential
Elevated & slab-alternative floors
Commercial
Suspended commercial floors
Rural & Sheds
Mezzanine & storage floors
Industrial
Heavy-duty industrial flooring
Floor to Roof

One Supplier, One Complete Frame

Order your steel flooring joists together with our wall frames, roof trusses and battens, all detailed to work as one system. It’s how we help builders deliver steel frame homes Perth WA families can rely on, with one supplier, one order and one delivery schedule.

Slab Alternative

When a Steel Joist Floor Makes Sense

Most Perth homes sit on a concrete slab, but it isn’t always the best or cheapest option. A suspended steel floor is often the smarter choice for:

Sloping Blocks
Build level over the fall with less retaining and earthworks.
Upper Floors
The structural floor for double-storey homes and additions.
Flood-Prone & Regional Sites
Lift living areas above flood levels and ground moisture.
Difficult Soils
Carry loads on piers where your engineer recommends against a full slab.
Extensions & Renovations
Match the raised floor levels of older homes.
Mezzanines & Storage
Add usable floor area in sheds and warehouses.
Built for WA

Engineered for WA Conditions

    • ✓ Termite-Proof: Steel joists and bearers can’t be eaten by termites
    • ✓ Moisture-Resistant: No rot or swelling in damp subfloors
    • ✓ Coastal Sites: Coating and detailing confirmed for your exposure
    • ✓ Bushfire-Prone Areas: Non-combustible steel suited to BAL construction
  • ✓ Engineered Loads: Designed for your floor coverings, fit-out and use
Our Process

From Plans to a Level Floor

Send Your Plans
Floor plan, floor levels and footing layout, plus your site address.
Floor Design & Engineering
Joist sizes, spacing and bearer layout engineered to your spans and loads.
Quote in 48 Hours
Direct, itemised pricing with no middleman markup.
Fabrication
Steel flooring joists and bearers cut to length and labelled to your layout.
Delivered to Site
Packed for efficient delivery across Perth and regional WA.
Why Trueline

Why Builders Choose Us Over Other Steel Floor Joists Suppliers

01
Direct-Import Pricing
No local-manufacture markup passed on to you.
02
Engineered Per Job
Joist sizes and spacing designed for your plans, not a standard table.
03
Whole-Frame Supply
Floor-to-roof framing for steel frame homes Perth WA builders trust, in one order.
04
Perth-Based Support
Talk to a real person at our Koondoola office.
15
Homes Supplied
Port Hedland
50%
Faster Framing
vs Timber
48hr
Quote Turnaround
Direct Pricing
100%
AS1397
Compliant
FAQ

Wall Frame Questions, Answered

Yes. A suspended steel floor is a proven alternative to a slab, especially on sloping blocks, flood-prone sites, or where your engineer recommends piers over a full slab. It can also reduce earthworks and retaining. Your engineer will confirm the best footing system for your site.

Your floor plan, finished floor levels, footing or pier layout, and the site address. Tell us your floor coverings too, because heavy finishes like tiles and stone change the design. If your plans aren't final, send what you have, and we'll tell you what's missing.

Not when it's designed properly. We size the joists and spacing to your spans and loads so the floor stays firm underfoot. If you're planning long open-plan spans, heavy stone benchtops or a large bath, tell us so we can allow for them.

Structural particleboard and plywood suit most areas, and fibre cement sheet is common under tiles and in wet areas. Sheets are fixed with self-drilling screws, plus construction adhesive where the manufacturer recommends it. Timber, vinyl, carpet and tiles then go on as normal.

Squeaks usually come from timber shrinking and loosening fixings over time. Steel doesn't shrink, so there's far less movement to cause them. On upper floors, insulation between the joists also helps reduce footstep noise below.

Yes. The Building Code requires ventilation under suspended floors to control moisture, regardless of the framing material. Good airflow keeps the subfloor dry and protects the flooring above, so plan vents or open sides into your design.

Not in a dry, well-ventilated subfloor. Our floor sections carry a Z275 galvanised coating. If your site is near the coast, or the subfloor is likely to stay damp, send us the address, and we'll confirm the right coating before you order.

Yes, but plan it early. Mark your waste pipes and cable routes on your plans so they're allowed for in the design. Never cut or enlarge holes in joists or bearers on site without approval from the designer or an engineer.

Often, yes. External floors face the weather, though, so coating, drainage and waterproofing need extra attention, and balconies and cantilevers need specific engineering. Tell us the floor is external when you enquire and we'll confirm the right specification.

Yes. We're steel floor joists suppliers to builders, developers and owner-builders across Perth and regional WA. Floors arrive cut and labelled to your layout, and we'll talk you through the order so nothing is missed.

Ready to spec your steel flooring joists?

Send us your plans or floor layout for a direct, fast quote.

Related Products
Wall Frames
Send Your Plans
Steel wall frames that sit straight on a level floor.
Roof Trusses
Send Your Plans
Engineered steel trusses for any roof shape.
Battens
Send Your Plans
Hat-section battens for roof sheeting and ceiling linings.
Get Pricing

Enquire About Steel Wall Frames

Trueline Steel support
Why Enquire Direct?
  • ✓Fast, direct pricing — no middleman markup
  • ✓Quotes typically turned around within 48 hours
  • ✓Custom heights and stud spacing to your plans
  • ✓Steel frames Perth-wide, plus delivery across regional WA
Prefer to talk it through? Call (08) 9249 3969 — Mon–Fri 7am–5pm, Sat 8am–12pm.