Timber Flooring Over Concrete Slabs in Perth: The Direct-Stick Guide
Most Perth homes are built on a concrete slab, so if you want a real timber floor the question is not whether you can lay timber flooring over concrete, but how. The most popular method in Western Australia is direct-stick: gluing the timber boards straight down to the slab for a solid, quiet floor that feels like part of the house. Done properly it is a superb result; done without the right slab preparation it is the number one way timber floors fail. This guide explains how direct-stick works in Perth, what has to happen to the slab first, and what it costs.
What is direct-stick flooring?
Direct-stick means bonding each timber board to the concrete slab with a flexible flooring adhesive, rather than laying it as a floating floor over an underlay. The result is a floor that is fixed to the building: it feels solid and quiet underfoot, with none of the slight hollowness or movement a floating floor can have. It is the go-to method for real timber flooring over a slab, and it is especially well suited to engineered timber.
Direct-stick or floating: which is right?
Both are valid over a Perth slab. A floating floor clicks together over an underlay and is quicker to lay, which suits laminate, hybrid and floating bamboo. Direct-stick glues real timber down for a more solid, permanent feel and is the preferred method for engineered and solid timber. If you want the authentic weight and silence of a timber floor, direct-stick delivers it; if speed and budget lead, a floating product may suit. Our best flooring for Perth homes guide weighs up the wider choice.
The slab prep that decides everything
This is the part that separates a floor that lasts decades from one that lifts within a year. Moisture is the leading cause of timber floor failure, and a concrete slab holds and releases moisture long after it looks dry. Before any timber goes down, a proper installation covers three things:
- Moisture testing. The slab’s moisture is measured before installation, not assumed. Industry practice is to check the relative humidity within the slab and the moisture content of the top layer, and to document the readings. A concrete moisture content of around 5.5% or below is a commonly used threshold, and a new slab often needs months to cure to that point.
- Flatness and soundness. The slab must be structurally sound and flat, with only minor deviation (a common guide is no more than about 3 mm over a 3-metre radius). High spots are ground down and low spots filled so the finished floor is even and fully bonded.
- A clean, barrier-ready surface. The slab is cleaned of dust, old adhesive, paint and sealers so the glue bonds properly. Where testing indicates, an approved moisture barrier is applied to the slab first to protect the timber from residual moisture.
Skipping these steps is exactly how timber floors cup, gap or lift. Getting them right is why a professionally direct-stuck floor stays flat and quiet for the long haul.
Engineered or solid timber for direct-stick?
Both can be direct-stuck, but engineered timber is usually the better choice over a Perth slab. Its stable, multi-layer core moves far less with seasonal humidity changes than a solid board, which lowers the risk of cupping and gapping on a slab. Premium species are available both as engineered boards and as genuine solid timber, in the iconic WA hardwoods Jarrah and Marri and other native species such as Blackbutt, Spotted Gum and Tasmanian Oak. Engineered is usually the easier choice over a slab, while solid boards can also be direct-stuck for a genuine hardwood result.
The direct-stick process, step by step
- Assess and test the slab for moisture, flatness and soundness, and document the readings.
- Prepare the surface by grinding high spots, filling low spots, and cleaning off dust, adhesive and coatings.
- Apply a moisture barrier where the testing calls for one.
- Glue down the boards with a flexible flooring adhesive, working to a planned layout.
- Leave an expansion gap around the perimeter so the floor can move slightly with the seasons.
- Finish — pre-finished boards are ready to walk on once the adhesive has cured (typically about a day), while raw boards are sanded and coated on site.
- Fit skirting to cover the expansion gap and complete the room.
Why is direct-stick so popular in Perth?
It comes down to how Perth homes are built. The great majority sit on a concrete slab on ground, which is the ideal base for a direct-stuck timber floor. The method gives homeowners a real timber floor with a solid, high-end feel, without a raised timber subfloor. Paired with the right moisture management for Perth’s warm, dry summers and cooler, wetter winters, it is a proven, long-lasting result, which is why it has become the default for timber over slabs across the metro area.
What does timber flooring over concrete cost in Perth?
Supplied and laid, engineered timber starts from $86/m², while premium species engineered boards run from $115/m² for Blackbutt and Spotted Gum and from $135/m² for Jarrah and Marri. If you are supplying your own timber, installation alone starts from $32/m². Final rates also depend on the install method (floating or direct-stick), and slab preparation and any moisture barrier are assessed on site, since they depend on the condition of your slab. For the full breakdown by floor type, see our Perth flooring cost guide, and remember new skirting boards finish the job over the expansion gap.
Getting it done right
Direct-stick is a method where the preparation matters as much as the boards, and it is one part of the wider flooring installation process. The safest path is a local installer who tests your slab, preps it properly, and stands behind the result. Perth Flooring & Skirting is a local, fully insured business based in Pearsall with public liability cover up to $5 million, and we assess the slab as part of quoting your floor.
Start with the online quote tool for a fast estimate, and we will confirm the slab preparation your home needs at the on-site measure.
Timber flooring over concrete in Perth: frequently asked questions
Can you lay timber flooring over a concrete slab?
Yes. The most popular method in Perth is direct-stick, where the timber is glued straight to the slab after the slab has been moisture-tested, levelled and prepared.
Do you need a moisture barrier under timber on concrete?
Often, yes. Ground-level slabs generally need an approved moisture barrier where moisture testing indicates it, because residual slab moisture is the leading cause of timber floor failure.
How long does a new concrete slab need to dry before flooring?
A new slab can take months to reach an acceptable moisture level, which is why it is tested rather than assumed before any timber is laid.
Is engineered or solid timber better over concrete?
Engineered timber is usually the better choice over a slab because its stable core resists the seasonal movement that can cup or gap a solid board, though solid timber can also be direct-stuck.
How do I get a price for timber over my slab?
Use the online quote tool for a fast estimate, and the slab preparation is confirmed at the on-site measure.