Thickness is one of the first numbers in a flooring specification, and one of the most often misread. A quotation that says “3/4 inch engineered oak” tells you the height of the board, but not how much of it is oak, what sits underneath, or whether that height suits the doors, stairs and subfloor on the project. This guide sets out the thicknesses we run and make to order, how overall thickness relates to the wear layer and the installation method, and what thickness means for refinishing over the life of the floor.
One board, three numbers
Every engineered board can be described by three measurements:
- Overall thickness. The full height of the board, from the face to the underside. This is the number that sets finished floor height.
- Wear layer. The thickness of the sawn oak face on top. This is the only part of an engineered board that can be sanded.
- Core. Everything below the wear layer: a stable plywood core in a 2-layer board, or a cross-layered core with a backing layer in a 3-layer board.
The first two are specified; the third is what remains. Two boards with the same overall thickness can carry different wear layers, so an RFQ should always state both numbers.
A solid board is simpler: oak runs through the full thickness, with no core, so overall thickness and usable oak are closely linked.
Thicknesses we run and make to order
These are the overall thicknesses listed on our Specify page. The two standard builds are already in current production; the others are made to order.
| Overall thickness | Status | Standard wear layer pairing |
|---|---|---|
| 3/8” (10mm) | Made to order | Confirmed on the specification |
| 1/2” (12mm) | Made to order | Confirmed on the specification |
| 9/16” (14mm) | Made to order | Confirmed on the specification |
| 5/8” (15mm) | Current production | 1/8” (3mm) sawn |
| 11/16” (18mm) | Made to order | Confirmed on the specification |
| 3/4” (20mm) | Current production | 1/4” (6mm) sawn |
| 13/16” (21mm) | Made to order | Confirmed on the specification |
For a figure not in this list, use the “Other thickness” field on the Specify page, so the sample is made to the real build.
Wear layers are sawn, from 0.6mm to 6mm. How each wear layer relates to sanding and to brushed textures is covered in our wear layer guide, so it is not repeated here.
What overall thickness decides on site
Overall thickness is mainly a building question: it decides how the new floor meets everything around it.
- Doors. Door leaves may need trimming, and thresholds need to suit the new height.
- Stairs. The top nosing and the landing floor have to meet flush. If stair treads are ordered with the floor, the drawing should show the finished floor height at the top and bottom of each flight. See oak stair treads that match the floor.
- Adjoining finishes. Tile, stone, carpet or an existing wood floor next door all set a target height at each threshold.
- Underlayments and adhesives. The finished height includes whatever sits under the board. The installer adds that to the overall thickness.
In renovation, the available height is the first thing to measure. A thinner engineered build, often 2-layer, is a practical choice where floor height is limited.
Thickness and installation method
Thickness and installation method have to be chosen together, and the installer makes the method decision.
Nail-down. Fasteners are driven at an angle through the tongue into a wood subfloor. The board has to have enough material above and below the tongue to take the fastener the installer intends to use. The installer and the fastener maker confirm the minimum for their system.
Glue-down. The board is bonded to the subfloor with a flooring adhesive, under the adhesive maker’s rules. Glue-down is common for engineered boards, including over concrete, and gives more room to choose a thinner build.
Floating. Our Tongue & Groove profile is machined on all four sides and is intended for glue-down or nail-down installation. If floating is being considered, raise it before the thickness is fixed, so all parties can agree whether the board and method suit each other.
State the intended method for each area in the RFQ. Our article on how installation shapes the spec covers method in more detail.
Thickness by construction
| Construction | How thickness is used | Where it fits |
|---|---|---|
| Solid | Oak through the full thickness | Narrower boards, where repeated sanding is a priority |
| 2-layer engineered | Sawn oak wear layer on a plywood core | Limited floor height; herringbone and chevron |
| 3-layer engineered | Wear layer, cross-layered core, backing layer | Wider boards and larger open areas |
The construction for a given thickness is confirmed on the specification, together with width and installation method. For the difference between the two engineered builds, see 2-layer vs 3-layer engineered oak.
Thickness and refinishing, in general terms
A floor can be maintained in two ways: recoating, where the finish is refreshed and very little wood is removed, and full sanding, where the face is taken back to bare wood. Thickness matters only for the second.
- On an engineered board, full sanding can only happen within the wear layer. A thicker overall board does not add sanding life unless the wear layer is also thicker.
- On a solid board, sanding can continue down toward the tongue, which is why solid has the greatest refinishing allowance of the three constructions.
- On any board, the usable depth is reduced by the position of the tongue and groove, by deep brushing that has to be sanded out, and by any unevenness in the installed floor.
We do not state a number of refinishes for any thickness, because how much oak each sanding removes depends on the floor, the equipment and the operator. Decide how the owner expects to maintain the floor, choose the wear layer for that plan, and the overall thickness for the building.
How thickness is held in production
Pressed blanks are sized, calibrated and sanded to the specified thickness, width and length, then checked against the order sheet. A wide belt sander calibrates thickness across the width of each board, and dimension inspection checks thickness and width against the order sheet as one of our quality checkpoints. Consistent thickness is what lets neighboring boards sit flush with each other when they are laid. The full route is shown on our Production page.
Mixing thicknesses in one project
More than one format or board size can be produced within one order under the same approved color reference. Where two formats meet, for example herringbone in a hallway and wider plank beyond, specify the same overall thickness for both if the floor must be level, or show the transition on the drawing.
Thickness checklist
Thickness is one line of the engineered oak flooring specification, and it is set together with the others.
| Question | Who answers it |
|---|---|
| How much height is available at doors, stairs and thresholds? | Buyer or architect |
| What is the subfloor, and which installation method will be used? | Installer |
| Does the method need a minimum thickness for fasteners or adhesive? | Installer, fastener or adhesive maker |
| How will the floor be maintained over its life? | Owner or specifier |
| Which overall thickness and wear layer, and is it a standard build? | Factory, confirmed on the specification |
| Do two formats in the project need to sit at the same height? | Buyer, with the installer |
Working with Vu Uy Wood
We manufacture solid and engineered French White Oak flooring to buyer specification in Song Than 3 Industrial Park, Ho Chi Minh City, and have done so since 2006. Our standard builds are 5/8” (15mm) and 3/4” (20mm), and other thicknesses from 3/8” (10mm) to 13/16” (21mm) are made to order. Set thickness together with construction, width and finish on the Specify page, and tell us the installation method and any floor-height limit so the build is reviewed with them in mind. We normally reply within one working day.