Home / How it is made
From plank to finished topHow Hevea slabs and countertops are made in a Vietnamese workshop
Nine stages turn a rough-sawn rubberwood board into a finished slab or butcher block top. Knowing them tells you what to ask for. At every stage there is a photo that shows whether the piece you will receive is on track.
What happens, and the photo to ask for
Typical for Vietnamese Hevea workshops. The workshops we match you with send photos of the real piece. These are the moments worth seeing before you approve.
| Stage | What happens | Photo or record to ask for |
|---|---|---|
| 01 Treatment | Rough-sawn Hevea boards are treated with boron salts by dip, diffusion or vacuum pressure soon after sawing. Rubberwood holds starch and sugar, so untreated boards stain or attract insects within days. | Which treatment product and method the mill used, and its data sheet if the top is for a kitchen. |
| 02 Kiln drying | Boards are stacked with spacers and dried in a kiln to 8 to 12% moisture content. Thicker stock needs a slower schedule and a conditioning phase to release drying stress. | A moisture meter reading on the boards for your order, with the meter in the photo. |
| 03 Selection and grading | Dry boards are cut to length, defects are removed and the faces are sorted into Grade A, B or C by knots, mineral streaks and colour. | The boards laid out side by side before glue-up, in natural light. |
| 04 Glue-up | Boards or staves are edge-glued and clamped: full-length staves, finger-jointed staves or wide boards matched for a single-slab look. Wide live-edge tops are usually glued from several boards. | The clamped panel and the glue lines, so you can see how many boards make the top. |
| 05 Flattening | Panels are calibrated on a wide belt sander. Cupped, twisted or live-edge slabs are surfaced on a CNC router first, which handles shapes a sander cannot. | A straight edge across the face, and the measured thickness at several points. |
| 06 Edges, epoxy and cut-outs | Live edges are cleaned back to sound wood by hand, cracks and voids are filled with clear or tinted epoxy, and sink, cooktop and grommet openings are cut to your template. | Each filled area, and the cut-outs against your template before finishing. |
| 07 Sanding | The face is sanded through a grit sequence, typically from 80 or 100 grit up to 220 or 240, so each stage removes the scratches of the one before. | The raw sanded face under a low, raking light, which shows scratches a flat light hides. |
| 08 Finishing | Raw sanded, food-safe mineral oil blend, hardwax oil, matte polyurethane or a custom stain, chosen for where the top will be used. Every face and cut edge is sealed for wet areas. | The finished top in the same light as the approved sample. |
| 09 Crating | Tops are wrapped, edge protected and crated or palletised in heat-treated wood marked to ISPM 15 for export. | The top in the open crate, and the ISPM 15 mark on the crate. |
Kiln drying sets how the top behaves in your room
Below the fibre saturation point, roughly 25 to 30% moisture content, wood starts to shrink. Drying from there down to 8 to 12% is the slow part, and rushing it locks stress into the board that shows up later as checks, cup or a crack when the slab is resawn. A useful primer: wood drying.
More in the journal: kiln drying wood slabs and wood slab moisture content.
| Thickness | Typical kiln time to 8 to 12% | Risk if rushed |
|---|---|---|
| 25 mm | about 1 to 2 weeks | End splits, mild surface checks |
| 38 mm | about 2 to 4 weeks | Surface checks, casehardening |
| 50 mm | about 3 to 6 weeks | Honeycomb, deep checks, casehardening |
Typical ranges. Species, kiln and starting moisture change them, and many careful workshops air dry thick stock before it goes into the kiln.
Glue-up decides the look
- Full-stave blockFull-length staves glued edge to edge. Long, calm grain lines with no end joints on the face. Needs long clear boards, so it costs more.
- Finger-jointed blockShorter pieces joined end to end with interlocking finger joints. A busier look and a lower cost, and length is not limited by board length.
- Slab-style topWider boards selected and matched for a single-slab look, straight or live edge.
- Live-edge slabKeeps the natural bark line on one or both long edges. Hevea trees are slim, so wide live-edge tops are usually glued from several boards.
Side by side: finger joint vs full stave. What a good glue line looks like: butcher block glue lines.
CNC router or wide belt sander
Two ways to make a glued top flat and to thickness. The right one depends on the piece, and many slabs see both.
| Factor | CNC router surfacing | Wide belt sanding |
|---|---|---|
| Handles cupped or twisted slabs | Yes | Only with a flat reference face |
| Typical thickness tolerance | about 0.2 to 0.5 mm | about 0.1 to 0.3 mm |
| Surface it leaves | Tool ridges, needs sanding | Smooth, ready for finer grits |
| Live-edge and epoxy-filled slabs | Works well, on cured epoxy | Limited, belts clog on epoxy |
| Best for | Rough, warped and thick slabs | Butcher block panels and flat boards |
Typical figures. Ask the workshop for the thickness tolerance it will hold on your top and how it will be measured.
The last stage, chosen for the room
Order a finished sample, about 200 x 200 mm, and judge it in your own light. Finishes in detail: wood countertop finishes.
| Raw sanded | For buyers or installers who finish on site |
|---|---|
| Food-safe mineral oil blend | Prep surfaces and chopping zones, re-oiled regularly |
| Hardwax oil | Natural matte look, better water resistance, spot repairable |
| Matte polyurethane | Bar tops, desks and serving islands, the hardest wearing |
| Custom stain | Matched to joinery or a designer colour reference |
| Epoxy stabilisation | Live-edge slabs with cracks, knots or voids, clear or tinted |
Process FAQ
How long does it take to make a Hevea slab or countertop?
Production typically runs 3 to 5 weeks once the order and the sample are approved. Drying is not inside that window when the workshop holds dry stock, so ask whether your thickness is in stock or has to be dried first, which can add weeks for 50 mm and thicker.
What moisture content should a Hevea top be shipped at?
Typically 8 to 12%, set toward the low end for heated or air conditioned interiors. Air drying alone settles wood at the moisture of outdoor air, often 12 to 18%, which is too wet for most homes. Ask the workshop for a meter reading on your actual piece.
Is a CNC-flattened slab better than a sanded one?
Neither is better on its own. A CNC router is the right tool for cupped, twisted and live-edge slabs, and a wide belt sander is faster and smoother on flat panels. Both are followed by sanding through the grits before the finish goes on.
Does SlabHome check production?
No. SlabHome matches your request with up to 3 workshops and introduces you. Production, photos, samples and approval are agreed between you and the workshop you choose, which is why this page lists the photo to ask for at each stage.
Free for buyers. We reply within 24 business hours. How matching works: what we do and do not do.