Guide
Where to cut when you have no workshop: a sheet of board in a flat
Every guide about tools assumes you have somewhere to use them. Most of the people building a Kamba unit do not have a workshop: they have a flat in Luxembourg, Paris or Berlin, and their first question is not which saw to buy but where to put a sheet of board down to cut it. The short version: a plunge saw running on a guide rail, over a sacrificial board on the floor, is what replaces the bench, the table saw and the workshop. Everything else follows from that.
The workshop nobody has
A cabinet shop cuts sheet material on a panel saw or a table saw: the machine stays still and the board moves through it. That needs a room the size of two sheets and a floor that can take the machine. Nothing on a Kamba plan requires it.
With a rail, the logic flips. The board stays still, on the floor if that is where there is room, and the saw moves along the rail. The cut is guided, so it comes out as straight as the rail; the depth is set, so the blade stops a few millimetres under the board and never reaches the floor. The rail is what turns a living room into somewhere a panel can be cut.
This is also why the usual advice, cut on trestles rather than on the floor, is advice about a freehand circular saw or a jigsaw. There, raising the work is what lets the offcut fall free and keeps the blade from pinching. With a rail on a sacrificial board, the whole panel is supported everywhere, nothing sags and nothing pinches, and low is the safer place to be. Our tools guide says so too.
Four real situations, and what each one allows
There is no right place, only the way of working that goes with the place you have. Four situations cover almost everyone.
| Where you are | Cutting | Assembly and finishing | What to plan for |
|---|---|---|---|
| A living room with a table | Full sheets on a sacrificial board on the floor, one cut at a time; the small pieces on the table. | The table, protected, is where the carcass goes together. Paint and varnish want the window open or a balcony. | Dust sheets under everything, a vacuum on the saw, and the cuts in daylight hours for the neighbours. |
| A balcony or a terrace | The best place to cut: the dust stays outside and the noise is brief. Check that the sheet goes through the door. | Assembly back inside, on the floor or the table. Finishing outside on a dry day. | Wind takes dust sheets and sawdust; weigh the edges down. Store the boards flat indoors between sessions or they will cup. |
| A shared cellar or garage | Room for a sheet, often the only room. Cut there, carry the pieces up. | Assembly where the finished unit will stand, so nothing large has to fit through the stairwell. | Light: bring a lamp. Damp: do not store board there for long. Ask before you leave dust behind. |
| A garage or basement of your own | Cut, assemble and finish in one place, with the boards stored flat nearby. | Everything, including the messy steps. | This is the closest thing to a workshop, and it still wants extraction and a window or a door open. |
The order of work matters more than the space. Cut first, wherever the sheet fits, then carry pieces a tenth of the size to wherever you will build. A plan that arrives as a cut list is a plan that already lets you work this way.
How much floor a cut needs
Three things set it: the size of the sheet, how far the rail has to run past the sheet at each end, and room for you to move along the cut. Nobody gives this figure because it depends on the sheet you buy, so derive it for yours.
The sheet comes first. It is not a standard: it changes with the country and with the material. In France, the MDF sheet Kamba sizes a plan against measures 280 by 207 cm at a trade supplier, and a DIY store more often sells 250 by 122 cm. The builder asks which country you buy in and checks every panel of your plan against the format sold there, so no piece on your cut list is longer than the sheet you can bring home.
Then the rail. The saw must sit fully on the rail before the blade enters the board and still be on it when the blade leaves, so the rail has to run past the cut at each end by at least the length of the saw's base plate. Measure yours; the manufacturers' own guidance comes to about 20 cm at each end.
Add it up for the DIY-store sheet cut along its length: the sheet, the overhang at both ends, and you need a rail and a strip of floor about 3 m long, plus a walkway on the side you push the saw from. Cut the sheet across instead and the same rule gives a little over a metre and a half. A rail of that length is the one purchase this setup needs; two shorter rails joined with a connector do the same job.
The sheet formats on this page are the ones Kamba's registry records for France, for the same 18 mm board the other guides derive their figures from. The format that counts is the one your merchant sells, and the builder checks your plan against the country you choose.
The setup that replaces the bench
Lay a sheet of rigid foam insulation on the floor, larger than the panel if you can, and put the board on it. The foam is sacrificial: the blade scores it a few millimetres deep on every cut and it lasts for years. Two dust sheets under it protect the floor from the foam crumbs; the panel is supported on its whole face, so nothing sags.
Set the depth of cut to the board plus about 5 mm, one tooth of the blade showing under it, and no more. That is enough to go through cleanly and not enough to reach the floor. On a plunge saw the depth stop is a lever or a knob on the side; the manual for your saw is the authority on how to set and lock it.
Mark the cut on the panel, set the rail on the line with its splinter guard on the piece you keep, and clamp it at both ends. Two clamps that fit the rail's channel are worth more than any other accessory: an unclamped rail walks on MDF dust. Then kneel beside the rail, on the side away from the offcut, and push the saw the full length in one pass.
Two things to keep in mind: a plunge saw can kick back if it is plunged with the blade already turning against the board, or if the offcut pinches the blade, and it is loud. Plunge before the board, not into it, with the saw stationary on the rail, and let the offcut stay supported on the foam rather than fall. Both guards on the saw, always.
If you do not have a plunge saw, a circular saw with a clamped straightedge on the same sacrificial board makes the same cut, with more care about the offset between the shoe and the blade. Our guide on following a cut line covers that setup.
How to cut a long line straight, and which face goes up
What you can have cut for you
Most DIY stores cut sheet material at a cutting service: you arrive with the cut list, you leave with pieces. For a Kamba plan this is a real option, because nearly everything on the list is a straight cut in a rectangle. It changes what you need at home from a place to cut to a place to build.
It buys pieces, not a guarantee. The saw is theirs and so is its tolerance; ask what they commit to, and check the first pieces with your own tape before you leave. Ask how they charge, per cut or per sheet, before the cutting starts. A vertical panel saw cuts square and straight, but the operator cuts what is written, so the list must be the plan's, with the grain direction and the count of each piece.
And what it does not include: the angled pieces of a sloping-ceiling unit, whether cut to a marked line or with a tilted blade, are not part of a store service. Neither, usually, is anything below a minimum size. Those pieces you still cut at home, but they are short pieces, on the table, not a full sheet.
The store also keeps your offcuts unless you ask. Ask: a strip with a factory edge is the straightedge for your next cut.
Dust and noise when you have neighbours
Cutting and sanding MDF makes a fine dust that goes everywhere and stays in the air. Wood dust of any kind is classed as a cause of cancer in humans; that is the reason for the mask and the extractor. A plunge saw has a port for a vacuum: connect it, on every cut. Wear a rated FFP2 mask for cutting and sanding, open the window, and vacuum rather than sweep.
A plunge saw is loud enough to damage hearing over time, and loud enough for the building to hear. Ear protection for you; daylight hours and a word to the neighbours for them. Group the cuts: with the list in hand, all the cutting for a unit fits in one session, and the rest of the build is quiet.
A balcony or a terrace is the answer to both, when you have one. The dust stays out and the noise is brief. Bring the pieces in as they are cut, so nothing is left outside overnight.
In Kamba
The plan you print is written for this way of working. It gives a cut list with every piece at its final dimensions, the total number of pieces, and the board area they add up to, so you know what to buy and what to cut before you have moved a single sheet.
Every panel on that list was checked, when you designed the unit, against the sheet format sold in the country you named. A plan that would need a piece longer than that sheet is refused in the builder, not discovered at the store.
What the plan does not do is lay the pieces out on the sheets for you or count the sheets. The longest piece on the list is the one that sets the rail you need; the rest is the arithmetic on this page, with your merchant's sheet in it.
Read the full guide: how to build custom shelving
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