What’s the difference between sawn and planed timber?
Sawmills will traditionally plank timber by sawing pieces in a variety of thicknesses from the log and this will give you a sawn finish. Sawn timber is rough in texture, with splinters and you may get inconsistencies in how flat and regular the boards are. Planed all round (PAR) or planed square edged (PSE) is the process where a sawn board is then planed down to a smooth, regular and square edged piece. Sawn boards are usually sold to people who have the means to plane or machine themselves whereas PAR would give you a finished size to start building with.
Appearance
Sawn boards are rough in texture and this can result in the timber having a darker and dull colour. The planing process brings out the natural heart of the tree and you see more of the grain pattern where it is smooth. It is a lot easier to see what colour and character the timber will have when it is consistently planed all round. Boards will also have a more parallel even look on all sides where the sawn board could have tapered angles and scars or saw marks on the faces.
Planed all round timber is the best way to appreciate the timbers natural colour and grain pattern. The smooth consistency will allow you to achieve better results when oiling, staining or painting.
Planing tolerances
All mills or joinery workshops have their own tolerances but a good universal ruling would be to allow 3mm top and 3mm bottom to be cut off in the thickness when you plane all round which is 6mm overall. For example a board that was 26mm as a sawn thickness would be planed down to 20mm thick when its finished.
Sawn boards can be very irregular and inconsistent as they are crudely sawn with heavy duty blades from the log. Therefore its always a good rule to allow for 10mm when planing in the width to take out the irregularities and avoid inconsistencies in finish.
Parallel & straight
Planing timber is not just about making it smooth. One of the key benefits in planing a sawn board is to ensure you get the board parallel and regular. This is essential for building with as it will allow you to strike a true line off each of your timber pieces and avoid tapered gaps and your construction being out of square.
A great way to ensure your timber is cut perfectly to your sizes is to ask for your timber merchant to plane it all round in their mill. You can ask Timbersource for bespoke sizes and they will advise on the most economical way to achieve.
Machining challenges
Machining can come with its challenges. With wood being a natural product it can have a few quirks. Splits, shakes, knots and tension can all lead to unexpected results when machining solid timbers. This can be a risk for those that like to buy their timber sawn. A perfectly good board can bend with tension release when you cut through certain grain patterns, knots can fall out leaving holes and splits can develop.
If you want Timbersource to take the risks machining and do all the heavy lifting, we can cut and plane your timber for you. If we experience any quality issues with our timber while we are machining it we can get another piece from stock. If the customer machines a piece and it has an unexpected result they may need to fork out for a new one.
How do I buy planed timber?
Buying planed timber has never been easier. You can simply choose the type of wood you like the look of or by researching it’s practical benefits. Then you need to choose the thickness you want, followed by the width, length and the quantity of pieces. Then you need to choose PAR as your finish option. When you have this delivered it will come in these exact sizes, smooth and consistent from one end of the piece to the other.
You may need to sand this a little with a medium or fine sandpaper just to get it totally smooth because some timbers are more course in their grain than others but generally this should be ready to start building with. To buy planed timber go to the cutting list on the homepage and start experimenting with instant timber prices now!
