How to store planed and sawn timber to prevent warping

How to store planed and sawn timber to prevent warping

Sawn and planed timber will almost always come kiln dried which means the majority of the excess moisture has been removed from the timber, therefore is less likely to experience warping, splitting or damage once It has been cut. However, you must remember that timber is a natural product and has to be stored correctly to avoid any damage.

This article provides hints and tips on how to store your timber before you start a project to make sure it maintains its perfect finish, and after you complete your project I you have an left over timber planks, for future use.

What is Warping?

When a piece of timber becomes bent or slightly curved it is classed as being warped, meaning the timber board is not longer straight and will not fit flush on top of a flat surface.

Warping is cased by an imbalance in the moisture content in the timber, if sored incorrectly timber can absorb moisture in different parts of the grain, causing warping to occur.

Moisture content in wood explained:

The moisture content level within timber dictates the potential movement and possible distortion in its final application. The moisture content of wood depends on the relative humidity and temperature of the air surrounding it.

The following video explains moisture content in wood in more details:

Further reading: Moisture content in wood

The different classifications of Timber Warping

Its widely agreed that there are five different classifications of timber warping, they are as follows:

Twist or Wind Warping:
The timber effectively twists at both ends of the timber board I opposite directions, this results in a piece of timber that looks like a twisted ribbon

Kink Warping:
A kink warp is when a timber board bends or bows up at one end of the board.

Cup Warp:
A cup warp is where the edges of the timber board roll or curve towards the centre of the board.

Bow Warp
Similar to a kink warp, but for a bow warp the timber board bows or bends upwards on both ends of the timber boards

Crook Warp:
A crook warp is often caused when one edge of the timber board has been exposed to a different level of moisture, warping the board to look like the letter 'C'.

Remove all packaging from your timber as soon as you can

When your timber is delivered it is essential to remove all the external packaging as soon as you can.

All good timber suppliers will ensure you wood is delivered safely and securely, normally this means lots of packaging. Whilst this is good for secure delivery, if left on it can cause the timber to sweat, causing an increased level of moisture inside. This can create warping and mould build up if left over time.

After investing in quality timber leaving the packaging on could ruin it instantly, so make sure you remove it straight away. Immediately store the timber inside.

As soon as you can make sure you store the timber inside in a controlled temperature. Leaving it outside will expose the timber to variations in heat and moisture, resulting in possible damage to the wood.

Make sure you have a storage area ready in time for delivery, that is clean and dry, and ideally not accessed too often to ensure the air moisture levels remain as consistent as possible. Here are a few storage tips:

  • Ensure the foundations for the storage are flat and level, i.e. flat foundations.
  • Uses Stickers (see below) to uniformly stack the wood boards (ideally groped by thickness, if not the same).
  • Make sure the Stickers are flat and aligned horizontally.
  • Ensure the timber boards have enough surrounding space to maximise ventilation and reduce sweating.
  • If stored in a humid place, try and cover the timber with a membrane that does not retain moisture, to keep the timber dry.
  • Adding weights to the top of the stack can reduce the possibility of cup Warps.

It is important to regularly check the timber once stored, to ensure the moisture levels are kept to an good standard to reduce the possibility of timber warping.

What are 'stickers' used for in timber storage:

Its is recommend you store your timber flat and horizontal. Do not place boards directly on top of each other, instead lay small piece of timber at a 180 degree angle on top of your timbers.

These strips should ideally be around 2.5 centimetre square and all be cut to the same size from the same material. These strips are known as 'Stickers' which should be placed roughly 40-50 cm apart. An example of what a sticker looks like can be seen in the main image for this article. are clearly shown on the main image on this article.

Conclusion, four tips for storing timber:

1. Keep the timber dry.
The first section in this article mentions unwrapping the timber boards as soon as you can. Timber and water don't mix well if you want your timber to remain, smooth, flats and consistent. Most timber will happily absorb water when it can, so unwrap the timber and do your best to keep it dry and not exposed to any form of moisture. Storing timber inside is essential to keeping it dry, avoid storing it outside as much as you can, even if you plan to use it quickly.

2. Keep the timber boards flat
In order to keep your timber boards straight, firstly avoid moisture and secondly store flat and horizontal.

Use stickers to sperate the boards so they are not laying on op of each other and ensure a constant air flow.

Try to avoid staking your timber boards vertically, this will expose the different ends and edges to different temperatures and moistures, which could result in one of the five types of timber warping.

3. Keep the timber indoors
An expansion on point 1, keeping the timber dry. We always recommend keeping your timber indoors as much as you can. If you plan to turn the timber it would be a benefit to store your timber indoors for at least seven days before you start working it to allow the wood to acclimatise.

4. Keep your timber storage organised.
By keeping toe same material and board sizes together, does not only make it easier to find the boards you need, but it also allows the timber to have a consistent moisture exposure.

Mixing different types of timber can increase the changes of different heat an ventilation, possible leading to warping.

In conclusion, its always best to buy the highest quality timber you can, then to loom after it you must store it well, so many people invest in wood then fall at the first stage by not unwrapping the wood.

If you love good quality wood, hopefully this article has helped explain ow to look after and store timber boards correctly.

Published: 04/03/2023

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