Timber is a natural product — and like all natural materials, it moves. Even perfectly kiln-dried, high-quality timber can twist, cup, bow or split if it isn’t stored correctly once it arrives on site.
That’s why proper storage is absolutely essential to keeping your timber straight, stable and ready for the job.

Below is a simple, practical guide to storing timber correctly, whether you’re keeping it for a few days or several months.

Why Timber Moves: A Quick Explanation

Timber constantly absorbs and releases moisture depending on its surroundings.
This means:

• Too much moisture → boards can swell, cup or warp

• Too much heat or sunlight → boards can dry unevenly and twist

• Uneven support → gravity will bend longer lengths over time

Even the best-quality timber cannot avoid natural movement — but good storage can massively reduce it.

1. Store Timber Flat and Fully Supported

This is the number one rule.

Timber should always be stored flat, on level ground, and supported across the full length.

✔ Correct method

Use bearers (spacers) placed evenly underneath the stack:

• Bearer every 400–600mm for smaller sections

• Bearer every 600–800mm for larger, heavier sections

• All bearers must line up vertically to avoid creating pressure points

✘ Avoid

• Leaning timber against walls

• Leaving long lengths unsupported in the middle

• Stacking timber on uneven ground

Poor support is the biggest cause of bowing.

2. Keep Timber off the Ground

Never store timber directly on soil, concrete or gravel.
Moisture will rise straight into the boards.

What to use instead:

• Timber bearers

• Pallets

• Bricks or blocks

• Dry timbers laid crosswise under the stack

Keeping good airflow underneath prevents moisture absorption and mould.

3. Protect Timber From Rain & Moisture

Timber should not be left exposed to the weather.

✔ Best practice

Cover the timber with:

• A breathable tarp

• Roofing membrane

• Timber sheet with airflow gaps

✘ Avoid

• Wrapping timber in an airtight plastic sheet (causes sweating and mould)

• Leaving timber uncovered outdoors

• Allowing water to pool on the top of the stack

If timber gets soaked and then dries too quickly, twisting and checking are almost guaranteed.

4. Avoid Direct Sunlight

The sun dries timber unevenly.
One face heats up, the other stays cool → the board twists.

Store timber:

• In the shade

• Indoors

• Under a canopy

• Under a sheet with airflow beneath it

If storing outside, make sure sunlight cannot directly hit the boards.

5. Allow Airflow Around the Stack

Timber needs to breathe.

Use stickers (thin strips of timber) between layers if storing for more than a week:

• Stickers must align vertically with the bearers

• One sticker every 400–600mm

• This prevents trapped moisture and mould growth

This technique keeps timber straight during longer storage periods.

6. Secure the Stack

Long lengths can shift if knocked.

Use:

• Banding straps

• Ratchet straps

• Bricks or blocks at the sides

Do not overtighten straps — this can distort thinner boards.

7. Store Indoors When Possible

The best place to store timber is:

• A garage

• A dry shed

• A workshop

• A covered outbuilding

These environments maintain more even temperature and humidity.

If this isn’t possible, outdoor storage can work — as long as the timber is:

• Off the ground

• Fully supported

• Covered

• Shaded

• Ventilated

8. Avoid Common Timber Storage Mistakes

These are the errors we see most often:

❌ Storing timber standing upright

Encourages twist and bow.

❌ Keeping timber in sealed plastic

Creates condensation and mould.

❌ Leaving freshly delivered timber in the sun

Leads to cupping and splitting.

❌ Not supporting the full length

Mid-span sag causes permanent bend.

❌ Throwing timber in a shed with no airflow

Traps moisture and leads to mould.

9. How Long Can Timber Be Stored?

It depends on conditions.

Indoors

Months or years if well supported and ventilated.

Outdoors (covered & supported)

Weeks to months, depending on weather.

Outdoors (uncovered)

Not recommended — twist or moisture damage may occur within a few days.

10. Let Timber Acclimatise Before Use

For interior projects (flooring, skirting, joinery), timber should be allowed to adjust to the room conditions.

Recommended acclimatisation:

• 48–72 hours before installation

• Lay boards flat

• Keep them in the room where they will be fitted

This helps reduce movement after installation.

Need Help Choosing the Right Timber?

If you want advice on storing or selecting timber, call our team on:

? 01656 745959

We’re here to help with anything from garden projects to structural timber orders.