How to prevent your shed from succumbing to wood rot this winter, according to experts

It's easy to forget your shed in the winter months, but you need to do a few things before the worst weather arrives to keep wood rot at bay.

Several winter gardening mistakes can trip you up, but completely abandoning your wooden garden structure during the wet season is pretty high on the list. Whether you use your shed to store your best garden furniture or all your essential gardening tools, it's an outdoor building that requires maintenance.

And while they're not typically used as much during winter, this is when they take the most battering from the weather. With that in mind, experts share tips to ensure your shed and other wooden outdoor buildings don't suffer from rot and moisture damage.

How to prevent wood rot in your shed: 4 expert tips

If you've been decluttering your shed ahead of the colder months, you may have already noticed a moisture issue or the first signs of rot.

That doesn't mean your shed is destined for the tip, but it does mean you need to act quickly to stop any further rot and prevent it from happening in the future.

1. Keep it ventilated

Just as you'd protect the rest of your garden from heavy rain, your shed needs help with wet weather too.

“Good airflow is important. Try to avoid placing your shed too close to fences, hedges or overgrown plants, as this can restrict ventilation and prevent the timber from drying out properly after wet weather," explains James Crane, director at Crane Garden Buildings. "If you have climbing plants growing against your shed, keep these trimmed back too."

If your shed has windows, it can be helpful to open them once in a while during winter and let some air into the space. Only avoid this when it's raining or when the frosts arrive.

2. Treat with a wood preserver

If you've ever had to remove algae from fence panels or your shed, you'll be aware of how helpful proper wood preservers are in keeping the material in good shape.

“Don't underestimate the importance of regular timber maintenance. Depending on the type of timber and finish, applying a suitable protective treatment at the recommended intervals can help prevent moisture from penetrating the wood," explains James.

"A well-made timber shed that's properly installed and looked after should provide many years of use, even through the wettest British winters,” he continues.

3. Check the roof

While you're out sorting the garden out this autumn and winter, make sure you check your shed roof. “One of the most important things is to keep moisture away from the timber. Start by checking your shed's roof for any damaged felt, loose shingles or gaps that could allow rainwater to seep in," says James.

"It's also worth clearing away fallen leaves and debris from around the building, particularly where they collect against the walls or around the base, as these can trap moisture against the wood," James points out.

Continuing to check the roof as the season progresses will help you avoid any particularly bad damage to your shed from both wind and rain.

4. Reduce the moisture inside

As the winter weather arrives, you'll no doubt be looking for ways to reduce humidity in your home. The same should go for your outdoor buildings, and luckily the same solutions work.

As well as ensuring adequate ventilation, you can find one of the best dehumidifiers for bathrooms because it doesn't need to be plugged in. Having one or two, depending on the size of your shed, in the space can make a huge difference to the moisture levels.

Reducing moisture in the shed will drastically slow down any rot growth or the possibility of mould, which is especially important if you use the space to store soft furnishings.

FAQs

What to put under a shed to stop rotting?

Before you've even installed your garden shed, ensuring you've chosen the right foundation is a huge help in preventing wood rot.

"You want a firm, level base that drains and keeps the timber off the ground, so a concrete slab over a polythene damp-proof membrane or paving slabs on a compacted sub-base would work," says Andrea Haydon, a home improvement and DIY expert and Director at Simply Plastics. "Recycled plastic grid bases filled with gravel can also do the job, and they’re particularly good for softer ground because water drains straight through them."

"The shed should sit on pressure-treated bearers rated for ground contact, which is Use Class 4 under the Wood Protection Association’s system, as standard Use Class 3 ‘outdoor’ timber isn’t designed for it," he adds.

"If you cut a bearer, brush preservative onto the fresh end, because the treatment doesn’t go all the way through the wood. Also, make the base slightly smaller than the shed’s footprint, so rain running off the walls drips onto the ground instead of pooling on the base and soaking into the floor edges," Andrew explains.

Can you stop wood rot once it starts?

Finding wood rot is far from ideal, especially this time of year when the weather is only going to get worse. Luckily, there are some things you can do to fix the issue.

"If you catch it early, yes, one reliable test everyone can do is with a screwdriver. Simply push it into any suspect areas, and if it sinks in easily or the wood seems spongy, it means you’ve got rot. From here, you first need to fix the water source, and then let the wood dry out. Using a moisture meter, get the timber below 16% to 18% moisture, so you prevent further decay," says Andrew.

"Next, find and cut the soft wood back to solid timber and treat the surrounding area with preservative before filling any small holes with wood hardener and exterior filler. If the rot has reached a bearer, floor joist or corner post, replace that piece entirely, as patching structural timber only buys you time before it will inevitably collapse," he continues.

Make sure you're regularly checking on your shed during the autumn and winter months, as catching it early could save you a lot of money in the long run.

Before winter sets in, take note of household items you should never store in a shed and therefore need to be stored elsewhere.