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Shed treatments offer increased protection against mould, rot, and insect infestations. As amazing as that may sound, this weather defence decreases over time.
The good thing about these wood preservatives, though, is that they can be reapplied as needed. A good quality paint brush, other than the treatment itself, is all you need. But the million-dollar question remains: how do you treat a garden shed?
Different Types of Shed Treatment
Garden shed treatments come in different varieties and finishes. Two common options are preservers and exterior oils.
Preservers
Shed preservers are available in solvent-based and water-based formulas. Although both use similar ingredients, there are a couple of differences in how they work.
A solvent-based preserver contains around 75% white spirit. This gives it a stronger smell and a longer drying time of two to six hours. Recoating usually needs to wait until the next day.
A water-based alternative contains roughly 10% white spirit, making it more eco-friendly. Apply it on a dry, moderate day. It dries within an hour and can be recoated shortly after.
Exterior oils
Wood oils can be used on top of most preserver to add a waterproof finish. They enhance timber’s natural colour and help prevent cracking, splitting, and warping.
Depending on the preserver you’ve used, wait 24 to 48 hours before applying oil. Clear and coloured options are available, and a yearly top-up keeps the finish fresh.
A few things to consider
If you’re unsure which to choose, you can use both to get that more complete level of protection.
Check what type of cladding your shed has. Overlap sheds absorb treatments more readily, so spray-on preservatives can help. Tongue and groove cladding is denser, so a brush or roller works better.
The shed base is just as important as the walls. Even treated timber can rot if the unit sits on damp ground or water collects underneath. A well-drained, level foundation is a must – or go for a pressure-treated timber base. This helps extend the life of your shed and keep the treatment effective.
If you plan to paint your shed with a product that doesn’t already contain a preserver, treat it beforehand. Go for a wax- and silicone-free type. Paints with added preservatives don’t need an extra preserver underneath.
Application and Shed Treatment Process
Here’s a step-by-step guide on how to treat your garden shed:
1. Prep the shed
If your shed is made from untreated timber, treat it as soon as possible.
For older sheds, clean the exterior thoroughly and remove algae, fungi, or moss. Check for gaps and fill them with caulk. If you used a silicone-based filler, allow it to dry for about a day.
Panels that were stained, painted, or varnished need to be stripped back to bare wood. Sand from the top down so dust doesn’t land on prepped surfaces. Cover windows and trims with masking tape, and lay down dust sheets to catch any splashes.
2. Apply your wood preserver
Use a mix of wide, angled, and roller brushes for corners and large areas. Apply the preserver across the entire exterior. Two to three coats are ideal, with each layer left to fully dry based on the product instructions.
Note: Treating the interior isn’t usually necessary. It’s only helpful if you store plants or anything that creates moisture inside. Annual application of the inside would require you to empty everything out of the shed every time.
3. Add exterior oil
Once the preserver has dried (usually after a day or two), apply the oil. This adds extra water resistance and helps maintain the timber.
4. Paint it
If you plan to paint the shed, wait for dry weather and temperatures above 5°C. Use a roller for broad areas and a smaller brush for trims. Specialist shed paints offer durable coverage and UV protection.
Where Can I Buy Shed Treatment?
You can get it from us! Choose from:
- Protek Royal Exterior Superior Finish 1L. It’s a high-quality finish with a soft lustre that lets the wood grain show through. Water-repellent, low odour, child-safe, and quick drying.
- Protek Wood Stain and Protector 5L. A versatile, weatherproof wood paint with long-lasting protection. Easy to apply, fast drying, and pet and plant friendly.
A 5-litre tub will suffice for a standard 8×6 shed. But if your outbuilding is larger, you may need more to achieve an even spread.
For more details on paint quantities, read: How Many Litres You Need to Paint Your Garden Shed
Waterproofing and Maintaining Your Shed
Beyond treatment, you can add more protection by improving waterproofing. Insulate walls to prevent moisture build-up with bubble wrap and fibreglass wool. Breathable membranes are also great, but they tend to cost more than the two. You can also waterproof the roof using shed felt. This takes more time but gives reliable coverage.
Check regularly for loose panels, holes, or worn areas. Keep hinges lubricated and window frames protected. Clear gutters and check the felt for tears. Trim back nearby plants and branches to improve airflow and prevent roof damage.
Ventilation matters, too. Damp items like bikes can hold moisture, so airing out the shed reduces the risk of mould. Otherwise, the inside can get way too hot, which isn’t good.
[What Happens When a Wooden Shed Gets Hot Button]
Round-up
A brand-new garden shed looks superb, even better when it’s pressure treated. Either way, it’s still exposed to storms, heatwaves, and harsh snow. These elements can cause wood damage, leading to cracks and ageing. This is where shed treatments come in.
Before installing a shed, it’s worth checking whether it affects your property taxes. In the UK, most small garden sheds won’t change your council tax. But if yours is on the bigger side and used as a living space, it could have an impact.
