Most timber buildings, including log cabins and summerhouses, arrive untreated. A good choice of paint creates a garden building that looks great and remains protected from the elements.
For most of us, our summerhouse or log cabin will arrive built from untreated timber which is yet to be exposed to the great British outdoors. As a blank canvas, we are free to decorate the building to suit our taste and match the colour scheme of the surrounding garden. Leading to some very cool cabins with everything from bright summer beach bar themes to modern and contemporary grey designs.
Painting the exterior doesn’t just add colour to your garden building. It plays a vital role in maintaining protection from the elements and keeping a watertight seal throughout the year. Without adequate protection, a garden room will decay over time. I’m sure we have all seen old grey sheds which have been left to rot in a garden, and this ageing is exactly what we want to avoid.
A log cabin or summerhouse is usable throughout the year with the appropriate heating and insulation. Winter is not the kindest time of year for garden rooms and will be when lack of protection begins to show in the form of mould, fading colour and rot.
Luckily, choosing the right products to protect your investment is easy. Getting it correct in the beginning will reduce the maintenance required in the future. In this post, we will detail our three-step approach to achieving optimum protection for a timber garden building.
Table of Contents
Before you start
Taking time to prepare the summerhouse or log cabin before treatment will ensure everything going smoothly.

How long to wait before painting
When a garden building is first installed, there is no protection and the wood is completely exposed to any harsh weather conditions. Leaving too long before treatment may allow moisture to start creeping in. Wood is naturally porous and will soak up moisture in the atmosphere and its surroundings. Timber expands slightly when it takes on water, over time leading to slight movement in the boards or logs which make up the structure.
We recommend treating your new garden building as soon as possible. At the absolute latest, it should not be longer than two months. This will provide immediate protection and the best performance for paints on fresh wood.
It can take several days to finish painting and this should be taken into account when planning the most suitable time. Before applying the next product, it is recommended to let each dry and harden for 24 hours. Even getting the first product on and waiting to start the second is going to provide some protection.
The best weather conditions for painting
With the excitement of receiving a new garden building, it can be easy to rush out right away and start painting. The ideal time is in the spring onwards when temperatures are sufficient and the weather is dry.
Painting can be affected when temperatures are in single digits. A longer time to dry is required and some pealing may occur where it struggles to take to the wood properly. A mild temperature allows for paint to dry completely before applying a further coating the day after.
A garden building should also not be painted straight after it has rained. The exterior wood may have taken on moisture which will need to dry out again before painting to avoid the vapour being trapped inside the wood.
Start with a clean building
The summerhouse or log cabin should be clean before starting to paint. If it has rained recently, mud may have splashed up around the bottom of the building and dry out on the wood. Painting when not fully cleaned will result in bits of paint flaking off where they have gone over mud and other dirt.
If the building has been painted before, the existing coating should be weathered sufficiently and not allow water to bead on the surface. An existing coating could make it difficult to paint as the new product will not be able to soak adequately into the wood.
Cover the surrounding area
Splashes from paint tend to get everywhere, including places you don’t want them. Be sure to remove any objects around the building and allow enough space to work. Dust sheets are great for covering surrounding patios and decking. Edges and parts which are not being painted should be covered with masking tape to provide a clean finish.

Solvent vs water-based coatings
Both water-based and solvent-based wood preserver and paint products are available for treating garden buildings. Solvent-based products soak deeper into the wood, offering very long-lasting protection. Unfortunately, they are not the easiest products to work with. Long drying times and strong fumes have seen a decline in their use in recent years.
Water-based products are generally the preferred choice now thanks to better advancements in chemical technology. They contain less VOCs and dry faster. These days, whether solvent or water-based, a high-quality product is going to provide significant levels of protection. Inside wood preserver, for example, it’s the other ingredients that provide the anti-fungal protection, not the base of the product.
Paint vs wood stain
A wood stain creates a translucent and rich finish. The lower opacity allows the natural grain and pattern of the wood to show through. A natural finish is achieved with wood stain, whilst still allowing the colour of the wood to be changed. A stain is often easy to apply and looks great even after the first coat.
A wood paint provides a complete block of the natural wood underneath and looks great as a refined and clean look. If you don’t want to see the natural pattern of the wood, paint is the choice to go for. The choice of paints is also much wider, with an unlimited amount of colours to choose from.
We love the look of both, with a stain on the walls and paint used to highlight features including the side of roofs and doors.
1) Wood treatment & basecoat
A pre-treatment is essential to provide long term protection to the structure of a garden building. A wood preserver is designed to provide protection against rot, mould and insect attack. The anti-fungal treatment stops growth from damp and protects the wood from breaking down or anything getting in overtime.
A wood preserver is designed for use as a basecoat and does not provide any sort of water protection. Paint or wood stain can still easily be applied on top and soak into the wood. This treatment is clear and can be difficult to see when applying. Be sure to provide good coverage to the end grains and parts exposed to the ground.

We used Cuprinol clear wood preserver which has lots of good reviews and proved easy to apply. Some wood preservers also contain waterproofing as they are designed as the only coating to be used. These are not suitable for using paint or stain products on top and should be avoided if planning to use any other product as well.
2) Applying paint or wood stain
Once the base coat of anti-fungal treatment has been applied, it’s now time to apply our wood paint or stain. Importantly, a clear stain should not be used here as it does not provide any UV protection. As timber is exposed to the suns UV, over time it will lose the natural colour and fade to a dull grey appearance. Colour pigments in a wood stain or paint are required to provide protection from the sun.
We recommend choosing a high-quality product here which is going to provide long-lasting weather protection and minimal maintenance in years to come. Low-cost fence paints should be avoided as they will not provide the performance required. To achieve the natural colour of the wood, a stain should be used which matches the wood of the cladding on your garden building. We used OSMO Wood Stain which provides good quality UV protection and excellent water resistance. The tin will need mixing before use as the pigments sink to the bottom when it is left sitting over time.

For paint, a high-quality brand such as Dulux Trade, Protek or Sadolin will offer the best protection for your investment. Each side of the building at a time should be painted from the top down.
3) Finish with a clear topcoat
A clear coat on top is not necessarily required, but we chose to add one as we already had the product and wanted to provide an extra layer of protection. We originally purchased the clear paint to paint our summerhouse and keep the natural look. After realising there would be no UV protection we changed to the coloured stain and so applied a clear coating on top.
The idea of the topcoat is to provide an additional layer of weather protection and enhance the look of the garden building for a longer period. As the paint wears over the next few years, it is the clear topcoat rather than the coloured stain, reducing the loss of the colour over time. The aim is that this will reduce any later coats required.
The clear coating also provides a really nice and rich glossy effect to the summerhouse. The building always looks as if it has been painted recently. We used the clear version of Protek Royal Exterior. While expensive, the finish is long-lasting and durable.
Maintenance
Regular maintenance is important to ensure your summerhouse or log cabin has not been damaged by the weather over time. Inspecting the paint-work once a year over the summer is enough to see how well it is ageing. If water still beads from the paintwork, it is fine for another year.

If water no longer beads when sprayed against paintwork, a fresh coat is required to maintain protection. With a new garden building, the initial coat should be expected to last at least 3 years before any maintenance is required.
Summary
Overall, painting is an important decision for any summerhouse or log cabin. As well as adding colour to your garden, the paintwork provides a vital role in keeping the building protected long-term.
The sooner a garden room is painted, the better. Ideally, painting should take place when weather conditions allow for dry and mild temperatures.
Our three-step approach aims to provide sufficient protection for years to come.
Leave a Reply