How to treat wood before winter: fence, terrace and gazebo in 6 steps

The weather affects the result as much as the paint itself. Stain manufacturers state a minimum of +5 °C for the air, the painted wood and the material itself. Some products require up to +10 °C. The optimum is 15–25 °C and a relative humidity of 40–80%.

In the Czech Republic, these conditions are reliably present in September and October. In November, it is already freezing in the morning, fog lingers during the day, and the wood does not have time to dry. Painting wood in autumn has one advantage over summer: the sun is not scorching, so the glaze does not dry out too quickly and is absorbed better.

When preparing the garden for winter, most people think of leaves, hedges and a final cut of grass. Wooden structures are often missing from this list. Extending the life of wooden structures depends primarily on the condition in which they enter the winter.

Wood is ready for painting if its moisture content does not exceed 15% for coniferous wood and 12% for deciduous wood. The most reliable way to check this is with a needle moisture meter, which you insert into the wood in several places. Without a device, the rule of thumb is: wait at least 2-3 dry days after rain and paint only after the morning dew has disappeared.

Measure especially where water stays the longest: on the bottom boards of the fence, where it meets the grass, at the edges of the boards and under flower pots on the patio. If the moisture meter shows more than the paint manufacturer allows, wait, even if the top surface looks dry.

Freshly cut wood contains about half the water content. Therefore, do not paint a new fence or gazebo made of damp lumber immediately after assembly. We also describe why wood needs air and time to dry in our article on how to build a shed in which wood dries .

Even the best paint won't last if you apply it over dust, algae, or loose old paint. Preparation takes more time than the actual painting. But it's the preparation that makes the difference between one winter and several seasons.

Wash the patio and fence

First, remove moss, green algae and dried dirt. For larger areas, a high-pressure cleaner will save you hours of scrubbing. On wood, however, work with lower pressure, a flat nozzle and from a distance of more than 30 cm, always in the direction of the grain. Too strong a jet at close range will cause the wood to become fibrous and the surface will be hairy.

Tip: Before you start cleaning the entire patio, test the pressure and distance in a small, less visible area (e.g. in a corner).

After washing, let the wood dry thoroughly. Check the moisture content again before proceeding, as washed boards will absorb more water than you might expect.

Old stain that is holding can be cleaned and sanded down. Cracked or peeling paint must be removed completely, otherwise the new layer will fall off with the old.

A common question is how to paint varnished wood. Varnish creates a sealed film on the surface, into which neither the glaze nor the oil can soak. If the varnish is intact, sand it to a matte finish and use a paint of the same type. If it is cracked, remove it completely. For straight fence or railing boards , a belt sander with a belt width of 100 mm is suitable, which will quickly remove both old paint and varnish.

Sanding of wooden fence and terrace

Sand smooth wood in the direction of the grain with 80-120 grit sandpaper. This will open the pores and help the paint adhere better. When sanding a wooden fence with a large number of battens, you will appreciate a lightweight orbital sander that can reach edges and corners. You can find an overview of types in the sanders for rent category.

Sanding creates fine dust that irritates the eyes and respiratory tract. Wear a respirator and safety glasses, and with a belt sander with a noise level of 82 dB, also ear protection. Always connect the sander to a dust extraction or industrial vacuum cleaner, otherwise the dust will be trapped in the new paint.

If you're wondering what wood stain is: it's a semi-transparent coating that partially soaks into the wood, preserving its structure and protecting it from water and UV rays. Oil penetrates deeper and doesn't form a film on the surface. Topcoat completely covers the wood and creates an impermeable layer.

When deciding how to treat your wood, the table will help you choose based on what you are painting and how often you want to repaint.

The comparison shows a simple rule. Oil belongs on the terrace you walk on, because it doesn't peel off and you don't have to sand down to clean wood when renovating. Stain will protect the fence and gazebo. If the wood is already visually worn, a top coat will hide stains and uneven graying.

Apply a wood preservative to new, untreated wood before applying the stain. The preservative for your wooden fence and decking protects the wood from the inside against fungi, mold, and wood-destroying insects, while the top coat protects it from the outside.

If the surface is dry, clean and sanded, you can finish painting in one to two days. It is important to follow the order of the steps and allow enough time for each layer.

1. Choose at least two days without rain with a temperature above the limit specified by the manufacturer.
2. Cover the paving, plants and metal elements.
3. Soak new wood with impregnation agent and let it dry.
4. Apply the first layer with a brush in the direction of the fibers, first on the fronts and edges of the boards.
5. Follow the drying time according to the instructions; for glazes, it is usually 6–24 hours.
6. If the fibers have lifted, sand the surface with fine sandpaper with a grit of 240–280.
7. Apply a second layer, and a third on exposed areas.

Manufacturers recommend 2-3 coats of stain for exteriors. Apply the oil in thin layers and wipe off any excess that doesn't soak in with a cloth after a while. Apply from late morning to early afternoon so the paint dries before the evening dew falls.

The gray color of wood does not mean that it is rotten. UV radiation breaks down lignin, the substance that holds the fibers together, and rain gradually washes it away. This leaves a thin gray layer on the surface that no paint will last long on.

Grayed wood

If you are considering how to treat wood that has already turned gray, start by removing the gray layer. Sand down to healthy, light wood. For larger areas, a de-graying agent, a special cleaning agent for grayed wood, will also help, which you can then wash off with water. Only then proceed with impregnation and painting.

Restoration of a wooden terrace with cracks

Fine hairline cracks in the direction of the grain are common in outdoor wood and will be sealed with paint. Check for deeper cracks with a knife: if the wood softens and crumbles, it is rotting and the board needs to be replaced. Tighten any loose screws or water will be trapped in the holes.

Imagine a cottage with a 20 m² spruce terrace that has not been painted for several years. On Saturday morning, you wash it with a high-pressure cleaner and let it dry. On Sunday, you sand off the gray layer and replace two rotten boards. Two days later, when the wood is dry, you apply two coats of decking oil. Renting a high-pressure cleaner costs €19 excluding VAT per day and a vibratory sander costs €8 excluding VAT per day, which is a fraction of the cost of replacing the entire terrace.

Now that you know how to treat wood, all that remains is to solve the technical side. To prepare wood before painting, you don't need to buy machines that you'll use once every few years. In Ramirente , in the hand tools category, you can rent an orbital sander for fine sanding and a belt sander for removing old paint. In the small equipment section, you'll find high-pressure cleaners and industrial vacuum cleaners that are suitable for both washing the terrace and extracting dust during sanding.

If you are not sure which machine is suitable for your wood or surface, take advantage of professional advice . The branch will advise you on the selection of equipment and accessories, for example sandpaper with the appropriate grain size.

Treat the wood no later than October, when it is dry and the outside temperature is consistently above +5 °C. Most of the success comes from surface preparation: washing, removing old paint and sanding. Choose oil for the terrace, and stain or topcoat for the fence and gazebo, and always apply at least two coats.