First aid for wood rot

Don't worry, wood rot may be annoying, but it is quite easy to repair and prevent. When it comes to wood rot, the sooner you catch it, the better. That is why we strongly advise you to inspect all your woodwork every season. This way, you will always catch it in time and never face unpleasant surprises. Also, make sure to clean the woodwork regularly. An accumulation of dirt can damage the paint layer of the wood, increasing the risk of wood rot.

Wood rot is unfortunately a common problem, so you are far from being the only victim. Wood rot occurs because moisture can penetrate the woodwork. The penetrating moisture can cause the wood to become moldy, which eventually leads to the wood rotting. The fungi then eat their way through the wood and, in the worst case, can cause irreparable damage. That is why it is good to know how to recognize wood rot and how to repair it. This way, you can always stay ahead of serious damage. Pay close attention: wood rot is not always visible on the outside of the wood, while it eats away at itself completely from the inside.

The perfect breeding ground for wood rot is a combination of humidity above 20% and an outdoor temperature above 18°C. Unfortunately, when dealing with this combination, you can easily suffer from wood rot. Wood rot is a fungus that develops under the following three factors: moisture (at least 20%), heat (more than 4°C), and oxygen.

If these factors are present, there is a high chance that the fungus will settle in the wood to do its work, with all the associated consequences. It is only a matter of time before the first signs of wood rot appear. The main characteristic is discoloration: the wood turns a darker color due to the moisture. The wood also becomes softer. You could test this by poking it. In an advanced stage of wood rot, the wood is dark brown and shrinkage cracks are even visible. When you tap on this wood, it sounds hollow and glazing sealant cannot adhere to it.

Prevention is better than cure. Do you want to prevent wood rot? Then ensure that you adequately protect your beloved wooden surfaces against the factors that can cause wood rot. Osmo products offer high protection against wood rot. With Osmo UV Protection Oil, you protect wooden surfaces against discoloration caused by UV radiation and against all fungi and algae. This product offers the very best protection against sun, weather, and wind, and thus also against wood rot. The UV Protection Oil is available in no fewer than 9 different colors, so there is always a color that you are looking for.

Fortunately for you, we have plenty of products in stock to repair wood rot and get your wood back in top condition. However, make sure you address the cause of the wood rot. If you don't, there is a high chance you will have to repair the wood again next year. Therefore, inspect the sealant joints and check if doors can swing freely. Is this not the case? Then it could be that the paint layer is damaged, allowing moisture to penetrate the wood. Once the culprit has been remedied, it is time to start repairing the wood rot. The step-by-step plan for repairing wood rot is as follows:

Step 1: Remove the rotten wood. Use a scraper or milling tool for this. Work carefully, because if you do not remove all the rotten wood, the remaining fungi can start spreading again. Therefore, ensure that you always remove a generous amount of healthy wood surrounding the rotten spot. Even dry wood can rot, so do not be misled by a dry piece of wood that looks rotten but dry. Absolutely all fungi must be removed. Is the rotten wooden surface to be repaired significantly larger than your fist? Then we recommend replacing this section with new wood. Replacing rotten wood can sometimes be a better solution than repairing the wood.

Step 2: Has all the wood rot been removed? Then let the repair area dry thoroughly. Do this for at least a few days and check regularly whether the area is drying properly.

Step 3: Thoroughly clean and degrease the surface and the intact paint layers with the Osmo Paint Stripper. Thanks to its effective action, this product can dissolve multiple layers of lacquer or paint at once. Stir the paint stripper well and apply it evenly to the surface. Then cover the surface with a thin sheet of plastic and allow the product to soak in thoroughly. Subsequently, test the performance occasionally with a trowel and remove the dissolved layer at the optimal moment. Ensure that you remove the treatment or paint layer completely and leave nothing behind. The treatment time varies depending on the type of treatment, so be careful not to leave the paint stripper on the surface for too long.

Step 4: Once the surface is thoroughly clean and free of paint, it can be filled. For optimal wood treatment, we recommend applying a wood rot preservative first. This product penetrates deep into the wood and ensures that all residues and mold spores are eliminated. It takes approximately six hours to dry. You can find a wood rot preservative at your local building supply store.

Step 5: Once the wood has been sufficiently treated with the impregnating agent, it is ready to be filled. For this, you can use a wood rot filler or an exterior joint sealant. This is also available at your local building supply store. Apply the two-component wood filler and allow it to cure as described on the packaging. Apply the wood filler with a putty knife and then let it dry for at least six hours.

Step 6: When the wood filler has fully cured, the surface can be prepared for finishing. Sanding the surface ensures a seamless transition between the wood and the wood rot repair product. After sanding, make the surface completely dust-free. This provides the best base for when you treat the surface.

Step 7: To prevent wood rot from returning after the repair, it is important to treat your wood properly. Osmo products offer the very best protection against the recurrence of wood rot. For example, choose Osmo UV protection oil to prevent discoloration, bacteria, and fungi. In the mood for a nice color instead? With Osmo Country House Paint, you can easily give your window frames, shed, or fence a sleek look. Country House Paint is available in 21 different colors that can also be mixed together. This allows you to let your creativity run wild and ensures you will always find a color you like.

Want to know more about how to protect exterior wood from moisture? Read our blog about protecting wood from moisture.