How to Use Wood Fillers to Repair Timber Windows
Many timber windows are affected by rot which can lead to a variety of issues, including peeling paint windows that stick, and rattling. Repairing your historic windows can improve their energy efficiency and ensure they remain in good shape.
The first step is to determine the extent of rot. This can be accomplished by squeezing the wood with an instrument that is sharp and checking the windows for damp areas, sunken corners, and crumbly timber.
Wood Fillers
Wood fillers are an excellent method of sealing cracks and crevices in old wooden windows. They are made from sawdust, or other wood shavings, soaked in a petroleum or water base. They can be used to repair windowsills that are rotting, frames, or sash windows. They can be tinted or stained to match the wood and then painted. However, it is essential to choose the right kind of filler for your needs. This guide will help you pick the best one for your project.
The first step is to strip the existing paint, particularly from the window sill. This will reveal any areas of rot that will require treatment, and let you assess the condition of the wood. If the window is suffering from too many rots, it might not be salvageable.

Next, you need to determine the cause of the decay. If the wood has become unstable because of a lack of support, it will have to be treated with an abrasive. This will stabilize the wood and can be applied using the use of a paintbrush or similar device. After this, the rotted wood can be treated using an water-based filler like Bondo(r). Water-based fillers for wood tend to dry quicker than solvent-based fillers. They are also easier to clean up as they don't require acetone to remove.
Use standard acrylic latex sealant to fill in the gaps between window frames and wall openings. This will work fine and is easy to apply and will accept most paints. It is crucial to examine the frame for rot before applying before sanding it, as excessive sanding can make the gap too wide, making the window prone to leaks.
Another option is to use a high-performance epoxy filler. This kind of epoxy filler is created to endure extreme temperatures, humidity, and heat. It can be sanded or cut when it is hard, giving you more control over your final outcome. It is important to note that this type of filler will absorb stain differently than natural wood and it is unlikely that an exact color match can be obtained.
Spliced Repairs
Timber windows add a touch elegance to any home and, with the proper care, they can last for a long time. However, as time passes they can become damaged and in need of repair. Damaged window frames can be susceptible to insect infestation, and rot. They must be treated right away to prevent further deterioration.
To ensure that no water can get into the sill or rotted timber and to help insure that damp fungus does not re-infest the area a repair of the splice is often required. The area is cleaned of decay and fungus and the timber is then spliced and resin bonded with the window care system to insure that the joint will not move and allow moisture in.
This is an effective way to replace rotten wood and is particularly suitable in areas where splicing is more cost-effective than replacing the entire sill. This type of repair can also be used to replace a tiny section that is rotten, but has not affected the surrounding woods.
It is important to use high-quality timber to repair the splice. This will help hold the cement and resist any movement. It is essential to remove any emulsion that has been spliced and avoid applying too much film cement, which can cause it to leak and damage the lining. It is a good idea, once the splice has been completed, to tape the edges to keep the repair in place. Then, apply the film adhesive working from the center to the outside (fig. 11.1 iv).
It is recommended that you encapsulate the entire repaired area with an encapsulation and prevention compound to prevent future degradation. It is also advisable to stain or paint regularly the timbers to protect them from UV light and to ensure that any preservative used is still in contact with the wood, ensuring the greatest protection and durability.
Replacement Parts
Timber windows can add a lot of character to a home. However, over time they can be damaged by dampness and extremes of weather. Regular maintenance can prevent the need for costly replacements, and help to extend their lifespan.
If the wood inside the frame of a window begins to get rotten, it could cause problems with the window's operation and even cause it to collapse. If the rot is severe it could be required to replace the wood completely, which could be expensive. With the proper maintenance and care the window made of wood can be repaired to its original condition without the need for a complete replacement.
Repainting your windows made of timber is a great way to maintain their appearance. It's a simple process, and it can bring new life to windows. It's important to ensure the surface is properly cleaned prior to painting, which includes stripping and sanding paint layers. Natural linseed oils are a good choice as they provide excellent protection and are available in a range of colours. It is important to not clog the draught strip paint, as this could cause them to stop working properly.
Before making any repairs to your timber windows it is crucial to make sure that the wood is dry. This is difficult to do with the naked eye, but it is possible to make use of a moisture meter. Moisture can provide the ideal conditions for wet-rot to develop in timber, which can cause significant damage.
Cracks, splinters and soft spots should be addressed immediately since they could be a stepping stone to decay. Test suspected soft areas by applying a small amount of pressure. A healthy, solid wood will feel solid while rotting timber will depress easily.
To stop upvc window repairs from entering the home, it is essential to inspect and adjust the draught seals that surround a timber window regularly. To ensure that a timber window is secure, the handles and hinges can be tightened. They should be maintained in good order to increase the efficiency of your window.
Replacement Windows
Instead of replacing the current timber window with a new uPVC one, it is sometimes possible to restore the original wooden windows. It could save you money and increase the value of your house. It may only take repainting, re-sanding or filling any gaps, depending on the condition of your wood window.
The sash is usually the first part to begin to show signs of wear and tear and should be addressed first. In this region, you may find rotten wood and missing or deteriorated glass putty. This will ensure the window is sealed correctly and stop water from getting into the building.
Re-sanding and repainting the windows can help to give it a new lease of life and bring it back to its previous glory. A good sanding process will protect the wood and ensure that the paintwork lasts many years.
If the sash has been severely damaged or deteriorated, it can be substituted with a wooden replacement made to match the opening size. This will allow the same amount of light to pass through the room, and won't alter the original features of the window, for example muntins.
In some areas of the country and especially in conservation zones, laws on planning protect historical details such as ornamental brickwork and plasterwork as well like wooden window frames. If this is the case then you'll be unable to install a uPVC window replacement in the old opening because it won't fit and could damage the brickwork that surrounds the opening.
Wooden frames are more difficult to maintain than uPVC, and require regular sanding, filling and painting. However this can add to the aesthetics of your home. There are uPVC windows that require less maintenance. It is worth researching before replacing your windows made of timber.