Before filling any rotten areas, it's important to remove as much loose and rotten wood as possible. We recommend treating the affected area with Ronseal Wet Rot Wood Hardener first to stabilise and harden the damaged and immediately surrounding areas. Once treated and prepped, any rotten or damaged areas can be filled using Ronseal High Performance Wood Filler. Once this has set hard the repaired area should be sanded smooth ready for applying an exterior wood primer and paint.
This can depend on which part of the window frame is to be filled and what type of finish the window frame will be coated with once repaired. Some wood fillers are only suitable for interior use while others are formulated for exterior use. If the window frame is to be painted after repair it doesn't matter if you use a filler that has a solid opaque colour as it will be covered by the paint. If the window is being treated with a semi-translucent coating system such as Sikkens or Sadolin, you'll need the repaired area to look more like wood so we recommend Fiddes Wood Filler Gel. These types of filler are mixed with sanding dust, (it is preferable to use dust from the wood that is to be filled which helps to produce a better colour match), to produce a wood filler paste that is essentially half made of wood and therefore will absorb the wood finishing product in a more similar way to the wood surrounding it. Once coated with a semi-translucent finish, the repaired area will be less visible than with a standard opaque wood filler.
See our full range of fillers suitable for windows, frames and sills.
There are several flexible wood fillers that are ideal for sealing small gaps between window frames and walls. Bona Gap Master comes in a range of colours and is ideal for sealing interior gaps between window frames and walls. Cuprinol All Purpose Wood Filler, also available in several colours can be used for both interior and exterior gaps.
Although there are many coloured exterior varnishes, 2 brands that are considered by many to be the best in the market are Sadolin and Sikkens. These stain systems offer excellent durability by combining a base stain with a matching colour top coat. These top coats have a wear layer that can be easily maintained by re-coating when it starts to lose it's sheen or weatherproofing properties.
This products are ideal for all soft and hardwood timbers although some exotic hardwoods such as Teak and Iroko require more careful preparation prior to staining.
Most exterior wood preservatives will do the trick with a wide range of clear and colour options to consider. A few popular options are Ronseal Total Wood Preservative and Barrettine Premier Wood Preserver. Both of these products are solvent-based and contain a small amount of wax. If a water-based option is preferred, consider Cuprinol Ultimate Garden Wood Preserver or Sadolin Wood Preserver, both of which are low VOC, water-based formulations.
If painting the frames with a water-based paint or varnish, it's important to use a wax-free preserver, such as Barrettine Premier Universal Preserver before painting for maximum possible compatibility.
We have a number of wood paints suitable for exterior windows, frames and sills, one of these is Ronseal 10 Year Weatherproof Wood Paint - Gloss. Available in a range of colours including pure brilliant white and black, this weatherproof wood paint offers up to 10 years wood protection. If a satin finish is preferred, consider Ronseal 10 Year Weatherproof Wood Paint - Satin..
As with all wood finishing products, the key to a long-lasting finish is in the preparation and the application of the product.
Disclaimer: Whilst every attempt has been made to provide product information that is as accurate as possible, it's important to clarify that trees and the wood that they produce can be affected by many factors. For example, the same species of tree grown in the same wood, even in close proximity, will be affected by age along with the amount of sunlight and water they receive. Other naturally occurring biological and environmental factors will also influence the density and grain of the wood as well as the moisture and oil content of the timber. No two trees are the same, meaning each piece of wood has the potential to look and react differently to the same wood finish. For example, product adhesion, colour variations, absorption rates and sheen levels. It is for this reason that we always strongly recommend carrying out test areas before starting any project