Maintaining Timber Windows
A well-maintained and maintained timber window is a crucial element of the historical fabric of a structure. It illustrates in varying degrees the various materials and techniques design, craftsmanship and aesthetics of the time period that it was built in.
Whenever possible repairs to existing windows should be made in situ. Repairing the worst areas of decay can be accomplished by using specialized resin-based systems.
Durability
Timber windows were designed to last for centuries. However, they need to be maintained to ensure that they look great and working correctly. The most frequently-asked maintenance tasks include sash-cord repairs as well as tightening sash pulleys and painting. There is also a rising demand to upgrade timber windows to increase the efficiency of energy. This can involve replacing old glass units, repairing existing window rebates or putting up new cills that allow for better air sealing.
The corrosion of paintwork is a major problem with traditional windows. This is especially important where windows with sash are involved since the gaps between sashes can be very large. In these situations water can get into paint film and cause rotting to the wood or putty beneath. The rotting can be exacerbated by poor weather conditions. To stop this from happening windows from becoming rotten, they must be painted regularly using an exterior wood paint that is suitable.
In addition to repainting, corroded areas need to be repaired with a resin-based repair product. This will ensure the maximum amount of the original fabric is retained. It is also necessary to minimise the number of holes you drill into the frame for cable entry, as they could admit water and lead to decay.
The structural movement of the wall can also lead to deformations in the frame and the sash. This can result in the sash not fitting properly, jamming or sticking in the opening, and even broken glass. Most often, this is corrected by fitting new sash boxes that have been constructed from slow-growing deal (pine) or oak. The cill needs to be constructed from a sturdy hardwood, like oak, to avoid shifting between the new and old work.
To alleviate this issue to reduce the risk of this happening, there are a number of companies who produce Boston pattern sash made of wood that can be fitted into most openings. These sash are available in a range of sizes and finishes to meet the needs of the modern homeowner. The new sash, combined with quadruple draft strip and a better thermal insulation, can significantly improve the efficiency of your home's energy usage.
Aesthetics
A lot of old timber frames have a high aesthetic appeal, as they reflect, in some shape, the materials technology, the construction process, and the architectural style of the time they were constructed. They could also have a significant historical significance in their own right. This is especially true for early windows that were not glazed in timber-framed buildings, which were simply a series of openings within the structural frame sub-divided horizontally into mullions, and vertically into wood or iron bars to deter intrusions.
Traditional window joinery made from timber is a beautiful element of a structure and it is important to keep it looking good. As soon as you notice any signs of decay caused by water penetration it is essential to stop it. It is recommended to do this with thorough painting, especially where there has been damage or deterioration. It is recommended to use paints designed to be used as part of a system (primer undercoat, finish) and to follow the manufacturer's recommendations regarding preparation and number of coats required at each stage.
The fungus responsible for wet rot can spread quickly in old windows made of timber. To prevent this from happening, remove any damaged or rotten components as quickly as you can. Replace rotting wood with slow-grown deal (pine), and if possible, the same type of timber as the one that is being removed, to prevent any differential movement.
In the late the 17th and early the medieval periods, glass became cheaper and more abundant, and the openings for glazed glass in timber-framed buildings gradually became more sophisticated, with tracery made of wood as well as moulded mullions and projection cills. In recent years, glass was fixed to rebated frames with glazing sprigs instead of lead cames. This method of glazing not only makes the windows less likely to leak, but also allows for wider sheets of clearer glass to be utilized than would have been possible without the use of leaded lights.
Energy efficiency
Traditional timber windows provide a good energy performance due to their thickness, multi-layer construction and very careful attention to detailing. They also feature large glass areas and projection cills which reduce air infiltration. With secondary glazing and draught proofing, windows can be upgraded to increase their energy efficiency. It is crucial to keep in mind that these measures must be taken into consideration when it comes to the overall integrity and appearance of the original windows.
It is logical to repair or upgrade existing windows, rather than replacing them, particularly when improvement in energy efficiency can be made through simple repairs. Historic windows often have an historic value that demonstrates a range of technical development and changes in architectural taste. The pressures to replace these windows are generally based on the assumption that the windows of the past will require replacement in the near future, but the majority of them are capable of serving for 150, 200 or even 250 years if properly maintained.
It is essential to realize that decay problems with traditional timber windows can be avoidable with prompt and thorough repairs. In addition, it is essential to recognize damp penetration issues and address them swiftly to prevent serious damage. Paint deterioration that occurs early could be a problem as it allows moisture to penetrate into the wood, which can cause wet rot. This damage is often not evident until the paintwork is damaged or wavy however, it can cause serious structural damage and can lead to further decay.
A high-quality paint will stop this moisture from entering. To avoid condensation and mould it is crucial to keep the paintwork as clean as possible. The use of modern synthetic paints can pose a problem because they are usually formulated to be water-resistant, and this can result in the formation of mildew within the window frame.
Most older windows were made from sapwood-rich wood. These timbers can deteriorate very rapidly if exposed to wet weather conditions, but they can be protected by a thorough treatment of preservative before they are put to use. It is crucial to select the right type of wood for your location and climate, as these variables will affect the durability of the joinery. Local window manufacturers create a variety of timber sash that can be tailored to fit specific openings from the past. They can be constructed to the standard Boston pattern dimensions or to specific dimensions that upvc window repairs cambridge are compatible with the historic architecture.
Maintenance
The lifespan of windows made of timber can be extended significantly by regular inspection, careful redecoration and prompt repair. The most common cause of decay is moisture infiltration through deteriorated paint and putty. This can be avoided by careful painting and using high-quality wood preservative.
Repairs to sash windows that are old and window frames made of casement should be handled with care and with minimal disruption. It is possible to repair the majority of traditional wooden window designs without having to remove the frame. This should be done whenever possible. Remove loose or peeling paint and lightly sand the area to improve the "key" of the surface. This will allow the new coating to stick better. It is essential to not remove old paint layers, which may have historical significance.
Where a section of timber has begun to decay, the best course of action is to eliminate the rotten material and replace it with spliced-in timber inserts that are shaped to match existing profiles. The timber inserts should be treated with wood preservative, and the joint between the masonry sub-cill and the timber cill should be sealed.
It can be tempting to replace traditional windows with PVC u, especially when the installer provides an installation that includes removal and replacement within a single day. It is essential that installers of replacement windows are aware of the history and construction of traditional timber frames. This will enable them to make the appropriate recommendations for energy efficiency improvements as well as other technological advancements that won't affect the appearance of an historic building. Window replacements should be registered with a Competent Persons Scheme like FENSA. This will ensure the replacements are deemed to be approved by the Building Regulations as a suitable alternative. It is, of course, possible for an experienced and skilled carpenter to install PVC-U windows that are sympathetic to the the original building. This is especially true where windows are installed in listed buildings or conservation areas.