Maintaining Timber Windows

A well-maintained timber window is a crucial part of the historic fabric of a building. It demonstrates in various degrees the different materials and technologies as well as the craftsmanship and architectural style of the time period from which it dates.

Whenever possible repairs to existing windows are required, they should be carried out in-situ. Repairing the most deteriorated areas of decay can be done with the help of specialized resin-based systems.

Durability

The timber windows in many historic buildings were made to last for hundreds of years. But, they have to be maintained to ensure they look great and working properly. The most common maintenance tasks include repairs to sash cords, re-tightening sash pulleys, and painting. The demand for enhancing timber windows to improve efficiency and energy efficiency is also increasing. This may include replacing old glazing units, fixing existing window maintenance rebates or installing new cills for improved air seal.

The corrosion of paintwork is a major problem with traditional windows. This is particularly important in the case of sash windows because the gaps between sashes may be quite large. In these situations water may get through the paint film and cause decay of the putty and the wood beneath. Poor weather conditions can exacerbate the decay. To stop this from happening windows, they should be regularly painted with a suitable exterior wood paint.

In addition to repainting, areas that have corroded must be repaired using the help of a resin-based repair solution. This will ensure that the maximum possible amount of the original fabric is preserved. It is also essential to limit the number of holes drilled into the frame to allow cable entry, as they could let in water and cause decay.

Another major issue with older windows is structural movement in the wall, which could cause deformation of the frame and the sash. This can result in sash not fitting correctly jamming, sticking or sagging in the opening, and even broken glass. This can often be fixed through the installation of new sash boxes made from slow grown deal (pine) or oak. The cill must be constructed from durable hardwood such as oak to avoid differential movement between the existing and new work.

There are several companies that make Boston pattern wooden sash to fit into the majority of existing openings. They are available in a variety of sizes and finishes that fit the needs of modern-day homeowners. The new sash, coupled with quadruple draft strips and a better thermal insulation, can make a huge difference to the energy-efficiency of a home.

Aesthetics

Many old timber frames possess a dazzling aesthetic appeal, since they show, in some shape, the materials technology, the construction process, and the architectural style of the time they were made. They may have significant historical value on their own. This is especially true of early unglazed windows in timber-framed structures, where the majority were simply a series of openings within frames of structural construction, which were divided horizontally by mullions with vertical wood or iron bars in order to keep out intrusions.

It is essential to preserve the appearance of traditional timber window joinery. When you spot any signs of decay due to water penetration it is essential to stop it. This can be done by painting thoroughly, especially in areas where there has already been damage or deterioration. It is advisable to use paints designed to be used as part of a system (primer, undercoat and finish) and follow the manufacturer's instructions in terms of preparation and the amount of coats required at each stage.

Wet rot is a typical problem for old timber windows. The best way to stop it developing is to remove sections that are damaged or rotten immediately to prevent the spread of the fungus responsible for it. Replace rotting wood with slow-growing deal (pine), and when possible, the exact type of timber as the one that is being removed, to prevent any differential movement.

Glass became cheaper and more abundant in the late medieval period and into the 17th century. In the process, the glazed openings in timber-framed homes were more elaborate, with moulded mullions, tracery made of wood and cills that protruded deep. In recent years, glazing was fixed into rebated frames with glazing sprigs rather than lead cames. This method of glazing not only makes the windows less likely to leak and break, but also allows larger sheets of glass to be employed than would be possible otherwise without the use of led lights.

Energy efficiency

Traditional timber windows have excellent energy efficiency due to their thickness, multi-layer construction and very careful attention to detailing. The large glass surfaces, the deep projection cills and wide double glazing near me areas help to reduce air infiltration. With secondary double glazing repairs and draught proofing, windows can be upgraded to improve their energy efficiency. It is essential to remember that these measures should be considered when it comes to the overall appearance and integrity of the original windows.

As a result, retaining old windows that require repair rather than replacing them is sensible particularly when thermal enhancements can be made economically through simple repairs and improvements. Older windows typically have historical significance that illustrates a variety of technical development and changes in architectural taste. The pressures to replace such windows are generally based on the assumption that windows of the past will require replacement in the near future, but most are still capable of serving for 150, 200 and even 250 years if properly maintained.

It is crucial to understand that decay issues with traditional timber windows are avoidable with timely and thorough repairs. It is also important to recognize damp issues and correct them swiftly in order to avoid major damage. The early deterioration of paint is a particular problem, as it allows moisture to penetrate the wood and cause wet rot. It is not uncommon for this damage to go undetected until the paintwork begins to crack or become wavy. However, it can cause structural damage and further decay.

A good quality paint will stop this moisture penetration. It is also important to keep the paintwork in good condition to avoid condensation and the growth of mould. The use of modern synthetic paints could be a problem, as they are often formulated to be water-resistant, and this can lead to the formation of mildew within the window frame.

The majority of older windows were manufactured from timber containing an extensive proportion of sapwood. These timbers can deteriorate very quickly when exposed to moist weather, however they can be protected by a thorough preservative treatment before they are put to use. It is crucial to select the right kind of wood for the location and climate, as these factors can affect the durability of the joinery. Local window manufacturers provide a wide range of timber sash which can be made to fit the historic openings. They can be constructed to the standard Boston pattern dimensions, or to custom dimensions that are compatible with the historic architecture.

Maintenance

The life of timber windows can be extended considerably by regular inspection as well as a careful redecoration and prompt repair. The most common cause of decay is moisture intrusion through the deterioration of paint and putty. This can be prevented by using a quality wood preservative and painting the wood thoroughly.

It is important that repairs to old sash and casement windows are properly executed and completed with the minimum disturbance. Many of the traditional designs for timber windows can be repaired without dismantling the frame, and this method should be taken whenever feasible. Paint that is peeling or loose should be removed carefully and sanded lightly to increase the "key" of the surface and allow for an easier adhesion of the new coating. It is important to avoid removing old paint layers that could have historical significance.

If a piece of timber is rotten, the best way to proceed is to take out the rotten material and replace it with spliced-in timber inserts that are shaped to match existing profiles. The inserted wood should also be treated with wood preservative and the connection between the timber cill and the masonry sub-cill should be sealed.

It's tempting to replace traditional windows with PVC u, particularly when the installer provides an 'all-in-one' installation which includes both replacement and removal in one day. However, it is crucial that the person who installs windows replacement has a thorough knowledge of the construction and history of traditional wooden frames. This will allow them to make the appropriate suggestions for improvements to energy efficiency and other technical improvements that do not alter the historical character of a building. Those providing replacement windows should be registered with a Competent Persons Scheme like FENSA. This will ensure that the replacements are approved as a suitable solution under Building Regulations. It is quite possible for a skilled and experienced carpenter to install PVC-u windows that match the character of the original building. This is especially true where windows are installed in listed buildings or conservation areas.