Maintaining Timber Windows

A well-maintained wooden window is an essential component of a historical building. It illustrates in varying degrees the different materials and technologies design, craftsmanship and aesthetics of the period from which it originates.

If possible, repairs should be done in-situ. Repairing the most deteriorated areas of decay is possible using proprietary resin-based systems.

Durability

Timber windows were designed to last hundreds of years. They require regular maintenance to keep them looking good. The most frequently-asked maintenance tasks include repairs to sash cords and re-tightening the sash pulleys and painting. There is also a growing demand to upgrade timber windows to increase energy efficiency. This can involve replacing old glazing units, fixing existing window replacement rebates, or installing new cills that allow for improved air sealing.

A key problem with traditional windows is damage caused by corrosion of the paintwork. This is especially important where windows made of sash are involved because the gaps between the sashes can be quite wide. In these circumstances, water can penetrate the paint film and cause rotting of the putty and the wood underneath. The rotting can be exacerbated by poor weather conditions. To prevent this, windows should be regularly painted with an exterior wood paint that is suitable.

In addition to repainting, corroded areas need to be repaired with the help of a resin-based repair solution. This will ensure that the maximum amount of the original fabric is retained. It is crucial to reduce the number of holes drilled into the frame in order to allow cable entry as these can admit moisture and cause decay.

Another issue with older windows is the structural movement within the wall which can lead to deformation of the frame and the sash. This can lead to sash no longer fitting correctly and jamming or sticking to the opening, and damaged glazing. This is often corrected by putting in new sash frames made of slow-grown deal (pine) or oak. The cill should be constructed of a durable hardwood, such as oak, to prevent differential movement between new and older work.

To alleviate this issue, there are now a variety of companies that produce Boston pattern sash made of wood that can be fitted into most openings. These sash come in various sizes and finishes to fit the needs of modern homeowners. In conjunction with quadruple draught strip and a better thermal insulation, these new sash options can make an enormous difference to the energy efficiency of a house.

Aesthetics

A lot of old timber frames have a great aesthetic appeal, as they display, in a certain form, the materials technology, the construction process, and the architectural style of the time they were built. They may also have significant historical significance in their own right. This is especially true for early windows that were not glazed in timber framed buildings which were just a collection of openings in the structural frame sub-divided horizontally into mullions and vertical wood or iron bars to deter invaders.

It is crucial to maintain the appearance of traditional timber window joinery. As soon as you notice any decay caused by the penetration of moisture it is crucial to stop it. This is best accomplished by a thorough painting process, especially in areas that have already suffered damage or degradation. It is best to use paints designed to be used in a set (primer undercoat and finish) and follow the manufacturer's guidelines for preparation and number of coats at each stage.

The fungus responsible for wet rot is able to spread quickly in old windows made of timber. To stop this from happening, remove any damaged or rotten components as quickly as you can. The replacement of rotting timber should be done with care and with a slow-growing deal (pine) and, if feasible, the same species as that which is being removed to avoid differential movement between the new section and existing timbers.

In the late period of the 17th century and the middle of the medieval period, glass became more affordable and abundant, so that the glazed openings in timber-framed buildings gradually became sophisticated with wooden tracery as well as moulded mullions and protruding cills. The glazing was increasingly set within rebated frames and secured with 'glazing sprigs' rather than into lead cames. This method of glazing is not just less prone to leaking but it also allows larger clearer, more transparent sheets of glass to be used in windows than would otherwise have been possible without the need for leaded lights.

Energy efficiency

The traditional timber windows are energy efficient due to their thickness and multilayer construction as well as care for particulars. The large glass areas, the deep projecting cills, and the large glazing areas minimize air infiltration. With secondary glazing and draughtproofing windows can be upgraded to improve their energy efficiency. It is essential to keep in mind that these measures must be taken into consideration in relation to the overall integrity and look of the original windows.

It makes sense to upvc door repair cost or upgrade existing windows that are older rather than replacing them, particularly when improvements in thermal efficiency can be achieved by simple upvc door repairs. Historic windows are often of historical value, as they demonstrate a variety in technological advancement and changes in architectural style. The pressure to replace these windows are typically based on the assumption that the windows that are old will need to be replaced in the near future, however they are capable of serving for 150, 200 or even 250 years if properly maintained.

It is important to recognize that decay issues in traditional timber windows are preventable by quick and thorough repairs. Additionally, it is essential to recognize damp penetration issues and fix them promptly to avoid serious damage. Early paint deterioration is a concern because it allows moisture to get into the wood, which can cause wet rot. It is not uncommon for this type of damage to go unnoticed until the paintwork begins to crack or becomes curly. However, it could cause structural damage and lead to further decay.

A quality paint will stop moisture from entering the paint. It is also essential to keep the paintwork spotless to avoid condensation and mould growth. Modern synthetic paints can be problematic, as they are often made to be water-resistant which can cause the growth of mildew inside the window frame.

The majority of windows from the past were made from timber that contained an extensive proportion of sapwood. The timbers will deteriorate rapidly if exposed to rain, but they can be protected with an extensive preservation treatment prior to use. It is also essential to ensure that the kind of wood used is suitable to the climate and site conditions, since these factors can affect the longevity of the joinery. Local window manufacturers make a range of sash made of timber that can be adapted to fit specific historic openings. They can be built to the standard Boston pattern dimensions, or to custom sizes that fit with the architectural style of historic buildings.

Maintenance

Regular inspections, careful redecoration, and timely repairs can prolong the life of timber windows. The primary cause of decay is the infiltration of moisture through deteriorated putty and paint. This can be prevented by thorough painting and the use of an excellent wood preservative.

Repairs to old sash windows as well as window frames made of casement should be done with care and with minimal disruption. Many traditional timber window designs can be repaired without dismantling the frame, and this approach should be followed whenever possible. Remove any peeling or loose paint and then lightly sand the surface to improve the 'key" of the surface. This will allow the new coating to adhere better. Care should be taken to avoid stripping old paint layers that may have historic value If these are present, it is recommended that a study of the paint be conducted.

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

It can be tempting to replace traditional windows with PVC u, particularly when the installer provides an installation that includes both replacement and removal within a single day. It is, however, vital that the installer of replacement windows has a complete knowledge of the construction and history of traditional wooden frames. This will allow them to make the right suggestions for energy efficiency improvements and other technological upgrades that will not harm the historic character of a building. Window replacements should be registered with a Competent Persons Scheme such as FENSA. This will ensure that the replacements are deemed as a suitable solution under Building Regulations. It is certainly possible for an experienced and skilled carpenter to install PVC-u windows that match the style of the original building. This is especially true where windows are situated in listed buildings and conservation areas.