Maintaining Timber Windows
A well-maintained wooden window is a crucial part of a historic building. It demonstrates in various degrees the materials and technologies as well as the craftsmanship and architectural style of the period from which it dates.
When repairs are feasible to existing windows should be done in situ. Repairing the worst areas of decay can be done using proprietary resin-based systems.
Durability
The timber windows in many historical buildings were made to last for a long time. They do require maintenance to ensure they look good. Maintenance tasks include sash cord repairs as well as tightening the sash pulleys and painting. There is also a growing demand to upgrade timber windows to increase energy efficiency. This can include replacing old glazing units, fixing existing window rebates, or installing new cills to improve air seal.
The deterioration of paintwork is a major issue with traditional windows. This is particularly true when windows made of sash are involved because the gaps between the sashes can be quite large. In these cases water can get into paint film and cause rotting to the wood or putty beneath. The weather can be a factor in accelerating the decay. To prevent this from happening, windows must be painted regularly with an exterior wood paint.
The areas that are damaged should be repaired using resin-based products. This will ensure that the maximum possible amount of the original fabric is preserved. It is crucial to reduce the number of holes that are drilled into the frame in order to allow cable entry, since they can let in moisture and cause decay.
Another major issue with older windows is structural movement in the wall which could cause deformation of the frame and sash. This could result in the sash not fitting properly, sticking or jamming in the opening and broken glazing. Most often, this is corrected by fitting new sash boxes made from slow grown deal (pine) or oak. The cill should be constructed from a sturdy hardwood such as oak to avoid differential movement between the old and new work.
To help reduce this problem There are a number of companies who manufacture Boston pattern wooden sash that will fit most existing openings. The sash is available in a variety of sizes and finishes that meet the requirements of modern-day homeowners. Together with quadruple draught strips and better thermal insulation these new sash options can make significant improvements to the energy efficiency of your home.
Aesthetics
Many old wooden windows have an excellent aesthetic value because they typically demonstrate, in a way the materials and technologies and architectural taste of the time from which they originate. They may have significant historical significance in their own right. This is especially true of windows that were unglazed in the early days of timber framed buildings where the great majority were just a collection of openings in the frame that were subdivided horizontally into mullions and vertical iron or wood bars to deter intrusions.
Traditional window joinery made from timber can be a highly decorative element of a structure and it is important to maintain its appearance. When you spot any signs of decay due to the penetration of moisture, it is important to stop it. This is best accomplished by applying a thorough coat of paint, particularly in areas that have already suffered damage or deterioration. It is advisable to use paints that are specifically designed to be used part of a system (primer undercoat, finish) and follow the manufacturer's guidelines in terms of preparation and the number of coats needed at each stage.
Wet rot is a frequent problem for old timber windows and the best way to stop it growing is to eliminate any damaged or rotten parts as soon as you can to stop the spread of the fungus responsible for it. The replacement of rotting timber should be done with care and using slow grown deal (pine) and, if feasible it is the same species as which is being removed in order to prevent any movement differences between the new and old timbers.
Glass became less expensive and more abundant during the late medieval period and into the 17th century. This led to the glazed openings in timber-framed homes became more complicated with moulded mullions, tracery made of wood and deep projecting cills. In recent years, glass was pinned into rebated frames with glazing sprigs, not lead cames. This method of glazing is not only less prone to leaking but it also allows larger and clearer sheets of glass to be used in the windows than would otherwise be possible without the need for lead lights.
Energy efficiency
Traditional timber windows are energy efficient due to their thickness and multilayer construction as well as care for detail. 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 essential to remember that these measures need to be considered in relation to the overall integrity and look of the original windows.
So, retaining old windows that are in need of repair instead of replacing them makes sense especially when their thermal enhancements can be made economically through simple repairs and upgrades. Historic windows often have historical significance that demonstrates a range of technological advancement and changes in architectural tastes. The pressures to replace such windows are generally based on the assumption that the old windows will need replacement in the near future, but they are capable of providing service for 150, 200 and even 250 years if properly maintained.
It is crucial to understand that decay problems with traditional timber windows can be avoidable with quick and thorough repairs. Additionally, it is essential to identify damp penetration problems and address them swiftly to avoid serious damage. The early deterioration of paint is a major issue, as it allows moisture to penetrate the wood and cause wet rot. It is not uncommon for this type of damage to go undetected until the paintwork begins to crack or becomes wavier. However, it could cause structural damage and further decay.
A paint of good quality will block moisture penetration. To avoid condensation and mould it is essential to keep the paintwork as clean as possible. The use of modern synthetic paints can be problematic, as they are often formulated to be water-resistant, and this may lead to the formation of mildew in the window frame.
The majority of windows from the past were constructed from timber with a high proportion of sapwood. These timbers deteriorate quickly if exposed to rain, but they can be protected with a thorough preservation treatment before use. It is also important to ensure that the kind of wood used is suited to the climate and site conditions, as these elements will influence the durability of the joinery. Local window manufacturers provide various types of timber sash which can be adapted to fit historical openings. They can be built according to the standard Boston pattern dimensions or to specific sizes that fit with the architectural style of historic buildings.
Maintenance
Regular inspection, careful redecoration, and timely repairs can prolong the lifespan of windows made cheap windows cambridge of timber. The main reason for decay is the infiltration of moisture through deteriorated paint and putty. This can be prevented by using a quality wood preservative and thoroughly painting the wood.
Repairs to sash windows that are old and window frames made of casement should be done with care and with minimal disruption. A lot of traditional wooden window designs are repairable without removing the frame, and this approach should be taken whenever feasible. Remove peeling or loose paint and then lightly sand the surface to improve the 'key" of the surface. This will enable the new coating to stick better. It is crucial to not remove old paint layers that may have historical significance.
If a piece of timber is rotten, the best course of action is to remove the rotted material and replace it with spliced-in inserts that are shaped to fit the 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.
Replacement of traditional windows using PVC-u may be an appealing option, particularly when the installer provides an "all-in-one" installation that takes care of both removal and replacement within a day. However, it is crucial that the person who installs windows replacement has a thorough knowledge of the construction and history of traditional timber frames. This will allow them to make the appropriate recommendations for energy-efficiency improvements and other technological upgrades that won't harm the character of a historic building. The window installers who provide replacement windows must be registered with a Competent Persons Scheme such as FENSA. This will ensure that replacement windows are deemed acceptable under Building Regulations as a suitable alternative. A skilled carpenter is able to install PVC-u Windows that are sympathetic to the original building's style. This is particularly applicable when windows are situated within listed buildings or conservation areas.