Maintaining Timber Windows

A well-maintained timber window is an important element of the historical fabric of a structure. It reflects in different degrees, the materials and technologies of the time in which it was constructed, the craftsmanship and architectural taste.

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

Durability

Timber windows were made to last for centuries. However, they do need to be maintained to ensure that they look good and operating properly. Maintenance tasks include sash cord repairs and retightening sash pulleys and painting. The demand for enhancing windows made of timber to increase efficiency in energy use is also growing. This can involve replacing old glazing units, fixing the window rebates that are in place, or installing new cills for better air sealing.

One of the main issues with traditional windows is the damage caused by corrosion of the paintwork. This is particularly important when it comes to sash windows because the gaps between sashes can be extremely large. In these instances water can enter the paint film and cause rotting to the putty or wood beneath. Weather conditions that are not ideal can accelerate the decay. To prevent this from happening, windows need to be painted regularly with an exterior wood paint.

In addition to repainting, areas that have corroded should be repaired with an adhesive-based repair product. This will ensure that the maximum possible amount of the original fabric remains. It is essential to limit the number of holes made into the frame in order to allow cable entry, since they can let in moisture and cause decay.

The wall's structural movement can cause distortions in the frame and the sash. This can result in the sash not fitting properly and jamming or sticking into the opening, or breaking glass. Most often, this is corrected by the fitting of new sash boxes made from slow grown deal (pine) or oak. The cill should be made from a sturdy hardwood such as oak to avoid differential movement between the new and existing work.

To reduce the risk, there are now a variety of companies that manufacture Boston pattern sash made of wood that will fit most existing openings. The sash is available in various sizes and finishes that will fit the needs of modern-day homeowners. Together with quadruple draught strips and improved thermal insulation, these sashes can make a significant improvements to the energy efficiency of a home.

Aesthetics

A lot of old timber frames have a great aesthetic appeal because they display, in a certain form, the quality of the wood technology, the construction process, and the architectural style of the time they were constructed. They may have significant historical value on their own. This is especially true of early windows that were not glazed in timber-framed structures, where the great majority were simply a series of openings within the frame, which were divided horizontally into mullions, and vertically into iron or wood bars to deter intruders.

Traditional timber window joinery can be a stunning element of a structure and it is important to keep its appearance. It is vital that any decay that results from moisture penetration should be immediately stopped once it is recognised. It is best to do this by thorough painting, especially if there is damage or degradation. It is best to use paints that are designed to be used in a system (primer undercoat and finish), and to adhere to the manufacturer's recommendations for preparation and number of coats at each stage.

The fungus that causes wet rot can quickly spread in old windows made of wood. To prevent this from happening, remove any rotten or damaged parts as quickly as you can. The replacement of wood that is rotting should be done with care and with a slow-growing deal (pine) and, wherever possible, the same species as that which is being removed to avoid differential movement between the new and old timbers.

Glass became cheaper and more abundant in the late medieval era and into the 17th century. In the process, the Double Glazed Door Repairs openings in timber-framed homes became more complex with moulded mullions and traceries, made of wood and cills that protruded deep. In recent years, glass was pinned into frames that were rebated with glazing sprigs instead of lead cames. This method of glazing not only makes the windows less likely to leak and also allows larger sheets of glass to be used than would have been possible otherwise without the use of leaded lights.

Energy efficiency

Traditional timber windows offer excellent energy efficiency due to their thickness and multi-layer construction. They also pay attentive attention to detail. They also have large glass areas and projection cills which reduce air infiltration. Windows can be designed to improve their energy efficiency by draught-proofing and secondary glazing. It is important to remember that these measures must be taken into consideration in relation to the overall appearance and integrity of the original windows.

Therefore, keeping existing historic windows that require repair instead of replacing them is logical especially when their thermal enhancements can be achieved cost-effectively through simple repairs and improvements. The windows of the past often have historical significance that shows a variety of technological advancement and changes in architectural taste. The pressures to replace these windows are usually based on the assumption that windows that are old will need to be replaced in the near future, but most are still capable of providing service for 150, 200 and even 250 years if they are properly maintained.

It is crucial to recognize that the decay issues that are that are typical of timber windows can be avoided by thorough maintenance and swift repairs. In addition it is crucial to identify damp penetration problems and to remedy them quickly to avoid major damage. Paint deterioration that occurs early can be a problem because it allows moisture to penetrate into the wood, which can cause wet rot. It is not uncommon for this type of damage to go unnoticed until paintwork starts to crack or turn wavy. However, it could cause structural damage and further decay.

A high-quality paint will prevent this moisture penetration. To prevent condensation and mould it is crucial to keep the paintwork as clean as it can be. The use of modern synthetic paints could be a problem since they are typically formulated to be water-resistant, and this can lead to the formation of mildew inside the window frame.

The majority of windows from the past were manufactured from timber containing a high proportion of sapwood. The timbers will deteriorate quickly when exposed to moist weather conditions, but they can be preserved with an extensive preservative treatment prior to when they are put to use. It is crucial to select the appropriate type of wood for the site and climate, as these variables will affect the durability of the joinery. Local window manufacturers offer a wide range of sash timbers that can be made to fit the historic openings. They can be made according to the standard Boston pattern dimensions or to specific sizes that are in keeping with the architectural style of historic buildings.

Maintenance

The lifespan of windows made of timber can be extended considerably by regular inspection, careful redecoration and timely repair. The primary cause of wood decay is moisture leaking through deteriorated paint and putty. This can be avoided with 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. Repairs can be made to many traditional timber window designs without removing the frame. This should be done whenever possible. Peeling or loose paint should be removed carefully and sanded lightly to increase the 'key' of the surface and facilitate a better adhesion of the new coating. It is important to not remove old paint layers, which could have historical significance.

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

Replacement of windows made of traditional PVC-u can be an appealing option, particularly when the installer provides an "all-in-one" installation that takes care of both removal and replacement windows cambridge within a day. It is essential that installers of replacement windows have a thorough understanding of the history and design of traditional timber frames. This will allow them to make appropriate suggestions for improvements to energy efficiency and other technical improvements that will not harm the character of a historic building. Those who provide replacement windows must be registered under a Competent Persons Scheme, such as FENSA. This will ensure that replacement windows are approved under Building Regulations as a suitable alternative. A skilled carpenter can put in PVC-u windows that conform to the original building's style. This is particularly applicable when windows are located within listed buildings or conservation areas.