How to Restore Timber Sash Windows in Cambridge
Many homes in Cambridge have sash windows that are traditional and homeowners are proud of the way they look. However, sash windows can get stuck and be difficult to open or close. This is usually due to moisture which can cause the wood to swell.
Traditionally, windows made of box sash utilized chains or cotton cords and weights made of lead to operate. Modern sash windows feature hidden springs to solve this problem.
1. Aesthetics
Timber sash windows, in contrast to PVC-u windows that are made in imperial sizes that are modular, can be reconstructed to their original dimensions. This allows the restoration of timber sash windows in order to meet the current energy requirements and conform to conservation area regulations. It also comes with a window that is far superior to uPVC alternatives.
Sliding windows with sash were initially only found in large buildings or public buildings, but the production process became cheaper and craftsmen could make larger frames with more glass. In the 18th century, sash windows were the dominant wooden design in most British properties. Since they were easy to open sash windows allowed light into rooms without the need for curtains.
The early windows were made of clear glass, but by the 17th Century, sash windows began to become more attractive. They started with coloured glazing bars, also known as mullions. They were expensive at the time but as glass production improved and cost-effective, they became a part of many of the period homes.
In the 19th century, it was possible to make large, strong glass that did not need support bars. This allowed the frame to be made bigger and, in turn, gave an improved view. This was an important innovation.
The introduction of the double-hung sliding sash was another important improvement that was made at the end of the I920s and beginning of the I930s. This allowed both the upper and lower sash to be opened simultaneously, and allowed for better ventilation to a building.
Oak was used for older and more luxurious buildings. A split bead divides the two sashes, and it is essential that it is maintained in order to avoid rattles and draughts. The sash pulleys, idler wheels and sash rollers are also vital for the proper operation of the window.
2. Energy efficiency
As larger and clearer sheets of glass became available, sash window began replacing hinged casements. They were coated with plate glass that was placed within timber frames with rebates and then pinned with glazing sprigs, and then putty on both sides to create a watertight seal. This kind of glazing gradually superseded the leaded light bulbs.
The introduction of sashes led to a need for a much wider range of ironmongery, with the basic fittings being brass pulleys, lead (and later cast iron) weights, sash stops shutter hinges and knobs as well as a range of fasteners that secured the sashes into the right place. These were usually decorated with designs, inscriptions, and patterns engraved to identify the maker.
With regular maintenance, sash windows are extremely energy efficient. If they are not maintained they could become noisy. Draughts can also be caused by the breakdown of paint and putty. This can be remedied by using wood-to-timber repair products that are specifically designed for this purpose.
The replacement window industry relies on the belief that traditional windows are rotten and beyond economical repair, whereas they are able to be maintained with just a little care. However, repairs to these windows can be expensive and involve considerable disruption to the home. Many homeowners choose to replace their windows using PVC-u from a 'one-stop shop' installation company. They can replace all windows in a home in one day, saving time and avoiding the need for various tradesmen to coordinate. These windows can be equipped with energy-saving double glazing to get more energy efficient ratings than a traditional sash window. However double-glazed windows cannot replicate the section and proportions of the sashes made of timber from the past.
3. Security
It is possible to secure windows that are traditional without compromising their appearance. Ironmongery such as mortice bolts, sash chain, and sash lock can be used. They can be fitted in a way that the window remains capable of being opened to allow ventilation or cleaning. They are generally unobtrusive, as they are designed to complement the sash window. They can be used alongside traditional sash-window catches, which must be replaced by more robust versions (such ones that have double screws) or spring levers to decrease the risk of them being hammered open.
Sash-window frames are traditionally constructed from oak or slow-grown deal. If the glazing bars are still in good condition, they should be retained. Where feasible, the cills made of timber should be replaced with wood that matches. PVC-U companies usually provide a one-stop shop installation service, removing and replacing windows on an entire home in one day, without the need to engage other tradespeople, or coordinate visits from different suppliers.
4. Ventilation
When sash windows first introduced in the 17th century they allowed a substantial amount of light to flood into structures. By the end 18th century, they had been modified to allow more light could be let into rooms. Larger glass panes were also made. The result was a lighter appearance and windows with more elegance.
Sash windows were introduced, which required a new range ironmongery. Early window repair cambridge pulleys were made from wood, while later Victorian ones were made from brass or a mixture of wood and lead, and there were a variety of shutter hinges and knobs. These ironmongery elements should always be maintained and cleaned so that the quality of their design can be appreciated.
To ensure they remain in good condition, wooden windows need to be maintained. A lack of attention to them regularly could result in:
Sashes that don't slide effortlessly.
Holes in the frame that allow water to get in and cause damage and decay.
break down of putty, allowing water to penetrate, which can lead to decay in the frame and cill.
In the I920s and I930s steel casement windows gained popularity due to their durability, slim and cheap and were in line with the trend for healthy living. However, research has shown that traditional softwood sash windows can be just as thermally efficient as double-glazed PVC-u windows and can be more attractive than the sleek lines of contemporary casement windows.
The replacement window industry has made a significant effort to convince homeowners that their old windows are old, dirty, and beyond repair. However, many old windows made of timber are in good condition and, with minor repairs, could easily be maintained for years to be.
5. Maintenance
The traditional sash windows need regular maintenance and inspection. Inability to maintain it properly can result in the sash cords breaking, a lot of wear on the glazing bars and degradation of the paint and putty. The removal of sashes could also result in structural movement within the frame which causes the sash to become misaligned and not closing properly. It is also possible for the sash be stuck or fixed in an open position, which can let water and draughts enter the structure.
Moisture penetration is the most common cause of damage to windows made of timber. This can be avoided by thorough painting, regular repairs and the elimination of the source of dampness. Wet rot is easily identified by the wavy look of the existing paint which can be stripped away to reveal soft, rotting wood. Any timber that is rotting should be cut off and the affected area carefully scarfed or pieced in using replacements made from the same type of timber as the ones that remain. This method of repair increases the amount original fabric and is one of most non-invasive methods to treat wood-to-timber rot.
The use of a resin-based wood consolidant is an alternative to the traditional method of sanding and staining. This is brushed on the surface of the wood to protect it and stabilise it. It is particularly useful for the treatment of sash cords and pulleys which can help stop breakage.
It is essential to preserve and not replace any historic ironmongery, like stay latches and sash latches. It is difficult to replace these items without altering their original design. It is also advised that modern fittings made of aluminium like sashlifts, as well as chainstays, should be avoided since they can cause deterioration and corrosion of timber frames and sashes.