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 appear. Sash windows can become stuck and be difficult to open or close. This is usually due to moisture which can cause the wood to expand.

Traditionally, box sash windows utilised chains, cotton cords or lead weights to operate. Modern sash windows come with hidden springs to overcome this issue.

1. Aesthetics

Unlike PVC-u windows that are constructed to modular imperial sizes the timber sash windows are able to be restored to their original size. This allows the restoration to meet modern day energy requirements while complying with conservation areas regulations. It also gives windows that have a superior appearance than the upvc door repair alternatives.

Sliding windows with sash were initially only used in large buildings or public buildings. However the production became cheaper and artisans could produce larger frames with more glass. In the late 18th century windows made of sash were the predominant wooden style in a majority of British properties. As they were easy to open sash windows allowed light into rooms without curtains.

The early windows were made of glass that was plain however, in the 17th century the sash windows began to be more decorative. They began with colored glazing bars, also known as mullions. They were costly at the beginning but as glass production became cheaper and more efficient, they became an integral feature in many period houses.

In the 19th century it was possible to manufacture large, sturdy glass that did not need supporting bars. This allowed the frame's size to increase further and this in turn gave a better view from the window. This was a significant advancement.

The introduction of the double-hung sliding sash was a significant improvement that came about in the I920s and the beginning of the I930s. This allowed both the lower and upper sash to be opened simultaneously, and also improved the ventilation of a building.

The most commonly used kind of sash is made from slow-growing deal (pine) however oak was also used in more luxurious buildings and in earlier examples. It is essential to keep the parting bead that divides the sashes. This will stop rattles and draughts. It is also important that sash pulleys and idler wheels are in good condition as these assist in operating the window seal repairs.

2. Energy efficiency

As larger and clearer sheets of glass became available, sash windows began replacing hinged casements. Glass plates were set in rebated timber frames, pinned with glazing sprigs and putty was sprayed on both sides of the frame for watertightness. This form of glazing gradually superseded the leaded light bulbs.

The introduction of sashes resulted in the need for a greater variety of ironmongery, with the most basic fittings being brass pulleys as well as lead (and later cast iron) weights, sash stops, shutter hinges and knobs as well as a range of fasteners that secured the sashes into place. They were often decorated with motifs, inscriptions, and engraved patterns that identified the maker.

With regular maintenance, sash windows can be very energy efficient. However, if they are not maintained, they can become draughty and let in cold air. Putty and paint can cause draughts too. This can be corrected using proprietary wood-to-timber repair products.

The replacement window industry relies on the assumption that old windows are damaged and beyond economical repair, but they can be maintained with a bit of care. However, these repairs are costly and can cause considerable disruption to the home. To prevent this homeowners, many prefer to replace their windows with PVC-u windows made by one of the large "one stop shop" installation companies. They can take down and replace all windows in a house in a single day, avoiding the need to co-ordinate different tradesmen, making the whole process much quicker. These windows can be fitted with 'energy-saving' double glazing to achieve higher energy ratings than traditional sash window. These double-glazed windows aren't capable of resembling the proportions and sections of the sashes made of timber from the past.

3. Security

Traditional windows can be made more secure without compromising their style. Ironmongery, such as mortice bolts, sash chain and sash locks can be installed. They can be fitted in such a way that the window can still be opened to allow ventilation and cleaning. They are usually discrete since they are made to be used in conjunction with sash windows. They can be used with traditional sash window catches. They are best replaced with more robust versions, such as ones that have double screws, or sprung levers, to minimize the possibility of being hammered.

Sash-window frames were made from slow-growing deal or, in more elegant homes they were made from oak. If the glazing bars are still in good condition and are not damaged, they should be left. If possible, the timber cills should be replaced with wood that matches. Many PVC-u firms offer a one-stop installation service. They can take down and replace windows on a complete house in just one day, without involving any other tradespeople.

4. Ventilation

When sash windows were first introduced in the 17th century, they allowed a substantial amount of light into buildings. By the end of the 18th century, they were adapted to allow even more light into rooms, and bigger glazing panes started to be made. The result was a lighter look and windows that were more elegant.

The introduction of sash windows also necessitated an entirely new range of ironmongery. Early pulleys could be made out of wood. Later Victorian ones were made of brass or a mix of wood and leaded. There were also a variety of kinds of knobs and shutter hinges. The ironmongery pieces need to be cleaned and preserved to appreciate their beautiful design.

Timber windows require careful maintenance to keep them in good condition. Inattention to maintenance routinely could lead to:

Sashes that do not slide easily.

holes in the frame that admit water, which can cause damage and decay.

Water can penetrate the putty and cause decay to the frame or cill.

In the I920s and I930s steel casement windows grew in popularity due to their durability slim and affordable and were in line with the trend for healthy living. However, research has revealed that traditional softwood sash windows can be just as efficient in thermal efficiency as PVC-u double-glazed windows, and may be more appealing than the sleek lines of contemporary casement windows.

The industry of replacement windows was able to convince homeowners that their old windows were decayed and drafty. They were also beyond the budget for repair. Many old timber windows are repairable and can be used for many more years with minor repairs.

5. Maintenance

A traditional sash window needs regular maintenance and inspection. Failure to do this can lead to sash cords breaking, excessive wear on the glazing bars and the deterioration of putty and paint. The removal of the sashes may also cause structural shifts 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 the open position, which can let water and draughts enter the structure.

Moisture penetration is a common cause of damage to windows made of timber. This can be prevented by regular maintenance by thorough painting and eliminating the source of dampness. The paint can be removed to reveal the soft, decaying wood. The sections that are rotting should be carefully removed and the affected part should be scarfed together or glued together using replacements of the same type as the remaining timber. This method of repair increases the amount of original fabric that is left and is one of the least invasive methods of treating timber-to-timber decay.

A resin-based wood condenser is a viable alternative to traditional process of sanding or staining. It is brushed on the surface of the timber to stabilize it and shield it from further damage. It is particularly beneficial in the treatment of pulleys and sash cords which can help prevent the breakage.

It is important to restore and not replace any old ironmongery such as sash latches and stays. It is difficult to replace these items without altering their original design. It is also recommended that fittings made of aluminum like sashlifts, as well as chainstays, be avoided as they can cause corrosion and deterioration of timber frames and sashes.