Sash windows operate on a pulley system. The sash windows we build and install consist of various parts that all go towards the one of a kind design of these beautiful windows. Your typical sash window consists of a sill, timber linings, top and bottom rails, sash weights, and courts. When all of these factors work in accordance, the sash window will be able to move and function at its highest efficiency.
But the question remains, how do sash windows work? Each window is made up of two window frames, these are otherwise known as sashes, and they are both held up by a court. The court from each frame passes through a pulley system with a heavyweight on the other end that allows each of the frames to be opened and closed independently.
How sash windows operate is not immediately obvious
Sash windows have intricate mechanisms that allow them to work in such a way that provides full functionality, but this operation is pretty obscure. For instance, the counterweight is a steel, cast iron or lead sash weight and it is connected to the window by a sash cord. This cord runs over the pulley and along the top rail, and it is hidden in the frame so that it is not easily visible to the human eye. The pulley system of sash windows is hidden in the frames so homeowners can enjoy the look and beauty of their windows without the distraction of the mechanisms.
High functioning traditional sash windows
Traditional timber sash windows work very seamlessly with a weight and cord system. The cord that runs over the hidden pulley is connected to the window sash. The opposing balance created between the weight and the sash window allows enough resistance for smooth window opening and closing.
Sash windows can have intricate hinge systems attached that allow the window to be locked on one side while on the opposing side the counterbalance weight can be detached. This feature allows your window to be opened, whether it’s to enter or exit, to clean, or to allow fresh air into your home.
The importance and benefit of traditional window sills
A vital design element of many sash windows is the traditional sill at the base of each window. This sill is inside the base of each sash window to make sure that rainwater will drain away from the window. Traditional window sills are such an important element for sash windows because they prevent rainwater from building up within the frame, this can lead to extreme issues of rot as time passes.
How do sash windows work? These are the terms you need to know
- The top rail: This is the top horizontal frame of your window.
- The sash cord: This is the aspect that runs over the pulley wheel and suspends the weights. When it is time to replace the sash cord, it can be bought in roles (waxed sashes are optimal).
- Weight pocket: The timber linings on either side of the window create pockets where the weights hang.
- Parting bead: This is a thing, long sill that fits the box frame to make different channels for the upper and lower sashes to align in. It also assists in keeping the top sash stable.
- Meeting rails: The horizontal framing elements which connect the two sashes together in the middle.
- The horizontal sill: This is a board that fits horizontally across the inside base of the sashes and it is shaped in a way that allows water to flow away from the window to avoid rotting and leaking.
- Weight: Two lead weights hang on either side of the sash cord to allow counterbalance each of the sliding sashes.
- Timber lining: These are the parts that create the casings of the box frame. They are hollow so the weights can fit inside them.
- Pulley wheel: A pulley that sits in the top of the pulley lining so the sash cord may be able to pass over it and counterbalance the weights.
How do sash windows work and how are they different to box sash windows?
It is often confusing for many people when they hear the term sash windows and the term box sash windows. In the US these windows are usually quite different, however, in the UK these terms are usually used interchangeably to describe the same thing. In the past, or traditionally, box sash windows were heavier than sash windows and they were very popular in most homes. Now both terms are used interchangeably in the sash window industry, so they work in the exact same way!
An efficient sash window requires professional fitting
Sash windows operate at their highest efficiency when they have been built and installed by industry professionals who are qualified and have experience in both the sash window and double glazing industries. From all of our aforementioned points, we know that sash windows operate with an intricate pulley and weight system, so it is vital that they are installed properly to allow for maximum security, efficiency, and functionality.