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Timber Sliding Sash Windows

To appeal to customers of all property types and ages, your product line needs to include timber sash windows. Our timber sash windows are available with a spiral balance mechanism or traditional weights & pulleys.
  • Choice of sliding mechanisms to suit all properties
  • Effective locking mechanisms supplied
  • Range of cill, frame thickness, finish and ironmongery options
  • Choice of timber sashes and wood species
  • Endurance and salt spray tested
  • Drained and ventilated system with sloped rebates
Painted timber sash window supplied for installation
Timber sash window with cross halved astragal bar
Timber sliding box sash window with horn
Sliding sash window with gold hardware
Traditional sash window with modern spiral balance mechanism
An internal view of a timber vertical slider supplied for new build
Timber sash windows
Timber window with weights and pulleys mechanism
Sash window supplied for installation
A traditional style property with timber sash windows

Tap into the heritage and new build property markets

To be able to appeal to customers of all property types and ages, your product line needs to include timber sash windows. Our sliding sash windows are a classic choice for homeowners who want to maintain a heritage feel in their property. We offer two sliding mechanisms including a traditional weights and pulleys mechanism and a modern spiral balance system to appeal to any homeowner.

Why choose Dempsey Dyer’s trade supply service for timber sash windows?

  • Four timber species – Accoya, Sapele, European Oak, European Redwood
  • Effective locking mechanisms supplied
  • Available with traditional weights & pulleys or spiral balances
  • Capable of achieving a whole frame U-value of 1.3 with 24mm glass unit
  • Tested to BS6375 part 1 (2009) with an exposure category of 2000+
  • Opening can be restricted to 100mm
  • Optional tilt facility with sashes capable of tilting inwards between 40-45° (Spiral balance mechanism)
  • Highly resistant against corrosion

Timber Species

Entice end users with options for timber species

Whichever species of timber you and your clients prefer for your timber casement supply, we use only the most innovative materials – and those that offer style and function.

Accoya timber species


Accoya is a high performance, modified timber made from sustainably sourced softwood. Its durability is labelled as ‘Class 1’, the highest level of durability for timber. This species is suitable for both windows and doors.
Read more about Accoya

Sapele timber species


Suitable for both windows and doors, Sapele is a common hardwood sourced from West Africa and the Cameroon, Sapele achieves a ‘Class 3’ durability classification, making it ‘moderately durable’.

European Oak timber species

European Oak

European Oak features an attractive grain and we source this through an FSC (Forest Stewardship Council) This species has a ‘Class 2’ durability classification and is suitable for both windows and doors.

European redwood timber species

European Redwood

Sourced as engineered laminated stock to improve durability, this species is a cost- effective option for stylish new timber windows.

Sash Styles

Meet conservation requirements with four sash options

Not only do we offer one of the broadest timber product ranges in the industry, we also provide aesthetic choices in terms of sash design. With four unique and innovative sash options, clients are able to meet specifications and choose a design that also meets their personal needs.

They all are based around the traditional timber design of ‘putty-line’ external and ‘ovolo’ internal mouldings. This ensures that you can pass on flexibility with our timber casement supply.

To further replicate the appearance of traditional timber sash windows, we can fit astragal bars and leaded glass. We can match the leaded design to an existing pattern or provide a range of classic options such as the diamond style.

Mayfield: 24mm IGU

Mayfield: 24mm IGU

Mayfield’s modern design is available with or without astragal bars, and in conjunction with the astragal bar option an interbar creates the appearance of single glazing.

Amberley: 20mm IGU

Amberley: 20mm IGU

The moulding on Amberley is based on traditional timber putty-line external and internal moulding details. This style is available with or without astragal bars.

Petworth: 16mm IGU

Petworth: 16mm IGU

As energy efficient as a 24mm unit, Petworth is a double glazed sash which gives the appearance of single glazing.Petworth: 16mm IGU
As energy ef cient as a 24mm unit, Petworth is a double glazed sash which gives the appearance of single glazing.

Ebernoe: 4-10mm

Ebernoe: 4-10mm Single Glazed

Ebernoe is ideal for conservation areas where maintaining original aesthetics is extremely important as it uses traditional putty glazing techniques.


Sash window mechanisms to suit properties old and new

Our available sash window mechanisms allow you to provide a product suitable for a range of properties from old to new. Our sliding sash windows with spiral balances are highly durable, perfectly suited for the new build market as it does not require the deep reveals that are needed on the traditional box sash. If you are replacing old timber sliding sash windows our system incorporating weights and pulleys is ideal as it has been designed to replicate traditional timber vertical sliders with as much accuracy as possible.

Timber sliding sash window with spiral balance

Spiral balances

A hybrid of traditional appearance with modern technology; this option suits newer homes as it doesn’t require the deep reveals that a weights and pulley system needs. Tested to 10,000 cycles with extra options including; lockable fitch fasteners, sash rings, D handles, lockable restrictors and an optional tilt feature.

Timber sliding sash window with weights and pulleys lift mechanism

Weights & pulleys

A perfect replacement for original timber windows, these are manufactured to resemble the traditional system as much as possible. A facility to restrict the opening to 100mm is available along with optional internal horns, dry gasket glazing rebates.


Coloured windows and doorsChartwell green colour timber conservatoryPreserve and protect with colour

Our timber products are available in a range of translucent and opaque finishes. We offer most colour options but we have our own standard colour range. Colours may appear slightly different on the various species of wood so we would recommend requesting a sample.

Translucent finishes preserve the natural beauty of your timber windows while opaque resembles the traditional colouring of the past.

With opaque finishes, all RAL colours are available, giving an almost unlimited choice when it comes to personalising or matching to existing windows.

Our paint system also protects the wood from harmful ultra-violet rays and from water ingress thanks to it’s microporous structure, which allows excess moisture to escape. Our paint is also flexible meaning it can expand and contract naturally with the timber.


Efficient and Effective Glazing

All of our windows come with high performance glazing that effectively prevents heat from leaving but also allows in a comfortable amount of natural light.

With a range of efficient glazing options, an existing pattern can be matched. They can also be an attractive way to maintain privacy. With varying degrees of obscurity, natural light can still enter the room.


Personalise with traditional hardware

Our sliding sash windows, come complete with a deep bottom rail, run-through sash horns as well as choice of other features and hardware to complement any home. From PAS24 espagnolettes to shootbolts, all our locks offer security as well as style.

Durability by Design

A member of our skilled timber window manufacturing teamA timber window being manufactured ready to be supplied to the installerProfessional design and finishing process

To ensure you’re getting the best products, our timber range of windows and doors are designed with sustainability and durability in mind. We have full control from start to finish to create beautiful timber products every time. Our timber has exceptional performance due to a minimum 7” slope which ensures water runs off easily. Any moisture easily drains out due to the ventilation and drainage beads present in all bottom glazing rebates.

We only source timber with a low moisture content which prevents movement and micro porous paint ensures a high-quality finish while still letting the timber breathe; ensuring the longevity of our timber products. All the critical joints have a v-joint sealant which ensures further protection from moisture.

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Download Centre

If you want to know more about our products, processes and accreditations, fortunately we offer a range of downloads. Download a range of literature free of charge, to refer to in your own time.

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Installers and other businesses can only work effectively if they have a reliable trade supply service – offering the highest performing products. Luckily, here at Dempsey Dyer we only supply the latest options from market leaders. This guarantees quality, performance and durability – regardless of the product choice.

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