window improvement services

It is important to remember that we don’t just offer replacement. As strong advocates of conservation where possible, we are delighted to offer a range of services designed around preservation of your existing windows and doors.

There are several factors that will determine the condition of your traditional timber windows.


At the outset, the materials used in the construction of a window will play a major part in their longevity. You may be surprised to learn that a large proportion of the windows that we have to completely replace are less than 30 years old as the use of inappropriate timber species leads to a lack of product durability. For further information on timber species please review the Timber Species Database available from TRADA.


Windows on south and west elevations are subject to an increased level of exposure. With heating from the sun and wetting from rain comes shrinking and swelling of timber, which invariably results in splitting of the paint film. Cracked paint may allow moisture into the timber and start a process of deterioration. Proximity to the coast and therefore salt content within the air also has a significant effect on the weather of painted timber. Our warranty summary will give you an overview of how the performance of coatings may vary with differing site exposure.


As the painted surface of a timber window breaks down, it is important to remove the old paint layers to promote adhesion and good performance from the new coating. Windows left without paint on and those that are redecorated without appropriate preparation will deteriorate.

It is well understood that with appropriate decoration (and therefore protection) timber products will last indefinitely. So there is every chance that a 150 year window can last for a further 150 years! Not something that modern plastics can offer.

Draught sealing, mechanical overhaul and on-site repairs

In many cases we can improve the performance of your windows through a simple overhaul process. Traditional windows and doors will typically allow cold air, noise and dirt to enter your home through significant gaps at the perimeter (even if they are not noticeable). We can offer draught sealing services for sliding sash windows, casement windows and doors.

  • Eliminate rattles and draughts
  • Trap dirt on the outside
  • Improve the fit and operation
  • Offer minor timber and glazing repairs
  • Extend the life of the window

For sliding sash windows, the process would typically include the following:

  • Remove cords, beading, weights, top and bottom sashes
  • Planing both sashes to improve fit as required
  • Machine routing each sash and insert nylon pile and compression seal
  • Replacing all sash cords with pre stretched wax cotton cord
  • Undertake repairs to glazing and timber as described
  • Lubricating pulley wheels and use make weights to correctly counter balance sashes
  • Replacing staff and parting beads with brush pile inserted
  • Fill and caulk as required, paint exposed wood with primer leaving decoration ready
  • Replace or realign window furniture as agreed


Where the condition of the window requires more detailed repairs than our on-site draught sealing and overhaul process will permit, we offer a back to base option for complete restoration. This process would typically include:

  • Removal of window from frame, insertion of a suitable temporary board or glazing
  • Transport to our workshops and heat strip paint to assess level of damage and rot to timbers
  • Removal of glass or putty repairs and replacement of damaged or rotten timber to sashes and frame
  • Fill, sand and decorate sashes and frame
  • Replace or repair items of ironmongery
  • Return to your property and re-fit windows including introduction of draught sealing

This process should only be undertaken by experts given the rare and fragile nature of these products. We have an enviable track record in undertaking this type of work for some very large and complex projects running to hundreds of windows.


Callaghan Sash Windows has developed a simple product to enable the smooth motion of (particularly large) sashes. Where there is a little movement of the sash within the frame it is common to see a little rocking of the sashes and this can lead to poor fitting or even jamming of the sashes. This leads to issues with the decoration and operation of the window.

Sashmasta (patent pending) consists of a spring loaded nylon roller that helps to locate and move the sash smoothly up and down in the frame. This can be supplied with new windows or retro fitted into the sash. It will never be seen once installed – but you’ll be glad that it’s there.

Sashmasta can be used on sliding sash windows in conjunction with our new product and window improvement services.

Sash window reactivation

We encounter many instances where sash windows have previously been removed to make way for PVC or aluminium windows. In many instances the frame remains within its original opening and it is possible to introduce new pulleys and sliding sashes, complete with our draught sealing system. Please note that it is not always possible to do this and we would need to assess feasibility before further discussing this option.


As a company that prides itself on offering turnkey solutions we are pleased to offer decoration services in association with our other site based services. This is a sensible option to consider as we see many examples where decorators have painted over the completed draught sealing system, often dramatically reducing its performance.

In the case of sliding sash windows, we carry out all preparation with the sashes out of the frame and install the draught seals when painting is complete. In this way we can guarantee the efficient operation of your windows

Small building works

Occasionally it is necessary to undertake small alterations to your building to allow us to complete our work. We are able to offer a range of building services that can remove the frustration of trying to coordinate multiple tradesmen to complete works, examples include:

  • Supply of scaffolding and access equipment
  • Creation of reveals for doors or windows and installation of suitable lintels
  • Installation of masonry sub cills
  • Groundworks, Brick and block work for bays
  • Leadwork and roof tiling
  • Plastering and decoration
  • Removal and replacement or re-siting of taps and radiators

Steel window services

If your project also involves steel windows, we have an association with one of the UK’s leading specialist restorers and replacers of metal windows. We can offer a single point of contact with associated project management services

Planning consultancy

Through our years of working on complex projects in the UK and Ireland for a range of property types and status we have developed a portfolio of expert service providers that can offer a range of services on your behalf. These include:

  • Historic window consultancy
  • Drawing services
  • Planning, Conservation and listed building planning applications
  • Structural calculations
  • Building control compliance
  • Project management services

We can advise which services would be appropriate and if required, can include these as part of a package.

We will always give a detailed written estimate before you are committed to take any of our products or services.

Window improvement planning consultancy