Retro fitted sashes:
Having spent over 20 years on site personally installing both products, I’ve had first-hand experience of the issues that arise when retro fitting sashes.
My advice to clients is to install new box sash windows.
After many years of retro fitting, in 2019 we finally decided to stop providing this product, although the finished retro fitted installations were to a high standard, some of the issues we were facing were arising far too often. I’m regularly asked ‘what’s the difference’ so, I have provided some details on why I recommend new box sash windows.
The benefits of retro fitting fall down to two things; the first and most popular is the cost, the retro fitting option is around 20% financially more beneficial than complete new windows, the other is the possible redecoration of internal walls. To note, the average cost to redecorate an internal wall should be between £60 to £100.
As mentioned, having personally been on site many years and having fitted over a thousand sashes to existing frames, there were many issues that would arise that I have detailed below:
Excessive repairs once the box frames were stripped down, some repairs can only be spotted once frames are stripped of old paint and sanded down. On occasions new sills would need to be installed and large frame repairs carried out, due to deep fermentation of dry or wet timber decay. It would always be very frustrating having to inform clients of an additional cost having already accepted an estimate.
Warped pully styles, sills and frame timbers, this can be an eyesore as the sashes have to be fitted bespoke to the frame. If a frame's sill has dropped one side by 15mm this can be quite evident once a sash has been fitted, this applies to both top and bottom sashes. Usually, the middle part of the frame (the centre horizontally) over time becomes the widest part of the frame, the width where the sill is will be the narrowest. This can cause a new sash to ‘judder’ when moved up and down, reducing a smooth action of motion and on severe occasions also difficult to draught proof.
Not being able to install a suitable thickness sash, a typical sash thicknesses will be 35mm, 40mm and 44mm, my opinion is that a 35mm thickness sash is far too thin for a sash. A 4mm x 6mm x 4mm glass unit would be applied to the sash, this can decrease thermal efficiency and also affect the operation of the sash as the draft exclusion brush also has to have enough room to operate efficiently.
The weights in the box frames are very important, they must move freely without interruption to help the sashes run smoothly. Issues can be weights getting caught inside old box frames, due to debris and nails from existing architraves penetrating through the frames. This interrupts the movement of the weights, you can often hear the weights scratching along these nails which is quite unpleasant. Another issue is the ‘wag tails’, these are the dividing timbers that separate the top and bottom weights inside the frames. These can be absent or broken, although these can be replaced it would be an additional cost and quite a task to install the new ones.
These are the cast iron wheels the sash cords operate on, they can be replaced with additional cost but complications can arise when a secure fitting cannot be achieved for the new pulleys. If the original pulleys are kept they can be noisy, and occasionally fray the sash cords due to the edges of the wheels being distorted, they can also rattle and screech, even lubrication cannot help on occasions.
Repainting a 120-year-old frame can cause issues with new paint not holding to the timber, sticking sashes, paint colour distortion, and generally getting a smooth finish. The main issue is the duration of the newly applied paint, this could need revisiting after two/ three years (depending on weathering), an additional cost to factor in with future maintenance.
Our new windows are draught proofed differently to refurbished ones, if you had the products side by side, the operation and aesthetics are noticeably in favour of a new box sash window. The new windows have a heritage style draught proofing system, nearly all the seals are hidden complimenting looks and fuss free, future maintenance. The exposed brushes the retro sashes are fitted with will discolour over time and make the windows particularly hard to repaint, these brushes can also slide out and deplete.
New windows are always installed level so eradicating unsightly subsidence is a nice factor to embrace, looking at a perfectly fitted window or door is a visual pleasantry and will compliment any room with uneven surfaced areas.
Existing box sash frames can have poorly applied external pointing, this is the sand and cement perimeter that surrounds the exterior of the frame. This can be an existing nuisance due to unsightly repairs, sections missing or being redone to a poor standard. This can also lead to direct water ingress damaging internal walls and also causing draughts. New box sash windows will come with new pointing, guaranteeing a water tight frame along with looking visually better.
Did you know retro fitted sashes do not have to meet building regulations, this means the newly fitted double glazed sashes may not conform to energy efficiency standards and do not need FENSA certification. All new windows and doors that have been completely renewed have to meet strict building regulations, this means you are guaranteed a superior product inside and out.
I hope this has helped with any questions you had, please feel free to email or call to discuss any further information you require.
