After removing the fixed sidelights, it also became clear the Mullion was also kept damp and had started to rot into the sill.

We began be replacing the tenons of the mullions and jams.

Next, we moved onto the side lights and doors themselves. After ensuring everything opened and closed correctly, we re-puttied were necessary before giving everything a coat of breathable primer.

An honorable mention goes to the owners of the property who kept us fueled with a fine selection of biscuits! For those who haven’t tried the traditional way of enjoying a TimTam, you don’t know what you’re missing!

To replace the sill requires 7 precise measurements to be taken in a very specific way. A new sill can then be made which will fit perfectly. We opted for Accoya acetylated pine for this sill, for its dimensional stability and supreme 50+ year rot resistance.

With the new sill in place, we check the sashes open and close perfectly.

We removed the sill from the previous repair which had been glued and screwed in place. The previous repair re-used the original oak sill but the frame behind had rotten to the point where it would no longer support the sill. The oak sill was still in great condition, so we tidied it up to re-fit later.

We traced the rotten timber up the frame to good timber so that we could form joints for the repairs that would be carried out in Accoya. Using most of the clamps we had, the glue up for this job was worth a photo.

While the glue set, we go to work on the sashes, repairing the bottom rails and stiles and re-glazing and puttying where needed.

We try to identify the root cause of rot to windows where possible. In this case, the home owner had already identified and fixed a leaking gutter joint and had also noted the wooden lintel above the window was allowing rain into the brick work. We finished the window repairs by forming an Accoya drip the would keep rain off the timber lintel and help direct driving rain away from the window beneath.

We’d like to start this post by thanking the homeowners for giving us the opportunity to work on this window. We regularly get to work on historic and unique pieces of joinery but not very often is it as challenging and requiring of an owner’s trust as this example.

Curves present a challenge to the joiner in that in order to join the curves, you need to be able to cut repeatably and accurately using machinery designed to cut straight lines. To carry out a repair, you also need to consider the inevitable settlement and wear and tear of the 100+ year old windows.

We started this repair with an investigation of the design, assembly and condition. Almost every cut needs some sort of jig, fixture or modification making so setting out the exact scope of the work helps keep control of the budget.

We identified some areas of the sill that didn’t need replacing as their condition was excellent. We also settled on a plan for repairing the sashes and sections of sill that did need attention.

The main reason the cladding hadn’t weathered too well was down to material choice. Joinery-standard untreated softwood hadn’t stood up to weather, despite its quality. We opted for Tricoya; an Accoya sheet material with similar rot-resistant properties, that makes it ideal for this type of application.

Another area we could improve on was the fixing method. Fixed using galvanised ring shank nails, the cladding was solid enough, but when being fired through a nailgun, the galvanising is often stripped off allowing rust to develop on the nail and eventually appearing on the outer surface , cracking the paintwork. We opted for specific stainless steel fixings to prevent this happening in future.

Lastly, any exposed end grain is vulnerable to weather. We built the replacement cladding like a cabinet, carefully mitering the corners and using floating tenons were necessary to ensure perfect alignment.

Most of this was done on the ground but to ensure a perfect fit, we wanted to make the final cuts for each dormer on the  access tower. Finding space for tools, materials and ourselves on a small mobile access tower was going to be a challenge. We also wanted to achieve good accuracy in the final fit. We turned to a handy solution in the form of the Mafell KSS series of saws which proved more than capable of producing the cut quality and accuracy we needed whilst taking up minimal space on the tower.

The glass was original to these 1920s windows and was manufactured using the drawing process which gives the tell-tale vertical ripples in the reflection. As the rest of the glass was original too, using float glass for the replacements would have been quite obvious so we sourced some drawn glass, which is still manufactured in France and Germany.

The putty, being 100 years old or so, had dried to a hard layer, firmly attached to the rebate of the sash. We have a number of different methods to quickly remove old putty without damaging the timber of the sash. This ensures the new glass gets a good bed of new putty and enough depth on the face.

With some master bricklayers on the case with the wall, we were given the task of repairing the porch. Made from a mix of oak and elm rounds, the original would have been made using the scribe rule method to align the joinery.

We wanted to keep as much of the original timber as possible so we set about repairing the joints which had snapped in the accident.

Templates were employed to give the correct orientation and alignment for the tenons. After that, it was just a case of blending the existing into the original a little more before reassembling on site.

With the surrounding lead work on the roof, it was a tight spot to get into but with sharp chisels and a practiced hand we were able to clear away the rotten timber to good wood and form a joint.

Using Accoya for the replacement means the owners won’t experience the same issues in years to come.

The first stage of repairs here was to focus on the small, simple repairs to part of the door lining, before moving onto the more structural elements of the construction.

We could then turn our attention to the rotten packing inside the web of the steel lintel. This was done the same way it would be done today on a new build, with the timber driven into the web of the steel to provide fixing points for a finish covering. We chose to change the orientation of the packing: firstly, to give more options for fixing but also to avoid the need to forcibly drive the timber into the web and risk disturbing the masonry.