Windows

Frame

With the old render removed, now is the time to repair any windows that need it.

I'll start by removing the architraves and jamb extensions, clean out all the debris I find in the frame-to-stone gap. I'll retrieve the sash counter-weights as well if they've come loose.

Visible below the inside timber stool is the white block of limestone that is part of the exterior sill and showing all the chiselling marks. I'm thinking this should be left exposed.

At least two windows have majorish problems:

In one window the timber interior stool appears to have dropped a little at one end but, in fact, the whole frame is slightly lopsided and appears to have been this way forever. So this will be fixed but it will require removing and disassembling the entire window including the frame.

On another, which is the only one with a working sash, and the one I'm starting on, there's a gap on the outside of about 15mm at the top left corner between the limestone block cement filler and the frame (photo 41 below shows the corner with gap closed). It was fixed by cleaning out the gap, pushing the top frame corner out as far as possible and re-wedging the frame tight (photo 46 below).

This has exposed another problem with that window. The timber lintel is skewed and protrudes out from the plane of the wall at one end by 15mm (right-hand side of lintel photo 42 below). It has always been this way and the architrave head moulding had been cut (chopped) to taper at the back to allow for it. Simply putting things back as they were will cause problems when I re-render the wall flat, so I've added 15mm width to the side and head jamb extension to bring the architrave out 15mm.

I used strips of wood cut from one of the skirting boards that I removed from another room (photo 43 below) and is the same cedar as the existing jamb extensions. I will then attach a tapered strip of timber to the lintel to give the architrave moulding a flat backstop against the lintel and an edge and seal to render to. The stool has enough depth to take the extra 15mm width on the jamb extensions and will not look any different to the other window stools when finished. Once the wall is rendered there will be no gaps and the lintel will be rendered over and not be seen.

Now that I have a solution for the wonky lintel-to-trim interface for the first window and have prepared its jamb extensions for reinstallation, the next job before is to remove both sash, clean them up and open up the access to the counter weights, which have been painted over. The top sash had been painted closed and nailed in position through the horns.

Images 5 and 7 show the multitude of different colours used on the window.

The entire frame will be painted before the sash, beading etc. are replaced. Both sash will be painted before reinstalling. The sliding faces of the sash will be left bare.

Sash Repair

The easiest and quickest method I found to remove the old glazing putty is to use a multi-tool oscillating saw. Tried a heat gun but cracked too much glass, not from the heat but from the pressure applied removing the softened putty due to uneven support behind the glass where putty had fallen out.

These sash are in very good condition except for one muntin section where the fillet between the glazing rabbets was so damaged there was mostly only putty and no wood.

I decided to cut the whole fillet away back to a flat face, cut a 5mm deep centre slot using a sharp knife and glue a new strip of matching wood to create a new fillet. This worked very well - photos 19 to 21 below.

Reassembling the [first] repaired window

All beads were painted separately prior to reassembly.

New sash cords were installed during reassembly following a method that feeds the cord through all four pulleys before cutting to length.

Starting by feeding the cord in through the outer left pulley down to the weight access opening then across to the next pulley in the order: left outer, right outer, left inner, right inner. Then start cutting the cord to length and attaching the weights for the outer sash: left then right. Pull the weights up as far they will go and clamp the cords at the pulleys then attach the cords to the sash as it sits vertically on the sill. There should be minimal slack in the cord. Once fixed, carefully remove the clamps and gently let the weights take any slack. Position the sash in place and check that it has full travel up and down.

At this point the parting beads normally go in but because I have a single access panel on each side that the parting bead runs through I needed to attach the inner weights and fit the access panel before I could replace the side parting beads. Now attach the cords to the inner sash and check for travel.

Finally reattach the interior staff beading.

This method of threading the cord requires attaching a weighted "mouse" only once to the cord at the start and therefore saves some time. In my case I had removed all four pulleys and was able to drop the cord down and out the weight access opening without the "mouse". I also have a single access opening for the two weights on each side and no internal parting slip panel to separate the weights, which simplifies things but just needed to be sure the cords weren't wrapping around each other inside the weights pocket.

Both sash were a very loose fit so draught seals were fitted to the running edges of both sash before final positioning (Raven RP61 - woven pile strip). The seals were fitted toward the outside (of the cords) on the upper sash and toward the inside (of the cords) on the lower sash to avoid having them run across the weights access panel on each side, only because I felt it might otherwise increase wear and reduce the effective life of the seals.

The colour scheme for the windows is "Wheat" on the exterior and white inside but I've decided to leave some parts "Wheat" even though they are visible from inside. They would normally be painted half and half depending on which parts are visible with the windows closed. When the time comes to repaint I disassemble the window again because it's easier overall and the end result looks better.

The jamb extensions originally had been nailed to the box frame so this time I've used screws that will be hidden once the archtrave goes on. This is consistent with the philosophy of allowing for easy disassembly and reassembly during maintenance. Starting with the head jamb extension I used an auger bit to drill two deep pocket holes (about 120mm) at the interior-facing edge through the width of the panel (about 150mm) to take a screw the rest of the way into the top of the box frame. The side panels were then fitted and screwed at about 45 degrees through the interior-facing edge at the top into the head jamb extension and at the bottom to the stool. The architrave will be brad nailed to these edges to hide the screws and the holes.

Similarly, I've used screws instead of nails to fix the frame wedges in place. With expansion and contraction cycles and vibration etc the wedges can come loose and the frame can shift, as it did in the past to open up a 15mm gap (image 1). However, rather than screw through the wedges, all that is needed is to drive a course-threaded screw between the wedge and the lintel as in the images below. If they do come loose it will be possible to tighten the wedges and the screws without removing the jamb extensions, just remove the architrave.