Renovating Sash Windows

Well, four years after moving in, I cannot procrastinate any longer: I have started to renovate the sash windows at last.

The house has seven old sash windows (as well as the new double sash in the kitchen and the replacement Venetian window in the lounge, both fitted in 2011), most of which have old wavy glass.  Four are standard two over two, two are a pair of one over one in the bathroom (but they are totally separate windows) and the final one is our bedroom window at the front of the house (photo right): it is basically a normal two over two but each glass has an extra narrow pane on its outside, so there are two normal size panes and two narrow ones in each sash - eight bits of glass in all. Being a cautious sort, I wanted to start with a standard one at the back of the house but t'other half wanted me first to address the tatty complicated one at the front.  The thick paint was flaking and was missing two sash cords, the glass was barely attached and the cill was rotting, not to mention the catch which was rusted solid and loosely attached.

So, first thing on Monday last week, after much research and some advance purchases, and with a fairly favourable weather forecast, the lower sash was removed.  Basically, the process with each sash was to remove the glass (carefully!), completely remove all paint

and old putty, do any necessary repairs, prime, refit the glass and finally finish the painting.  Concurrently, the window frame itself needed a complete strip, replacement of four worn brass pullies (pulleys?), four new sash cords and new parting beads, not to mention some major woodwork repairs.  Looking at the photo (left), it reminded me of having a missing tooth for two weeks - too late to go back now!

The lower sash had loose tenons at the bottom corners, not to mention three loose glazing bars, and so needed re-gluing.  The photo right shows its condition after removing the glass and doing a fair bit of stripping.  One of the narrow panes had been cracked when we bought the house, and I had kept an old piece of wavy glass for just that job - it just needed cutting down.  The rest of the job was some hours of stripping, scraping and sanding, plus a small amount of extra gluing.

The upper sash came out on Tuesday morning.  This one had never fitted properly, and the reason for this was immediately apparent as the weights rested on the bottom while the

window was an inch from the top.  It also had a nasty steel bracket holding the centre glazing bar to the bottom cross member - sadly it wasn't in the right position and there was a 7mm gap to the lower bar.  That one I had already decided to do with some stuff called "Repair Care Dry Flex 4"; this is designed specially for things like doing structural repairs to window frames and isn't cheap - but it does the job admirably (the yellow green bits in the photo left)!

I managed to remove all seven unbroken pieces of glass from both sashes without further breakage - the eighth piece was already cracked when we bought the house and I had kept some old glass from the old lounge window as a replacement.  I also decided to use "Repair Care Dry Seal" instead of linseed putty; this is permanently elastic and seems a better bet after my poor efforts at using proper putty a few years ago!

I thought I had a good idea of how long all this work would take but, once again, I underestimated and it was not until Wednesday of this week (nine days after starting) that I 

was able to fit the freshly painted and glazed sashes back in place (right, before glazing).  I reckon it was over 40 manhours of work as well.  Everything went to plan except that it all took longer; even the weather was kind and no rain got onto my south facing work site until I was refitting the sashes.  I did break one of the narrow pieces whilst cleaning it but, fortunately, I had kept TWO pices from the old lounge window!  The only other issue, at the last minute, was a nasty splinter in the index finger of my right hand, due to careless sanding.

There was also the small matter of the window cill, which was oak but suffering from rot. 

I took off all the poor wood and covered the whole thing in Dry Flex, leaving a gap underneath for some sealant.  At the left bottom corner the sash frame had rotted and so this also received the Dry Flex treatment.  I slaved in a new bottom piece for the front frame, plus some bits for the cross member, both visible in the photo left.  The parting bead is also visible but this is simply a press fit (well, block and mallet).

So, I need to finish off various bits of detail like sealing around the frame and doing the black top coat, but the (almost) finished result has already attracted positive comment from friends, who say that it looks better than the similar window next door (restored three years ago by V******a).  I'll post a completed picture soon.