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Basic Step by Step Repairing a Double Hung Window 

Today we went to look at a basic example of repairing of some timber sash windows in Newmarket.

We previously documented our lengthy revival and restoration processes on here before which has a much more robust and encompassing approach. However, we figured that people would like to see a basic repair in action.  

Let’s get into it. 

If you’re here, you might already know that single pane double hung timber windows don’t have a great reputation. Most are very old by now and have fallen into disrepair. Either they are rattling, draughty, discoloured, disfigured or all of the above. 

As we definitely know, with the right repairs, these windows can be restored and rival the effectiveness, glamour and energy efficiency as any window on the market. They still retain that classical charm too. 

For this example, we are going to assume the window is old beaten up, rattling and ugly. Everything is still there, all the parts, however everything is just a little broken and old. Opening the windows is hard. It looks bad. Flakey paint.... so we’ll do a complete but fast and affordable overhaul. No bespoke re-creations of frames to fit specific architrave’s using machinery. No. Just a restoration of what we have in front of us using minimal materials. 


 1. Remove the sashes 

Firstly, unscrew or remove the stops (usually decorative mouldings in front or lower sash). 

Then remove the lower sash and detach cords and other functionalities. 

Stop the cords from being moved into the weight pockets. 

Detach the parting bead to remove the upper sash, however that is attached. 


 2. Remove the glazing. 

Now we need to free the glazing being held by whichever putty compound the last window tradesman deployed. 

Heat it up with some sort of heat gun making sure to be safe. Pry the putty away with a putty knife. Find the exposed glaziers points and ease the glass out. 


 3. Sort the joints 

Now you need to clean the joints where the loss of functionality is occurring. 

The window is old and beaten up so it is likely that there is decay, rot and misshapenness of the joints. Grind away any of these imperfections as we can remould the joints to fit as they should. 


 4. Use epoxy

Now to recreate the joints so they are in the shape they should be. Rebuilt, strong, sturdy and ready to allow good functionality as they should. Firstly, apply a layer of epoxy primer and allow it to sit for 15 minutes. 

Next, mix both parts of the epoxy filler into a thick liquid type substance. We don’t want it to be watery but we also wanted to spread and set. Squeeze the substance into the joints and where are you reduced the timber. We are essentially trying to bring everything back to its original shape at least. That will be inevitable excess once the epoxy has tried, but that is OK because we can simply grind this away. 

Off the setting an appropriate amounts of the substance, leave everything to dry overnight and set properly. 


 5. Patience 

Although you probably want to get the job done, your brand new restored sashes, but we have to be patient. Wait an additional day for the epoxy see to fully set in.

Well done. It is a day later. Now you can sand the frame and inner portions using grit paper. Make sure to wipe down all the dust so that we have a clean finish. Now we need to see you and protect the wood. Use primer. If you do not use primer at this conjunction, The wood will fail in due course indefinitely. 

Great all of our timber is now primed and ready to go. 


 6. Back to the glass 

Lay your frame down on an even surface. Use glazing compound and press it into the rabbet at the pane opening. Press the pane into the compound gently until embedded correctly. 

Now add more of the compound alongside the edge of the glass between the sash and the glass. Do this to all panes in use. Allow this to sit for at least 4-7 days. Prime the putty once set. 

Now you can paint the sashes, frame and putty for aesthetics and practical purposes. A nice layer of protective coating. 


7. Hang the window 

Now is the time to add any draught proofing measures. Get the functionality smooth by either replacing the sash-cords or using a lubricated spray. Connect the cords back to the upper sash and secure with the parting beads. If these are beaten up, you could get a new set. Attach the cords to the lower part then put the stops back to secure everything in place. 

And there we go. A basic repair for a beaten up old window. Again, this assumes no splicing required, nothing to be remade to size, no remodelling the pieces to fit other levels of glazing.... just a basic fix. Strip everything back, reshape the wood, apply primers, get in the new essentials like cords and glazing, reattach everything and hang it back up. There are probably more detailed DIY guides out there, we just wanted to give you our take on what a basic, super standard, super cheap minimalistic repair would look like. It’s still going to take a few days, it’s still going to cost whoever in materials and workmanship and you can still make a window look fantastic without the added frills, most of the time. 

Sash Windows Cambridge Company

Cambridge, Cambridgeshire, United Kingdom.

Email: sashwindowscambridge@gmail.com

Mobile: 01223 320566