Draught Proofing

On your marks.

Badly fitted, draughty windows can cause even more heat loss and discomfort than single glazed panes. Luckily, effective draught proofing is an easy DIY job, and we’re in the business of making things easy. With a bit of practice, draught proofing an entire sash window can take just a matter of minutes.

The best way to draught proof many windows is to use tape which, on the same side of the tape, is half self-adhesive and half non-adhesive. This allows the tape to be secured with the adhesive half while the non-adhesive half covers up any gaps without sticking, stopping the draught from passing through. As it’s translucent, the tape does not obstruct view. You can buy the necessary materials in our shop.

Get set.

The following guidelines are for wooden sash windows, but the process for other types of windows is very similar.

Generally, you need to draught proof three areas of a sash window:

  1. The centre rail where top and bottom (or left and right) sashes meet.
  2. The bottom of the bottom (BB) sash, and top of the top (TT) sash.
  3. The sides of the sashes.

Each needs to be draught proofed slightly differently.

The centre rail and the BB sash are usually the quickest and also the most important. Try doing these first and only do more if necessary.

Go.

Before you begin, it’s vitally important that you clean all relevant surfaces. Self-adhesive tapes hate dust and dirt and they also hate moisture, so before applying the tape, it is very important to:

  1. Clean relevant surfaces with a damp cloth.
  2. Dry thoroughly.
  3. Spray the surfaces with rubbing alcohol, which is very good at removing oily marks and dries without leaving a residue.
  4. Dry thoroughly once more, before leaving the surfaces for a few minutes so that any residual moisture evaporates.

Ideally, do all of this on a dry day, when there’s no chance of moisture condensing onto the surfaces the tape is going to stick to.

How to: where the sashes meet. 

These can be a major source of draughts, especially when the sashes aren’t closing together effectively. This area can also be very moist if panes suffer from condensation, which can stop the tape from sticking effectively. If you can, ensure you have installed a Gecko Pane first to reduce pane condensation.

  1. Clean as advised in the ‘Preparation’ section, paying particular attention to where the sash meets the frame at the sides, as these areas can be particularly dirty.
  2. Cut a length of tape for each side of the sash closer – cut them slightly longer than you need initially, then trim to the exact size.
  3. Stick the tape to the edge of the top sash, such that the non-adhesive side of the tape overlaps the bottom sash by around 5mm.
  4. Trim off any excess and repeat for the other side of the closer. 
  5. Press down firmly all along the tape, especially where it ends.
  6. Close the window.
  7. Keep it closed for 24 hours to give the adhesive time to bond.
  8. The next day, gently open the window by raising the bottom sash, then close it again to fold the non-adhesive tape between the two sashes, effectively sealing the gap.
Middle of closed window
Middle of closed window
End of middle of closed window close up

How to: bottom and top. 

  1. Starting with the bottom, open the window by raising the bottom sash. 
  2. Clean the horizontal bottom of the window frame (not the sash) as advised.
  3. Cut a length of tape slightly longer than the frame, then trim to the exact size.
  4. Stick the tape to the window frame so that the non-adhesive side overlaps the frame’s outward-facing edge by about 10mm.
  5. Trim off any excess tape. 
  6. Press down firmly all along the tape, especially where it ends.
  7. Close the window. 
  8. The protruding edge of the draught proof tape will become trapped, closing off any gaps. 
  9. Keep it closed for 24 hours to give the adhesive time to bond.

 

Afterwards, repeat the procedure for the top. The pictures below show that the bottom (and side) draught proofing tapes are unobtrusive once fitted.

End of the bottom of the window closeup
Middle of the bottom of the window

How to: sides (bottom sash).

  1. Clean every edge of the window frame where it meets the sash.
  2. Cut a length of tape slightly longer than the sash, then trim to the exact size.
  3. Starting at the top of the sash, stick the tape to the edge of the window frame so that the protruding edge of the tape is pressed against the sash, covering the gap between sash and frame. 
  4. Press down firmly all along the tape, especially where it ends.
  5. Close the window.
  6. Keep it closed for 24 hours to give the adhesive time to bond.
Bottom of window when closed
End of bottom sash edge
Bottom sash edge

How to: sides (top sash). 

  1. Top tip: The frame above the top sash is often curved, so you usually have to stick the draught-proofing tape to the sash, and not the frame.

    1. Clean every edge of the sash where it meets the window frame. 
    2. Cut a length of tape slightly longer than the sash, then trim to the exact size. 
    3. Starting at the top, stick the tape along the sides of the sash so that the protruding edge of the tape is pressed against the frame, covering the gap between sash and frame. You need to be careful that the tape doesn’t protrude too much, or it could lightly damage the bottom sash when you open the window. 
    4. Press down firmly all along the tape, especially where it ends.
    5. Close the window.
    6. Keep it closed for 24 hours to give the adhesive time to bond.
The end of the top edge
Edge of the top of the window