Double-glazed windows are much more efficient than single-pane windows. In a double-glazed unit, air trapped within the panes provides better thermal and sound insulation between the exterior and interior sides of the window. When retrofitting an existing unit, consider some of these tips for the homemade double glazing project. Use only high-quality acrylic glass, have the glass cut at the home improvement center, use adhesive magnetic tape for securing the two panes of glass together, place the magnetic tape onto the panes, and keep the glass extremely clean during the installation process. For best results with this type of DIY double glazing job, install the secondary pane on the interior side of the window.
Select a very high-quality acrylic glass for the secondary pane, as this type of glass is very similar to traditional glass but is shatterproof. The material is also more lightweight, an important aspect for larger windows. If the existing window has latches or handles, the new pane should be the exact same size as the existing pane. Skip the arduous DIY double glazing task of cutting the glass and have the glass cut at the home improvement center instead. The center has the proper tools, making the cuts more precise and the edges more polished.
The most important benefit of DIY double glazing windows is added thermal insulation. Therefore the seal between the two panes must be airtight. Magnetic strips provide an excellent seal, but any gaps between the seams where the tape is applied is a possible air leak. Carefully measure, cut and apply the magnetic tape, and press the seams tightly together. This will reduce the air leakage and accompanying thermal insulation loss.
Both glass panes must be exceptionally clean before the seal is made. Keep the secondary acrylic glass pane covered in its paper or plastic wrapping until installation, to prevent fingerprints, dust and other debris from contaminating the surface. The primary pane should be cleansed thoroughly with a non-streak window glass cleaner or acceptable substitute. Avoid touching the glass, as fingerprints will show through the panes.
Finally, with this method of DIY double glazing it is best to install the secondary pane on the interior side of the existing window. This will prevent the glass from exposure to the brutal outdoor elements and moisture. If placed on the exterior side, moisture and debris will build up between the two panes, corrupting the seal and eliminating any thermal and sound insulation from the window.