If you notice draughts or small leaks, it is probably time to check the rubber seals for glass in aluminium windows. In this guide, you will see what options are available, when to choose EPDM seals or PVC window profiles, how to measure the channel and glass correctly, and the basic installation to restore the seal without complications.
1. Types of seals for aluminium windows
1.1. Rubber seals for aluminium window glass
They provide a perimeter seal between the glass and the profile, improving thermal and acoustic insulation and reducing vibrations when closing.
1.2. PVC window profiles
A practical solution for quick replacements. They offer a good visual finish and are easy to install when not used intensively or indoors.
1.3. EPDM seals
Material with high resistance to UV rays, temperatures and cleaning products. Ideal for outdoor exposure and demanding climates.
1.4. Rubber profile manufacturers
At ISOGOM, we are rubber profile manufacturers, designing and extruding custom seals for short runs or continuous production, with technical advice and quality control. Check out our extrusion services.
2. How to choose the right size
A correct measurement ensures a uniform seal and prevents gaps. Note the actual thickness of the glass, the width and depth of the aluminium profile channel and the gap to be covered. With this information, you can decide on the optimum geometry and hardness for each window.
- Glass thickness: 6, 8 or 10 mm are the most common. The seal groove must fit tightly.
- Profile channel: check the width and depth to prevent the seal from coming out.
- Material: EPDM for outdoor use and high durability; PVC for indoor replacements.
- Hardness and geometry: choose Shore A and lip shape according to closing pressure and gap.
3. Step-by-step installation instructions
Prepare the area before you start. Clean the glass and profile thoroughly, dry completely and have a cutter, cloth, tape measure and isopropyl alcohol handy. Place the seal without stretching it, check the fit of the leaf and perform a quick test to ensure there are no gaps.
- Cleaning: remove dust, limescale and old sealant residue.
- Cut to size: make straight cuts and, if you reach a corner, make precise mitre cuts.
- Fitting: fit from one end without stretching the material.
- Check: open and close the window; it should not rub or come loose.
- Final test: check for leaks with a backlight or a little water.
4. Signs that the seal needs to be replaced
When the rubber hardens, cracks or turns white, air or water leaks appear, noise increases with the window apparently closed, or the sash loses its fit and vibrates, it should be replaced. If, even after cleaning and adjusting the fittings, leaks or condensation persist, a new seal will restore the watertightness and prolong the life of the window or door.
5. Common mistakes and how to avoid them
- Choosing a profile that is too soft or too short for the actual clearance.
- Installing with dirt or moisture, which reduces grip and service life.
- Stretching the seal during assembly; when it shrinks, it leaves gaps.
- Not checking compatibility with the aluminium profile channel.
Do you need a custom profile?
At ISOGOM, we manufacture specific seals and profiles for manufacturers and installers. Check out our processes and certificates in Quality and tell us about your case.
