Replacement Window Questions from Home Owners
Time for Replacement Windows?
Homeowners often come to us with questions about their double glazing. Here are some of the most frequently asked:
Welcome to Glasscraft’s FAQ page, designed to assist homeowners with understanding their sealed glass units and recognising when they do and do not need replacement windows. Glasscraft specialises in manufacturing high-quality sealed glass units and deals directly with the window trade. Whether you’re encountering issues with the glass in your double glazing or seeking guidance on window replacement, our FAQs provide valuable insights to help you make informed decisions about your home’s glass solutions.
Should you have any further questions, in the first instance please contact the tradesman or company that you purchased your windows from.
A: No, your new windows are not faulty. In fact, the condensation on the outside is a positive sign that your windows are working efficiently to prevent heat loss. Here’s why:
1. Indication of Excellent Insulation: Condensation forms on the exterior of the window when the outer pane is cold and the humidity outside is high. This happens because your windows are well-insulated. The insulating properties of the glass prevent heat from inside your home from reaching the outer pane, keeping it cool. This is a sign that your windows are effectively minimising heat transfer, maintaining the warmth inside your home.
2. Seasonal and Short-Term Occurrence: Exterior condensation is a natural phenomenon that typically occurs during certain times of the year, such as early spring and autumn. It usually happens when the outside temperature drops at night and the humidity levels are high, leading to the formation of dew on surfaces that lose heat rapidly, such as your well-insulated windows. This type of condensation is usually temporary and will dissipate as the temperature changes throughout the day.
3. Energy Efficiency Benefits: The presence of exterior condensation highlights the energy efficiency of your windows. By preventing heat from escaping, your windows reduce the need for excessive heating, leading to lower energy bills and a more comfortable living environment. This is particularly beneficial in the colder months when maintaining indoor warmth is crucial.
4. Difference from Interior Condensation: It’s important to differentiate between condensation on the outside and inside of your windows. Interior condensation can indicate excess humidity within your home and may require measures such as improved ventilation or dehumidification. However, exterior condensation, as described, is a normal and expected outcome of well-functioning, energy-efficient windows.
5. Enhancing Window Performance: To further reduce the occurrence of exterior condensation, you can ensure that your windows are kept clean, as dirt and debris can affect how moisture interacts with the surface. Additionally, maintaining proper air circulation around your windows by trimming nearby plants or trees can help.
A: The marks you are noticing are most likely related to the low-emissivity (low-e) coating on your glass. Here’s a detailed explanation:
1. Low-E Coating Reflection: The low-e coating on your glass is designed to improve energy efficiency by reflecting heat and ultraviolet rays while allowing natural light to pass through. When sunlight hits the glass at certain angles, the low-e coating can reflect light in a way that makes these marks more visible. These reflections are more pronounced under direct sunlight and may vary in appearance throughout the day as the sun’s position changes.
2. Normal Phenomenon: It’s important to understand that these marks are a normal characteristic of low-e glass. They are not defects but rather a result of the coating interacting with sunlight. When the sun isn’t shining directly on the glass, these marks often become invisible or much less noticeable, blending seamlessly with the clear appearance of the glass.
3. Processing Marks: In addition to reflections from the low-e coating, the marks you see could also be processing marks from the manufacturing of the glass. These marks are typically microscopic and not visible under standard lighting conditions. However, under specific lighting, such as direct sunlight, these marks can become more apparent. This phenomenon is common and does not affect the performance or durability of the glass.
4. Variability Throughout the Day: The visibility of these marks will fluctuate as the sun moves across the sky. In the morning and late afternoon, when the sun’s angle is lower, you might notice these marks more than during midday when the sun is directly overhead. This variability is a normal part of how light interacts with the low-e coating and glass surface.
5. No Cause for Concern: These marks do not indicate any problem with your glass. They are a natural result of the advanced coatings applied to enhance energy efficiency and comfort in your home. The primary purpose of the low-e coating is to provide better insulation, reduce energy costs, and improve the overall performance of your windows.
A: The choice between triple glazing and double glazing depends on several factors, including your specific needs, climate, and budget. Here’s a detailed explanation to help you make an informed decision:
1. Understanding Triple Glazing: Triple glazing consists of three panes of glass separated by gas-filled cavities, typically argon, which provides better insulation than air. This setup can significantly improve energy efficiency, reduce heat loss, and enhance sound insulation.
2. Specifying the Right Glazing: To maximize the benefits of triple glazing, it’s crucial to specify the right glazing makeup. A common and effective configuration is:
- 4mm Clear Glass
- 8mm Argon Gas Gap
- 4mm Low-E (Low Emissivity) Glass
- 8mm Argon Gas Gap
- 4mm Low-E Glass
This specific arrangement ensures optimal insulation and performance. However, in a standard 28mm glass unit thickness (which is common in the industry), the improvement over double glazing is only marginal.
3. Comparing with Double Glazing: Standard double glazing typically consists of two panes of glass separated by a gap filled with air or argon gas. While double glazing offers good insulation, triple glazing can provide additional benefits, but the extent of these benefits depends on the unit’s overall thickness and composition.
4. Importance of Unit Thickness: For triple glazing to offer a substantial improvement over double glazing, the units need to be wider than the industry-standard 28mm. Increasing the unit thickness to a minimum of 36mm can be highly beneficial. This wider unit allows for larger gaps between the panes, which can improve insulation performance by up to 50% compared to double glazing or narrower triple glazing units.
5. Cost vs. Benefit: While triple glazing can offer better performance, it also comes at a higher cost. If the triple glazing unit is only slightly better than double glazing due to standard thickness constraints, it may not be worth the extra investment. However, if you opt for wider units with the appropriate specifications, the enhanced insulation and energy savings can justify the additional expense, especially in colder climates or for properties requiring superior thermal performance.
6. Other Considerations: When deciding between double and triple glazing, consider the following:
- Climate: In colder regions, the enhanced insulation of triple glazing can lead to significant energy savings and increased comfort.
- Noise Reduction: Triple glazing can provide better sound insulation, which is beneficial in noisy environments.
- Window Frame: Ensure your window frames can accommodate the thicker triple glazing units and provide the necessary structural support.
See more information in our double v triple glazing section.
Q. The decorative lead designs on my glass have gone all discoloured and mottled. What has happened?
A: The discoloration and mottling you are noticing on the decorative lead designs of your glass are a natural part of the aging process of lead. Here’s a detailed explanation:
1. Natural Oxidation Process: Lead is a soft, malleable metal that reacts with the environment. When exposed to air and moisture, lead undergoes a chemical reaction known as oxidation. This process causes the lead to develop a layer of lead oxide on its surface, which appears as discoloration or mottling.
2. Formation of Patina: Over time, the oxidation process continues, and the lead develops a dull grey patina. This patina is essentially a protective layer that forms on the surface of the lead, preventing further rapid deterioration. The appearance of this patina is a natural and expected outcome when lead is exposed to the atmosphere.
3. Time Frame of Oxidation: The rate at which lead oxidizes and develops a patina can vary widely depending on environmental conditions such as humidity, temperature, and air quality. In some cases, this process can occur relatively quickly, while in other situations, it may take several years for significant discoloration to become noticeable.
4. Impact on Aesthetics: While the patina that forms on lead can alter its appearance, giving it a mottled or discoloured look, it does not compromise the structural integrity or functionality of the lead designs. Many people appreciate the patina for the antique or weathered look it provides, adding character to the decorative elements of the glass.
5. Maintenance and Restoration: If you prefer to maintain the original bright appearance of the lead, regular cleaning with a gentle, non-abrasive cleaner can help slow down the oxidation process. However, it is challenging to completely prevent oxidation over the long term. For those looking to restore the lead to its original look, there are specialist products and services available that can clean and reseal the lead, though these treatments may need to be repeated periodically.
Please see our lead section for further information.
