Restoring historic windows is a delicate balance of technique, tradition, and performance. One particular challenge is preserving the original appearance of windows that use beaded glazing, especially in heritage buildings. That’s where Hodgson Sealants’ H7 Glazing System shines. Purpose-built for beaded applications, the H7 system delivers outstanding performance while maintaining the authentic appearance required for conservation-grade work.
Whether you’re a professional glazier, restoration contractor, or an enthusiastic DIYer working on a period home, the H7 system brings together the flexibility of modern glazing putty with the classic aesthetic of traditional craftsmanship.
Built for Conservation and Compliance
The H7 Glazing System is tailored for the restoration of listed buildings, heritage sites, and conservation area properties. It is particularly effective for reduced sightline IGUs (Insulating Glass Units) and single glazing in bead-glazed window frames made from timber, steel, concrete, or stone.
Importantly, the H7 system complies with BS6262 (Glazing for Buildings) and GGF guidelines, ensuring that it meets national standards for installation, longevity, and performance. It’s rated for up to 2300 Pa of wind and water exposure, making it suitable even for exposed and weather-prone areas.
Single-Product Simplicity: Just Heritage Putty
One of the standout features of the H7 system is its single-compound solution. Unlike other systems like H5 and H1, which use both a bedding putty and a separate fronting putty, H7 uses Heritage Putty alone. This not only simplifies the process but also ensures a uniform aesthetic throughout the installation.
Heritage Putty is a linseed oil-based formulation that offers enhanced elasticity, allowing it to move with timber or metal frames as they expand and contract with environmental changes. This movement accommodation is crucial in heritage glazing applications, where materials are often more dynamic than in modern PVC frames.
Ideal for Beaded Glazing
Traditional windows often feature external beading to hold the glass in place. Modern sealants struggle with the tight rebates and narrow sightlines of these windows. The H7 system, however, is designed specifically for this purpose.
The installation method includes:
- Removing beads and preparing the rebate.
- Bedding the IGU or glass pane in Heritage Putty.
- Reapplying the bead using non-rusting pins and embedding it into a second layer of putty.
- Tooling the front edge to form a weatherproof fillet.
This technique results in an extremely weather-tight seal while preserving the slender, clean lines of period windows. It’s also ideal for multi-pane or bar-style windows that require precision detailing.
Easy to Paint, Easy to Maintain
A frequent concern with traditional putties is how long they take to dry. Fortunately, Heritage Putty has been engineered for quick skin formation, enabling paint to be applied within days of installation depending on ambient temperature and humidity.
It works with both solvent- and water-based paints, though water-based systems may speed up drying time. For best results, painting should take place shortly after installation to protect the putty from UV and moisture. Always test compatibility when using new or specialty coatings.
Long-term maintenance is refreshingly easy. If any part of the glazing begins to degrade, you can remove and replace just that section of putty, no need to disassemble the entire unit. This makes the H7 system both cost-effective and sustainable in the long run.
Environmentally Conscious and Authentic
Made from natural linseed oil and chalk, Heritage Putty has a far smaller environmental footprint than synthetic sealants. It emits up to 40% less carbon during manufacturing, produces less waste, and allows homeowners to retain existing timber frames, avoiding unnecessary replacement costs.
Restoring rather than replacing is also more authentic. The H7 system delivers not just performance, but the classic charm that defines historic buildings, without compromise.
Why the H7 System is Essential for Heritage Window Restoration
The Hodgson H7 Glazing System proves that simplicity and authenticity can go hand-in-hand with modern performance. With its focus on beaded glazing, compatibility with narrow rebates, and heritage accuracy, it’s a must-have solution for anyone working on traditional or listed windows.
If your goal is to restore rather than replace, and you need something that performs as well as it looks, the H7 system offers an ideal blend of tradition, compliance, and craftsmanship.