Repairing Double Glazed Windows Double-glazed Windows "blow", the gas that insulates them, argon, escapes, causing them reduce their energy efficiency. The good news is, blown double glazing is often repairable without having to replace the windows. The most common sign of a damaged window seal is condensation or water between https://www.repairmywindowsanddoors.co.uk/stevenage-windowrepair/