Why do DGU's Mist Up?
DGU’s often mist up due to cracked or damaged sealant which allows air inside the seal and between the glass panes. This air condenses and then creates mist. Many older DGU’s have a 2 part sealant (brown/purple or grey) which is now at the end of life.
A swiggle strip is black and bumpy, this could also have been used. The swiggle strip incorporates the sealant and spacer, thereby removing the trapped air at DGU manufacture. However, swiggle strips are affected by UV and the majority are now breaking down. The main reason a modern DGU fails is due to the fitting. If both glass panes are not packed on level glazing packers then one side may slip and break the seal. The damage may not show for a few years but if fitted correctly, a quality DGU should not break down and mist up.
DGU are guaranteed for 10 years from misting up. Your DGU’s are the best quality available and are sealed with BOSTIK 5000™ hot melt (190°C) butyl sealant.
They fully comply with both the European standard EN1279 parts 2,3,4 and 6 and the US/Canadian standard ASTM E2190.
Breakages or cracks in glass are guaranteed for 14 days from installation and scratches or marks must be reported within 48 hours of the installation to be replaced for free. Handles, hinges and locks are guaranteed for 12 months and any defects (marks or scratches) must be reported within 48 hours of fitting to get replaced for free.