What is 4SG?
Ködispace 4SG is a warm-edge spacer system made by H.B. Fuller. It is a reactive thermoplastic with the desiccant built in, and it replaces the traditional edge of an insulating glass unit, a separate spacer, desiccant and primary seal, with a single applied material. ArcView uses it in the insulating glass units of our windows and doors.
Why the edge of the glass matters in Canada
In the Prairies or the GTA, a window sees freezing nights and hot afternoons in the same season. The glass and the gas between the panes expand and contract with every swing, and the edge seal takes that stress. When the seal fails, the argon escapes, moisture gets in, and the unit fogs between the panes.
A rigid metal spacer is also a thermal bridge: it conducts cold to the inside edge of the glass, which is where winter condensation usually starts.
What 4SG changes
One material instead of three. The spacer, desiccant and primary seal are applied as one continuous bead by an automated process, with no corner joints.
It bonds to the glass. H.B. Fuller's formulation chemically bonds to the glass and to the silicone secondary sealant, and stays flexible, so the edge moves with the glass rather than against it. H.B. Fuller reports no spacer migration and higher temperature stability than standard insulating glass sealed with PIB.
A warm edge. There is no metal in the spacer, so the inside edge of the glass stays warmer than with an aluminium or steel spacer, which reduces the conditions for edge condensation.
What the published tests show
According to H.B. Fuller, Ködispace 4SG is certified to ASTM E2188, E2189 and E2190, is on the IGCC/IGMA Reviewed Spacer list, and meets the European EN 1279-2 and EN 1279-3 requirements. In that EN 1279 testing, after five climate cycles the dew point stayed below −40 °C, the moisture penetration index (Iav) was at most 12%, and the gas content remained above 85%.
Those are accelerated laboratory cycles, not years of service; they are the standard way insulating glass durability is compared.
How this fits ArcView's warranty
H.B. Fuller supplies 4SG as a raw material; the warranty on the finished window comes from us, the fabricator that builds the insulating glass unit, not from the material supplier. Our insulated glass units carry a 20-year limited warranty against seal failure that causes moisture or dust between the panes, alongside 20 years on the aluminium frame and the powder-coated finish, 10 years on hardware, and one year on installation workmanship by our own crews. The full terms, including what is excluded, are on our warranty page.
Learn more
H.B. Fuller publishes the technical details on its Ködispace 4SG page. To see how 4SG glazing fits your project, book a free consultation.