A method for producing a vacuum insulated glazing unit, the method comprising: o providing a first glass pane having an inner surface with a peripheral edge; o positioning a side seal material on the peripheral edge of the inner surface of the first glass pane, wherein the side seal material comprises a solder glass material component; o pre-heating the side seal material to a pre-heating temperature (T PH) using a pre-heating heat source, wherein at the pre-heating temperature (T PH) the side seal material foams and densifies to form a dense side seal material, wherein during foaming of the side seal material gaseous inclusions from the side seal material outgasses, wherein the side seal material has: - an initial side seal density prior to being pre-heated; - a foaming side seal density during foaming of the side seal material, wherein the initial side seal density is larger than the foaming side seal density by at least 50%; and - a dense side seal density after pre-heating of the side seal material where the dense side seal material is formed, wherein the dense side seal density is larger than the foamed side seal density by at least 50%, wherein the method further comprises: o providing a second glass pane having an inner surface, o providing spacers, and o assembling the VIG unit such that the VIG unit comprises: • the first glass pane and the second glass pane arranged in parallel with the inner surfaces opposing each other; • spacers arranged between the opposed inner surfaces, and o the dense side seal material peripherally arranged between the first glass pane and the second glass pane creating a sealed cavity between the glass panes. o providing a first glass pane having an inner surface with a peripheral edge; o positioning a side seal material on the peripheral edge of the inner surface of the first glass pane, wherein the side seal material comprises a solder glass material component; o pre-heating the side seal material to a pre-heating temperature (T PH) using a pre-heating heat source, wherein at the pre-heating temperature (T PH) the side seal material foams and densifies to form a dense side seal material, wherein during foaming of the side seal material gaseous inclusions from the side seal material outgasses, wherein the side seal material has: - an initial side seal density prior to being pre-heated; - a foaming side seal density during foaming of the side seal material, wherein the initial side seal density is larger than the foaming side seal density by at least 50%; and - a dense side seal density after pre-heating of the side seal material where the dense side seal material is formed, wherein the dense side seal density is larger than the foamed side seal density by at least 50%, - an initial side seal density prior to being pre-heated; - a foaming side seal density during foaming of the side seal material, wherein the initial side seal density is larger than the foaming side seal density by at least 50%; and - a dense side seal density after pre-heating of the side seal material where the dense side seal material is formed, wherein the dense side seal density is larger than the foamed side seal density by at least 50%, o providing a second glass pane having an inner surface, o providing spacers, and o assembling the VIG unit such that the VIG unit comprises: • the first glass pane and the second glass pane arranged in parallel with the inner surfaces opposing each other; • spacers arranged between the opposed inner surfaces, and • the first glass pane and the second glass pane arranged in parallel with the inner surfaces opposing each other; • spacers arranged between the opposed inner surfaces, and o the dense side seal material peripherally arranged between the first glass pane and the second glass pane creating a sealed cavity between the glass panes.