Does door glass have to be safety glass?

In the critical zone, yes. Glazing in a door and in a door side panel from floor level up to 1500mm has to break safely, which means Class 3 to BS EN 12600 or Class C to BS 6206. Where a pane in a door or side panel is wider than 900mm, Class 2 or Class B is accepted.

Can I keep using the door until the glazier comes?

Better not to. Every closure loads a pane that has already lost its strength, at the height where a break causes the worst injuries. Wedge it open or out of use and tape the crack on both faces.

My old front door has thin single glazing. Should it be replaced?

If it breaks, the replacement has to meet the current safety glazing requirement for that position — and worth knowing that laminated glass is often chosen for doors because it holds together on its interlayer rather than clearing the opening. Replacing sound old glass is a judgement call; replacing broken glass is not.

Why did the pane crack when nobody hit it?

Usually the door. A dropped or binding door bends the pane a little on every closure, and a sunlit door with a dark frame adds thermal stress. That is why the glazier looks at how the door hangs, not just at the glass.

High risk

Updated 30 August 2026

Cracked Glass In A Door

The pane in a front, back or internal door has cracked, and the door still gets used every day.

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What's happening?

Glass in a door is treated differently from glass in a window, and the reason is where people meet it. Doors are pushed, and they stick, and hands and arms arrive at the glass at exactly the height that causes the worst injuries. The impact guidance therefore treats glazing in a door, and in the side panels beside a door, as a critical location over a much taller zone than for a window: up to 1500mm from floor level in doors and side panels, against 800mm for ordinary window glazing. Glass in those positions has to break safely. A cracked pane in a door has already lost its strength, in the one location where the rules are strictest, and it is used dozens of times a day.

What usually causes it?

The door slamming or being pushed hard on a pane with existing edge damage
A sticking door being shoved at the glass rather than at the frame or handle
A dropped or binding door putting the pane into bending every time it closes
Impact from a pet, a pushchair, a hoover or furniture being carried through
Old annealed glass in a period door that never met current safety glazing expectations
Thermal stress on a sunlit glazed door with a dark frame
Failed putty or beads letting the pane move in the rebate until it cracks at a corner

Is it dangerous?

Yes, and more so than the same crack in a window. This is the position the safety glazing rules exist for: an impact between waist and shoulder height can be followed by a fall through the glazing, adding injury to the face and body, and hands, wrists and arms are especially exposed. Where the pane is old annealed glass it will break into long shards. Stop using the door if you reasonably can, or stop it being pushed on the glass, and get it dealt with the same day.

Can I fix it myself?

Taping both faces to hold the pieces and stopping the door being used are the sensible immediate steps. Prop or wedge the door rather than letting it swing, so it cannot be caught by wind. Do not de-glaze it yourself, and do not fit a plain pane of glass cut to size from a merchant as a replacement: in this location the glass has to break safely, and ordinary annealed glass does not.

When should you call a glazier?

Call a glazier the same day. Say it is a door pane when you call, because it changes the priority and the glass that gets ordered. Mention if the door binds or has dropped, since a door that is being forced will crack the replacement too, and the fix has to include the door rather than only the glass.

What will the glazier actually do?

Make the pane safe and take the door out of use or secure it in position
De-glaze and clear the rebate, checking for the edge damage that started the crack
Confirm the critical location and specify glass that breaks safely — Class 3 to BS EN 12600 or Class C to BS 6206, or Class 2 or Class B where the pane in a door or side panel is wider than 900mm
Glaze the new pane on setting blocks with the correct beads, gaskets or putty for the door
Ease and re-hang a binding or dropped door so the pane is no longer being loaded when it closes
Check the side panels next to the door, which sit in the same critical zone

Where safety glass is required

The impact guidance defines critical locations by height from floor level, and the zone is taller around doors than elsewhere because of how people collide with them.

In doors and door side panels: glazing from floor level up to 1500mm, including a 300mm-wide zone in the panel beside the door.
In windows, walls and partitions away from doors: glazing from floor level up to 800mm.
Glass in those locations must satisfy Class 3 of BS EN 12600 or Class C of BS 6206.
Where a pane in a door or door side panel is wider than 900mm, Class 2 of BS EN 12600 or Class B of BS 6206 is accepted.
Small panes in glazing bars or traditional leaded lights, and permanently protected glazing, are alternative routes to compliance.

Frequently asked questions

We’re happy to answer all your questions.

Sources & References

Cracked Window GlassCaution Smashed Window PaneHigh risk Toughened Glass Shattered On Its OwnHigh risk

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