Glass thickness

I was at an old chapel recently which was converted to flats perhaps ten years ago. An accident had revealed something that anyone living in such a building might want to be aware of.

A window, some six feet off the ground, had been broken, and the owner had kept a piece of the blue glass which she would like me to replace.

I noticed it was very thin; in fact, it was one-sixteenth of an inch (about 1.5mm) thick. (The Methodists who built the chapel clearly didn't believe in spending any more on luxuries like glass than they really had to.) Being over 1500mm above the ground the building reg rules about thickness won't actually apply, but tapping some of the (unbroken) windows around the property we came to the view that there could be some glass of that thickness at a lower height elsewhere in the building.

The coloured glass I normally use is 3mm (one-eighth) thick; in some high rick places 4mm is preferred (or required, in Building Regs).

The thinner glass breaks very easily.

I have a suspicion that glass thickness had not been on the list of things that were thoroughly checked by Building Control when the conversion was done - it is difficult to tell glass thickness when it's in a window! The piece will have to be replaced with 3mm glass, it's almost impossible to get hold of anything thinner these days.