Top 5 Common Mistakes When Ordering Custom Cut Glass Online

Buyer’s Guide · 2025

Read time: ~6 mins · Updated: 21 Sep 2025

Ordering custom cut glass online can save time and money—but mistakes in the process can lead to wasted orders and costly replacements.
Here are the top 5 mistakes homeowners make when ordering glass online, and how you can avoid them.

Mistake 1: Wrong measurements

Many customers measure their old glass instead of the actual frame opening. This can result in panels that are too large or too small.
Always measure the frame opening in multiple places (top, middle, bottom for width; left, centre, right for height) and use the smallest measurement with a fitting tolerance (2–3 mm).

Pro tip: See guidance from FENSA on correct measuring for compliance.

Mistake 2: Choosing the wrong thickness

Glass that is too thin may flex or break, while unnecessarily thick glass adds cost and requires stronger hardware.
For most shower doors, 8 mm toughened is ideal; for balustrades, 10–12 mm may be required. Always match thickness to application.

Mistake 3: Ignoring safety glass rules

UK Building Regulations require safety glass (toughened or laminated) in “critical locations” like doors, side panels, or low-level glazing under 800 mm.
Ordering standard float glass for these locations is dangerous and non-compliant.

For reference, check Glass & Glazing Federation (GGF) safety guidance.

Mistake 4: Skipping edge finishing

Unfinished edges can be sharp and unsafe. Specifying polished edges or bevels not only improves safety but also appearance, especially for visible edges on shelves, table tops, or doors.

Mistake 5: Choosing only the cheapest option

Going with the lowest price can mean cutting corners on quality, certification, or after-sales service.
Look for suppliers who provide BS EN 12150 certified toughened glass or laminated glass, and clear warranty terms, even if it costs a little more.

Frequently asked questions

Can I measure old broken glass instead of the frame?
No—always measure the frame opening. Old glass may not represent the correct size and can result in errors.

Do I always need toughened glass?
Yes in critical locations like doors, low-level glazing, or bathrooms. Toughened glass is 5× stronger and safer than float glass.

What’s the best edge finish for shelves or table tops?
Polished edges are best for visibility and safety. Bevelled edges add decorative style but increase cost slightly.

Is laminated glass better than toughened?
Each has advantages. Laminated holds together on impact (best for security/balustrades), while toughened is stronger against sudden force. Sometimes they are combined.

Should I always pick the cheapest supplier?
Not always—low prices can mean poor aftercare or non-certified glass. Always check reviews, compliance stamps, and guarantees.