Glass and mirrors in designer interiors: why calculations are impossible, and where defects happen

“With glass, it's hard to predict”

Our guest is Artem, an engineer at Elit Steklo. He's been with the company for five years: what drew him in was the approach itself — bringing complex projects to life, where the work is never monotonous and something new comes up every time. Today he designs glass and mirror pieces — and on almost every one of the studio's projects, he's the one responsible for making sure the conceived solution actually fits in place.

Glass is a fragile material. What sort of person does it take to design structures like these? It is engineering work, after all: it needs calculations.

With glass, calculations are a tricky business. It's generally hard to predict how glass will behave in any given situation. It's one thing to weld a metal structure: wind or no wind, it holds. With glass, I don't think you can really carry out precise load calculations.

So depending on the project, you need to understand: the solution has to be practical, has to work, and has to be safe for everyday use. That's discussed in advance, not tested on site.

A mirror is always raw glass

A mirror is fundamentally different from glass: it's always raw glass, and it needs additional protection. If a mirror is backlit or framed, an anti-shatter film is applied to the back. And the edge — the part of the glass that's the least protected, even when the glass is tempered — is covered with a profile.

These points are always discussed with the client in advance: sometimes it's more honest to explain that a particular solution is better left undone than to make it and end up with a problem in use.

What was done on this project

What did you do on our project — which elements, mirrors, glass?

Large-format bronze-tinted mirrors, glue-fixed. And a sliding shower screen.

Large format here means just over three metres. Compared with an ordinary mirror, that's a very small slice of the market: a mirror like that is hard to even find, it's supplied less often. It has to be brought in and cut — and that's where the risks really start.

Where defects happen

Every production process has a defect rate. What is it for mirrors and glass?

The defect rate depends on the complexity — on what we're trying to achieve. Take a mirror, especially large-format like this one, with all kinds of cutouts on top — it can break even at the factory. After that it has to be lifted, transported, carried up the stairs. That's a whole separate process.

Carrying it in: a team, not two installers

How do you get a mirror like that up to a high floor in a residential building?

A whole team goes out for that — two installers won't manage. How many people depends on the mirror's format and on how it can be carried in. Sometimes mirrors are lifted between flights of stairs, through narrow openings. Four people, sometimes six: the bigger the mirror or the glass, the heavier it is, and the more people you need.

On this project, any format could only be carried in by hand up the stairs — and that's always a risk. The human factor: you pick up the mirror the wrong way, apply a bit too much force — and it cracks. As far as I know, everything here was carried in on the first attempt.

Millimetres: why there are sometimes two or three site measurements

The one difficulty on this project was a mirror that came out the wrong size. To avoid that, measurements are sometimes taken two or three times — and even then, something occasionally doesn't line up: you come out for the rough measurement, measure to the mark, and then something changes on site, so the mirror no longer matches the finished opening.

How is that fixed?

With mirrors, the only option is rework. If one is too tall or too wide, it can be trimmed: a few more passes on the machine, some extra polishing, and it comes down in size. As a rule, the inaccuracies are a few millimetres: two, three, five — not a hundred. If it can't be fixed at the factory, a new mirror is made.

Black spots on a mirror: how the complaint was handled

Black spots appeared on a mirror in the bedroom. Why did that happen, and how did it end?

Personally, I think it's a factory defect — substandard raw material, the amalgam composition. I can't say for certain, but it couldn't have come from the silicone sealant we use: it's the same one, used year after year, and it's already been through every test you could put it through. It's possible the manufacturer changed the formula — the ratio of components shifted. Whether that's a mistake or a cost-cutting move, I can't say.

How does the company handle complaints like that?

We replace it. We order the mirror from a different batch — with the same adhesive. That's what was done here, and the problem never came back.

The studio has worked with Elit Steklo for more than ten years. For a designer, this is a question not only of quality but of possibility: when you come up with a complex solution, some suppliers turn it down, others quote a price high enough to avoid taking it on. Here, even the most complex solutions get built: it's essentially an engineering company that works in glass.

When to call in the engineer

What advice would you give designers and clients?

From an engineer's point of view, the main one is to get in touch while the idea is still taking shape. Don't wait until the finishing is already done.

Then the solution can be designed together, and you can work out in advance whether it will be practical and whether it can actually be made. There's a lot to take into account: all sorts of finishes and joints. Joints are a frequent source of problems: the designer wants to do something at a joint, and from an engineering point of view it's simply not possible — a screw has to be fixed there, the tile could chip. All of this is worked through at the idea stage: the engineer provides a technical brief on the structure, the designer explains how they see it. Then a solution that works for everyone is found almost every time.