Protection

Why does damaged glazing cost so much more than the glass?

Once windows, screens and curtain walling are in, they stop being a package and become an obstacle. Every trade that follows works around them: plasterers, renderers, painters, fire-stopping crews, grinders and welders, and the general traffic of ladders, boards and scaffold. Glass is unforgiving of all of it. Paint overspray can sometimes be cleaned. Plaster and mortar splashes etch. Weld and grinding spatter embeds. A scratch does not polish out of a coated pane, and a sealed unit cannot be repaired in place.

So the number on the invoice is only the start. A replacement means a new unit ordered to a lead time, access re-established, glaziers back on site, a crane or a hoist if the pane is large, and a hole in the elevation until it arrives. On a housing scheme our own guidance puts a single large pane at roughly £500 to £1,000 before labour and programme are counted; on a commercial facade the numbers climb well past that. Multiply by the handful of panes that get caught on almost every job and the exposure is real money — and it lands late, at snagging, when the programme has no slack left in it.

The maddening part is that this is not a quality problem. It is not caused by bad workmanship on the glazing; it is caused by everyone else doing their job in the same space. That is why protection is a sequencing decision, not a trade preference: the film needs to be on the glass from the moment the units are installed, not from the moment somebody notices the first scratch.

Spray or film — what actually goes wrong with taped protection?

Cut-to-size polythene and masking tape is the default, and it fails in predictable ways. It is slow: someone measures, cuts, offers up and tapes every pane, and shaped or oversized glass takes longer still. It leaves gaps: tape follows a straight edge, so gaskets, beads, transoms and the last few millimetres at the perimeter stay exposed — which is exactly where render and plaster run down and collect. It lifts: wind, rain and UV work at the edges until a corner is free, and once air is under a sheet it flogs itself loose. And it traps grit: a sheet that has come half away holds dust and sand against the glass and is then rubbed across it by the wind, which scratches the pane the sheet was there to protect.

A sprayed liquid removes the seam from the equation. Intelligent Protect is applied wet and dries to a continuous peelable film that follows the surface it is on — across the pane, into the rebate, over the frame profile, round a curve or a shaped head. There is no edge for water to get behind because the edge is bonded, and there is no join for debris to creep under because there is no join. On large or awkward glazing the speed difference is the headline: at Harrow, floors of over 150 m² of glazing were protected in a single day each.

Which product protects which surface?

Three products cover the surfaces that get damaged on a typical build. They are not interchangeable — one is sprayed onto glazing, two are brushed onto hard horizontal finishes — so specify by what is being protected rather than by what is on the shelf.

View the protection range Coverage rates

How long can the film stay on, and how does it come off?

Exposure window is the question that decides whether a temporary coating is fit for a construction programme, because programmes slip. Intelligent Protect is rated for up to 18 months externally and up to 24 months internally. It is weather and UV resistant straight from the tub, with no separate top coat required — which matters, because many peelable coatings on the market manage around twelve months and need overcoating to survive outdoors. That difference is the difference between a film that is still doing its job at practical completion and one that has gone chalky and started letting go halfway through the fit-out.

Removal is a peel, not a solvent job and not a scrape. The film releases as a sheet and takes the render, paint and dust it collected with it, leaving the glass as it went in. Because there is no adhesive there is no residue to clean off, so the glazing does not need a second clean before handover. The dried film is recyclable. On a big elevation the practical method is to start a corner, get a hand behind it and pull steadily across the pane; on framed openings, run the peel from the frame inwards so the perimeter comes away in one piece.

Two practical constraints belong in the method statement. First, the surface must be clean and dry before application — a sprayed film bonds to whatever is on the glass, and it cannot take dust off afterwards. Second, we recommend a seven-day patch test on the actual substrate before a full application, particularly on anything unusual: coated or heritage glass, specialist powder-coat finishes, painted surfaces and factory films. Intelligent Protect is not suitable for wooden windows or doors.

Has it been proved on a real project?

At a large student accommodation development in Harrow, Intelligent Protect was used to protect over 1,500 m² of glazing. It was applied floor by floor, immediately after the window units were installed, with each floor of more than 150 m² of glazing protected in a single day — fast enough that the protection did not become the thing holding up the following trades.

The glazing then sat behind the film through plastering, painting and fire treatment works. At the end of the build the film was peeled away, and the project reached handover without a single glazing replacement — no re-order lead times, no return visits by the glazier, and none of the embodied carbon of re-manufacturing units that were already fit for purpose.

Read the Harrow case study

See it on site

Look at a coated and a peeled elevation before you commit to a method. The 360° tours let you walk projects where our coatings are in place; the video channel shows spray application and peel-off in real time.

360° site tours Application videos

Further reading

The guides below cover the category in more depth — spray versus taped film, sill and worktop protection, the recycled content of the coating, and the supply-and-apply service.

• Spray-on window and glass protection: the full guide
• Protecting glazing on site with peelable spray film
• The complete window protection kit for site
• Protecting baths, trays and worktops during the build
• Protecting worktops, sills and trays from site damage
• Intelligent Protect: made from 70% recycled materials
• Spray-on window protection: save time and money on site
• IPAC — our approved nationwide installers

Protecting steel rather than glass? See anti-corrosion and flame-retardant protection for steel. Working on a facade or a re-clad at the same time, see commercial and high-rise, light gauge steel and retrofit and social housing.

Frequently asked questions