Curtain wall · Montreal
Replacing curtain wall and commercial window glass
In an office tower or a condo building, one fogged or cracked unit in the glass façade is a common sight, and it rarely means the façade has to be redone. A curtain wall (mur-rideau) is built from framed units that can usually be replaced one at a time. We connect building owners, property managers and syndicates with independent commercial glass contractors who handle replacement at height, from a single unit to a batch. For street-level glass and doors, see all commercial glass.
- Single units, not whole façades
- Access at height planned ahead
- Office towers, condos and mixed buildings
How it works
Replacing a curtain wall unit without redoing the façade
A curtain wall is a glass wall hung on the building's structure rather than holding it up. The glass sits in an aluminum grid, one unit per bay, held by pressure plates and caps on the outside or by stops on the inside, depending on the system.
Because each unit sits in its own bay, a pro can usually remove the caps or stops around one unit, take out the failed glass and set a new unit of the same size, make-up and coating. The rest of the wall stays in place. Tint and coating show on a façade, so the pro will want to identify what's there before ordering.
Some systems are glazed from inside, which makes the job far simpler; others only from outside. That one detail changes the whole plan.
Fogged units
Fogged thermos units in office and condo towers
The glass in most curtain walls and tower windows is a sealed insulating unit, what Quebeckers call a thermos. When its edge seal fails, moisture gets in and the unit fogs between the panes. When it's more than one, work through it in order:
Map the affected units
Note the floor, the façade and the position of each fogged or cracked unit. Photos from inside, with the position marked, save the pro a trip.
Look for the paperwork
Building records may name the original installer and any warranty. The pro can also read the markings on the unit's spacer.
One at a time, or a batch
Replacing units together spreads the cost of access over more glass. If others show early signs, it can make sense to include them. See foggy thermos units for how fog is diagnosed.
Access
Access at height and planning
On a tower, reaching the glass is often the biggest part of the job. The pro will look at three things:
Inside or outside
Inside-glazed units can often be changed from the suite or office, with furniture moved and floors protected. Outside-glazed units need exterior access.
Lift or suspended platform
Lower floors may be reachable with a lift from the ground; higher ones usually call for a suspended platform or rope access. The building's roof anchors and roof access decide what's possible.
Building management
Occupants, elevators, loading areas and the sidewalk below all need coordinating. In a condo, bring in the syndicate or its manager early; see condo syndicates and owners.
Office windows
Office and commercial building windows
Not every commercial building has a curtain wall. Many offices and mixed-use buildings have ordinary windows set in masonry or aluminum frames, some of them original. The choice is the same as at home: replace the thermos when the frame is sound, and the window when it isn't.
In Quebec, door, window and glazed curtain wall work falls under the RBQ's licence rules for contractors, in the specialized subclass for doors and windows, and licensed contractors must show their licence number on their promotional material. Ask for it with the quote.
Permits are the borough's call. Most boroughs require one even for same-size window replacement, and commercial and mixed buildings carry a higher minimum analysis fee than homes. The ground floor of the same buildings is covered on our storefront glass page.
What affects the quote
What drives the price of commercial glass replacement
Glass at height is priced on access as much as on glass. Expect the quote to depend on:
- The number of units, and whether they can be done in one visit
- Unit size, glass make-up, tint and coatings that match the façade
- Inside or outside glazing, and the system's caps and stops
- Access: lift, suspended platform or rope access, and roof anchors
- The floor, the occupants and the hours when work can happen
- Temporary protection if a cracked unit has to wait for its replacement
Send the address, the floor, the number of units affected and photos from inside and, if possible, from the street.
Winter
Glass at height: what the 1998 ice storm taught downtown
Many Montrealers remember January 1998, when parts of downtown and Old Montreal were closed off because large sheets of ice were falling from buildings.
Height and winter change the job. Freezing rain comes every winter, and ice builds on ledges and frames. A cracked unit high on a façade is a safety question before it's a glass question: if pieces could fall, keep the area below clear and alert the building manager. Work at height depends on the weather, so a winter replacement may wait for a safe day, with a temporary measure in the meantime.
At home
Curtain walls in homes
The term mur-rideau also turns up in house projects: a two-storey wall of glass over a living room, or a glazed stairwell on a contemporary infill. These are usually built with commercial framing and large thermos units, so the same pros and the same logic apply, and a failed unit can generally be replaced on its own.
Ordinary house windows are simpler. If you're weighing new glass against new windows, our repair-or-replace guide walks through the choice.
Questions
Curtain wall questions
Explore your options
Related commercial glass
Local pros replace commercial and tower glass downtown and in the surrounding cities, including Montréal, Saint-Laurent, Laval, Longueuil and Brossard.
Tell us the address, the floor and the units
Say how many units are affected, on which floors and façades, and whether any are cracked. We pass it to an independent commercial glass contractor who plans the access and quotes the work.