Aluminum Curtain Wall Restoration

AquaSurTech

Improving quality & affordability, High-rises and Multiples, Aluminum Curtain Wall Restoration

Montréal, Quebec
Case Study Number 34

http://www.cmhc.ca/en/imquaf/himu/bebufa_034.cfm

http://www.cmhc.ca/fr/amquablo/toenha/fiinmico_035.cfm

Aluminum Curtain Wall Restoration

Overview

This prestigious high-rise complex designed by Ludwig Mies van der Rohe in 1967 is located in an affluent area of Montréal. It combines two residential towers, one office tower, as well as an underground concourse of shops, restaurants and medical facilities. Van der Rohe’s visionary design, well known by the building envelope’s striking black aluminum curtain wall was long overdue for a complete restoration. The property management team was intent on revitalizing the complex with a long-term, economical solution that would maintain both the status and investment value for the new owners.

Assessment

The exterior curtain wall system, made up of anodized aluminum panels, window mullions and guide rails, had suffered extreme deterioration to the original black anodization. UV discoloration, pollution and weathering in general, resulted in fading and “chalking”, thus leaving the finish dull and in some areas completely removed. The western and southern exposures suffered the most severe damage, particularly at the top, though time had taken its toll on the entire surface area. The new owners were intent on finding an efficient, long-term, ecological and cost-effective solution.

Building after re-coating

Solution

Faced with the prospect of either refurbishing offsite, or replacing the existing curtain-wall (at a cost too exorbitant to consider), the new owners chose a polyurethane acrylic waterborne coating that would renew the appearance and protect the curtain wall elements. In essence, the system is like an on-site re-anodizing process.

The process has several advantages:

Low odor and low Volatile Organic Compounds (VOCs);
Waterless surface preparation;
No primer required on Aluminum Substrate;
Low film buildup of approx. 1 mil (DFT);
Minimal over spray with High Volume Low Pressure (HVLP) equipment.

The Work

After an extensive review by the City’s Architectural Committee, including the submission of technical documents, as well as on-site visits to verify sample applications on the building done in 2000 and 2001, final approval was granted. Intent on preserving the integrity of the property and Mies van der Rohe’s design concept, van der Rohe’s office in Chicago also participated in the demanding review process.

The applicators worked as a two-man team, the minimum required personnel to operate the permanent swing stage system.

Work progressed in the following manner:

Surface Preparation consisted of manually applying a cleaning solution, in order to remove all chalking and dirt;
Windows were taped and covered with paper;
Black Matte finish coat (15 per cent Gloss) was applied using the HVLP spray system;
All tape and paper were removed;
Paint (minimal) was removed from the windows;
The windows were washed during the regular maintenance schedule.

Building before re-coating During the coating process

The Cost

The cost of refurbishing Phase I of the project, namely the Western Façade of Tower 3, was $110,000. The surface area is approximately 2,800 m² (30,000 sq.ft.), so the cost was about $39/m² ($3.67 per square foot). There were approximately 600 window units (including panels, glass, guide rails and mullions) in this 20 storey tower. Consequently, the cost for this restoration is also equivalent to approximately $183 per window unit. The system carries a 10 year Warranty against UV Discoloration, peeling, or blistering.

Total project cost will approach $1 million, with completion set for 2005.

Results

All concerned in this project - tenants, management and owners, were extremely pleased with the like-new results, minimal disruption and cleanup, low odor and low VOCs.

Before During After

Property Manager:             Restoration company                               Coating Applicator
COJIR Inc.                                 AquaSurTech Coatings, N.A                               Belcouleurs Inc.
Gilbert Killeen                            Howard Dolman , acp@aquasurtech.com             Alberto Stabile, cstabile@totalnet

Before AquaSurTech’s water base, low VOC direct to aluminum, simple prep, long life, D45 Coating & After

Photos of the 22 year old anodized aluminum curtainwall

panel, damaged by the sun & pollution, that was restored

using the AquaSurTech Coating System:

AST Decontaminator Cleaner and AST D45 Clear Coat.

Maison Alcan Head Office, Montreal, Canada