colorado state capitol dome restoration
COLORADO STATE CAPITOL DOME RESTORATION 2015 Palladio Awards Submission – Civic Restoration Preservation
SUMMARY PROJECT DESCRIPTION COLORADO STATE CAPITOL DOME RESTORATION 2015 Palladio Awards Submission – Civic Restoration Preservation In September 2014, after four years of planning and construction, the $15 million restoration of the Colorado State Capitol Dome was concluded with a public rededication. Today considered one of the most important historic buildings in the State of Colorado, the Colorado State Capitol was completed in 1903 after a seventeen year period of construction, and is the defining structure of downtown Denver’s historic public building complex and the public park surrounding it. The project encompassed the comprehensive restoration of the cast iron and sheet metal cladding of the masonry and steel frame circular drum and dome, which rises 172 feet above the main roof of the Capitol building. The dome, having survived for over 100 years, was structurally sound but 100 years of wear left the cast iron and sheet metal skin and 106 windows deteriorated and in need of restoration. The primary goal for the project was to restore the historic dome to its original grandeur and to prepare it for another one hundred years of low maintenance use as the symbol of democracy and public pride for the State of Colorado. The cast iron cladding and gilded copper dome with 106 windows, which brings daylight into the center of the Capitol, had been repaired and painted periodically over the dome’s life, but recent failures of cast iron cladding above the observation platform and patterns of rust staining revealed more serious deterioration which was hidden beneath many layers of paint and caulk. Early investigations also revealed shortcomings in the original design and construction which compromised the dome’s ability to shed rain and stand up to the elements. The dome restoration included the removal and repainting of 100 years of paint as well as selected dismantling and reconstruction of all cast iron surfaces and decorative elements. The glided sheet metal dome roofing was replaced and all decorative sheet metal elements were restored. The project also restored the 106 original wood windows, which allow natural light to flood the historic Capitol interior.
UNUSUAL FEATURES & DESIGN CHALLENGES This restoration represented a special opportunity to employ traditional construction techniques to preserve and restore the original construction while also utilizing state of the art contemporary building technologies to provide a comprehensive restoration and improve on shortcomings of the original design and technologies available 110 years ago. Unusual to the design process, the design team recommended that a significant forensic survey and building evaluation, including selective dismantling and testing of alternative treatments, be undertaken to ensure a thorough understanding of the treatments required and the use of the highest quality restoration techniques. The design team partnered with the Construction Manager and the State Architect to complete this process, which led to a higher quality and more cost-effective project for the State of Colorado. We found a long history of water penetration had led to areas of structural deterioration in the supportive iron framing, as well as the failure of cast iron and the steel fasteners which held the cladding in place. The wood windows were in need of serious repair, and the decorative sheet metal copper dome was compromised by the effects of 100 years of expansion and contraction and patterns of severe weather including hail storms and ice damage. To ensure a quality result, 100 years of paint build up needed to be removed to reveal failures in the cast iron cladding assembly and fasteners and to create a high quality base surface for repainting. Selected areas of cast iron cladding, like built-in guttering, decorative cornices, and ornamental balustrades, had to be dismantled and reconstructed. Broken and deteriorated cast iron elements were shipped to the foundry for repair and/ or recasting. Historic cast iron was manufactured like a kit of parts but the idiosyncratic fit of the original elements had required cutting and fabrication in the field during restoration, replicating the process of the original construction team. We estimate that 98% of the original cast iron was retained in the restoration. The restoration included an aggressive effort to replace the original rusted mild steel fasteners with new stainless steel fasteners. All 106 windows were removed, dismantled, and restored in a controlled shop environment. The sheet metal work on the dome was replaced while all original decorative elements were removed, restored, and reinstalled. The new sheet metal copper roof provides a superior base for the application of the gold leaf gilding which replicates the original dome finish. In selected areas, new structural decking was installed where it was originally omitted to resist future sheet metal failure. New technologies in under-roof waterproof membrane, improved expansion control detailing, and high performance sealant and caulks were carefully planned to ensure a waterproof envelope for the restored structure. The restoration team was challenged to provide good worker access to this project which extended above the main roof of the Capitol building 172 feet. Thirty five tons of specially designed scaffolding was constructed above the Capitol roof and enclosed with a plastic scrim for two years to provide access for the three year restoration process. This restoration represented a major milestone in a multi-decade restoration and renewal process for the Colorado State Capitol Building and it serves as an excellent model for other state capitol structures around the country.
GRANT STREET
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EAST COLFAX AVENUE
STAGING AREA
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TRAFFIC
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SITE PLAN
TR
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9 I
H 16' - 8 1/2" ± DECK
8
10
TYP. EJ EJ
EJ
4' - 8 3/4" 1/4" PER FT. (VIF)
EXIST. SLOPE DN
7
J
DECK TYP.
G
11
B.9
EJ
EJ
F
K
B.8
UP
DN ) PE O VIF .( SL FT T. IS ER EX " P /4 1
B.10
6 B.7 B.11
12 EX IST .S LO PE "P DN ER FT . (V IF)
1/4
EJ E
EJ L
B.12
B.6
13
5 DN
EXIST. SLOPE DN
B.13 EJ
EJ
1/4" PER FT. (VIF)
B.5 (ABOVE)
R
24
'-
11
3/4
"±
ROTUNDA OPEN TO BELOW
B.4
D
. C.I
4
14
B.15
3' 6
1/4
OBSERVATION DECK
R3
M EJ
"±
B.3
DN ) PE VIF O .( SL FT T. IS ER EX " P /4 1
B.14
DE CK
EJ
B.16
B.2
EX IS T "P .S ER LO PE FT D .( VIF N )
B.1
C
N
EJ
3
1/4" PER FT. (VIF)
EXIST. SLOPE DN
EJ
15
O
B
EJ
EJ
EJ
16
2 A
P
1
OBSERVATION DECK PLAN
KEY PRODUCTS, MATERIALS & SUPPLIERS Gold Leaf: AngloGold Ashanti w/ Cripple Creek & Victor Gold Mining Company High Performance Coating System: Sherwin Williams Exterior Deck Coating: Dex-o-Tex Copper Roofing Material: Firestone UNA-CLAD Copper Access and Scaffolding: Atlantic Scaffolding Sealants: DOW Corning Sealant
KEY CONTRACTORS, SUB-CONTRACTORS & CRAFTSPEOPLE The project was constructed by the following team: Construction Manager
G H Phipps Construction Inc. Greenwood Village, Colo.
Consulting Construction Manager
The Christman Co. Lansing Michigan
Cast Iron Specialist
Robinson Iron Alexander City, Alabama
Paint Restoration Subcontractor
A G S Construction, Inc Littleton , Colorado
Sheet Metal Roofing Subcontractor
Douglas Colony Group, Inc Commerce City, Colorado
Window Restoration Subcontractor
Lyons Historic Windows Denver, Colorado
Gold leaf Gilding Subcontractor
Evergreen Studios New York , New York
PHOTO 1 Before: An overview of the Colorado State Capitol Building and Dome (DRUM and Dome). 110 years without major renovation, failing cast iron, deteriorated sheet copper dome and deteriorated windows needed comprehensive restoration. The Dome rises 272 feet about grade is major architectural landmark for the State of Colorado.
PHOTO 2 Before: A partial elevation of the cast iron cladding and columns showing water and rust staining at the belt courses which demonstrate more extensive concealed deterioration. Note the safety netting at the upper cornice installed after cast iron failure in 2006.
INSET A
INSET B
PHOTO 3 Design Stage Forensics - Selective dismantling and testing during the design process revealed specific areas of structural deterioration and provided an opportunity for proper material science research to guide the high-quality long-term restoration. Aerial photo - Showing the scaffolding required for detail forensics and documentation during design. Inset A: Removed cast iron cornice face and built in gutter revealed failed structural wrought iron structure. Inset B: Selective dismantling of decorative sheet metal dome confirmed deterioration of sheet metal work, and guided design detailing for improved weather proofing and structural reinforcement in the restoration.
PHOTO 4 During Construction: Removal of 100 years of paint helped to confirm original cast iron assembly and requirements for repair and restoration. Alternate paint removal strategies were tested to determine most cost effective approach for achieving the required bare metal finish for the new high performance painting.
PHOTO 5 During Restoration: Restored cast iron entablature reconstructed and in place. Inset: Failed cast iron entablature above major columns removed for repair and restoration.
PHOTO 6 During Restoration: Upper dome fully scaffolded for construction revealed gilded sheet metal condition compromised by 100 years of harsh weather, hail, and temperature extremes.
PHOTO 7 During Restoration: Showing restoration of the sheet metal roofing. Field sheet metal is replaced with new cooper with improved expansion control. All original decorative elements were removed restored and reinstalled in the reconstruction of dome roofing.
PHOTO 8 After: Overall view of restored cast iron drum and dome with new gilded sheet metal dome structure and lantern.
PHOTO 9 After: Detail view of restored column capitols and the reconstructed cast iron entablature structure.
PHOTO 10 After: Overall night time view of the restored State Capitol Dome with cast iron drum and gold leaf glided dome, one of the most important landmarks in greater Denver and the State of Colorado.
WE SEE A BETTER WORLD The experienced professionals at Quinn Evans Architects are committed to elegance in design and well-crafted solutions that sustain and renew the tradition of our built environment. Quinn Evans Architects (QEA) is a full service architectural firm with offices in Washington, D.C., Ann Arbor and Detroit, Michigan and Madison, Wisconsin. In order to meet our clients’ needs, our comprehensive services include architecture, preservation, interior design, planning, and landscape architecture. Our creative and sensitive design solutions have addressed the renovation and restoration of existing structures and sites, preservation and reuse of important buildings, as well as the design of expansions and new structures that complement and respect their surrounding environment. In addition to full architectural services, we offer a diverse portfolio that combines contextsensitive and innovative designs with sustainable strategies. More than 100 projects in the firm’s portfolio have been honored with over 120 awards for quality design, outstanding restoration work, and innovative approaches to adapting existing facilities for new uses. With over two decades of experience, QEA’s professionals combine expertise in renovation architecture with knowledge of the special issues involved in developing context-sensitive new construction. This enables us to renew important cultural landmarks, while maximizing the structure’s economic viability and fostering community pride in the built environment.
washington﹐ dc ann arbor﹐ mi detroit﹐ mi madison﹐ wi www﹒quinnevans﹒com
PROJECT TEAM Quinn Evans Architects in association with Martin/Martin Inc. Quinn Evans Architects Michael L. Quinn, FAIA, Principal-in-Charge Richard Renaud, AIA, Project Manager Alexis Cecil, AIA, LEED AP, Project Architect Martin Martin Inc. - Project Leader John Lund, PE David Wittman, PE Humphries Poli Architects Dennis Humphries, AIA Jane Crisler, AIA, LEED AP
CLIENT State of Colorado Larry Friedberg, AIA, State Architect Office of the State Architect Department of Personnel & Administration 1313 Sherman Street Suite 319 Denver, Colorado 80203
SUMMARY PROJECT DESCRIPTION COLORADO STATE CAPITOL DOME RESTORATION 2015 Palladio Awards Submission – Civic Restoration Preservation In September 2014, after four years of planning and construction, the $15 million restoration of the Colorado State Capitol Dome was concluded with a public rededication. Today considered one of the most important historic buildings in the State of Colorado, the Colorado State Capitol was completed in 1903 after a seventeen year period of construction, and is the defining structure of downtown Denver’s historic public building complex and the public park surrounding it. The project encompassed the comprehensive restoration of the cast iron and sheet metal cladding of the masonry and steel frame circular drum and dome, which rises 172 feet above the main roof of the Capitol building. The dome, having survived for over 100 years, was structurally sound but 100 years of wear left the cast iron and sheet metal skin and 106 windows deteriorated and in need of restoration. The primary goal for the project was to restore the historic dome to its original grandeur and to prepare it for another one hundred years of low maintenance use as the symbol of democracy and public pride for the State of Colorado. The cast iron cladding and gilded copper dome with 106 windows, which brings daylight into the center of the Capitol, had been repaired and painted periodically over the dome’s life, but recent failures of cast iron cladding above the observation platform and patterns of rust staining revealed more serious deterioration which was hidden beneath many layers of paint and caulk. Early investigations also revealed shortcomings in the original design and construction which compromised the dome’s ability to shed rain and stand up to the elements. The dome restoration included the removal and repainting of 100 years of paint as well as selected dismantling and reconstruction of all cast iron surfaces and decorative elements. The glided sheet metal dome roofing was replaced and all decorative sheet metal elements were restored. The project also restored the 106 original wood windows, which allow natural light to flood the historic Capitol interior.
UNUSUAL FEATURES & DESIGN CHALLENGES This restoration represented a special opportunity to employ traditional construction techniques to preserve and restore the original construction while also utilizing state of the art contemporary building technologies to provide a comprehensive restoration and improve on shortcomings of the original design and technologies available 110 years ago. Unusual to the design process, the design team recommended that a significant forensic survey and building evaluation, including selective dismantling and testing of alternative treatments, be undertaken to ensure a thorough understanding of the treatments required and the use of the highest quality restoration techniques. The design team partnered with the Construction Manager and the State Architect to complete this process, which led to a higher quality and more cost-effective project for the State of Colorado. We found a long history of water penetration had led to areas of structural deterioration in the supportive iron framing, as well as the failure of cast iron and the steel fasteners which held the cladding in place. The wood windows were in need of serious repair, and the decorative sheet metal copper dome was compromised by the effects of 100 years of expansion and contraction and patterns of severe weather including hail storms and ice damage. To ensure a quality result, 100 years of paint build up needed to be removed to reveal failures in the cast iron cladding assembly and fasteners and to create a high quality base surface for repainting. Selected areas of cast iron cladding, like built-in guttering, decorative cornices, and ornamental balustrades, had to be dismantled and reconstructed. Broken and deteriorated cast iron elements were shipped to the foundry for repair and/ or recasting. Historic cast iron was manufactured like a kit of parts but the idiosyncratic fit of the original elements had required cutting and fabrication in the field during restoration, replicating the process of the original construction team. We estimate that 98% of the original cast iron was retained in the restoration. The restoration included an aggressive effort to replace the original rusted mild steel fasteners with new stainless steel fasteners. All 106 windows were removed, dismantled, and restored in a controlled shop environment. The sheet metal work on the dome was replaced while all original decorative elements were removed, restored, and reinstalled. The new sheet metal copper roof provides a superior base for the application of the gold leaf gilding which replicates the original dome finish. In selected areas, new structural decking was installed where it was originally omitted to resist future sheet metal failure. New technologies in under-roof waterproof membrane, improved expansion control detailing, and high performance sealant and caulks were carefully planned to ensure a waterproof envelope for the restored structure. The restoration team was challenged to provide good worker access to this project which extended above the main roof of the Capitol building 172 feet. Thirty five tons of specially designed scaffolding was constructed above the Capitol roof and enclosed with a plastic scrim for two years to provide access for the three year restoration process. This restoration represented a major milestone in a multi-decade restoration and renewal process for the Colorado State Capitol Building and it serves as an excellent model for other state capitol structures around the country.
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EAST COLFAX AVENUE
STAGING AREA
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R TE
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SR
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TR TR
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TRAFFIC
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SITE PLAN
TR
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TR
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CR
9 I
H 16' - 8 1/2" ± DECK
8
10
TYP. EJ EJ
EJ
4' - 8 3/4" 1/4" PER FT. (VIF)
EXIST. SLOPE DN
7
J
DECK TYP.
G
11
B.9
EJ
EJ
F
K
B.8
UP
DN ) PE O VIF .( SL FT T. IS ER EX " P /4 1
B.10
6 B.7 B.11
12 EX IST .S LO PE "P DN ER FT . (V IF)
1/4
EJ E
EJ L
B.12
B.6
13
5 DN
EXIST. SLOPE DN
B.13 EJ
EJ
1/4" PER FT. (VIF)
B.5 (ABOVE)
R
24
'-
11
3/4
"±
ROTUNDA OPEN TO BELOW
B.4
D
. C.I
4
14
B.15
3' 6
1/4
OBSERVATION DECK
R3
M EJ
"±
B.3
DN ) PE VIF O .( SL FT T. IS ER EX " P /4 1
B.14
DE CK
EJ
B.16
B.2
EX IS T "P .S ER LO PE FT D .( VIF N )
B.1
C
N
EJ
3
1/4" PER FT. (VIF)
EXIST. SLOPE DN
EJ
15
O
B
EJ
EJ
EJ
16
2 A
P
1
OBSERVATION DECK PLAN
KEY PRODUCTS, MATERIALS & SUPPLIERS Gold Leaf: AngloGold Ashanti w/ Cripple Creek & Victor Gold Mining Company High Performance Coating System: Sherwin Williams Exterior Deck Coating: Dex-o-Tex Copper Roofing Material: Firestone UNA-CLAD Copper Access and Scaffolding: Atlantic Scaffolding Sealants: DOW Corning Sealant
KEY CONTRACTORS, SUB-CONTRACTORS & CRAFTSPEOPLE The project was constructed by the following team: Construction Manager
G H Phipps Construction Inc. Greenwood Village, Colo.
Consulting Construction Manager
The Christman Co. Lansing Michigan
Cast Iron Specialist
Robinson Iron Alexander City, Alabama
Paint Restoration Subcontractor
A G S Construction, Inc Littleton , Colorado
Sheet Metal Roofing Subcontractor
Douglas Colony Group, Inc Commerce City, Colorado
Window Restoration Subcontractor
Lyons Historic Windows Denver, Colorado
Gold leaf Gilding Subcontractor
Evergreen Studios New York , New York
PHOTO 1 Before: An overview of the Colorado State Capitol Building and Dome (DRUM and Dome). 110 years without major renovation, failing cast iron, deteriorated sheet copper dome and deteriorated windows needed comprehensive restoration. The Dome rises 272 feet about grade is major architectural landmark for the State of Colorado.
PHOTO 2 Before: A partial elevation of the cast iron cladding and columns showing water and rust staining at the belt courses which demonstrate more extensive concealed deterioration. Note the safety netting at the upper cornice installed after cast iron failure in 2006.
INSET A
INSET B
PHOTO 3 Design Stage Forensics - Selective dismantling and testing during the design process revealed specific areas of structural deterioration and provided an opportunity for proper material science research to guide the high-quality long-term restoration. Aerial photo - Showing the scaffolding required for detail forensics and documentation during design. Inset A: Removed cast iron cornice face and built in gutter revealed failed structural wrought iron structure. Inset B: Selective dismantling of decorative sheet metal dome confirmed deterioration of sheet metal work, and guided design detailing for improved weather proofing and structural reinforcement in the restoration.
PHOTO 4 During Construction: Removal of 100 years of paint helped to confirm original cast iron assembly and requirements for repair and restoration. Alternate paint removal strategies were tested to determine most cost effective approach for achieving the required bare metal finish for the new high performance painting.
PHOTO 5 During Restoration: Restored cast iron entablature reconstructed and in place. Inset: Failed cast iron entablature above major columns removed for repair and restoration.
PHOTO 6 During Restoration: Upper dome fully scaffolded for construction revealed gilded sheet metal condition compromised by 100 years of harsh weather, hail, and temperature extremes.
PHOTO 7 During Restoration: Showing restoration of the sheet metal roofing. Field sheet metal is replaced with new cooper with improved expansion control. All original decorative elements were removed restored and reinstalled in the reconstruction of dome roofing.
PHOTO 8 After: Overall view of restored cast iron drum and dome with new gilded sheet metal dome structure and lantern.
PHOTO 9 After: Detail view of restored column capitols and the reconstructed cast iron entablature structure.
PHOTO 10 After: Overall night time view of the restored State Capitol Dome with cast iron drum and gold leaf glided dome, one of the most important landmarks in greater Denver and the State of Colorado.
WE SEE A BETTER WORLD The experienced professionals at Quinn Evans Architects are committed to elegance in design and well-crafted solutions that sustain and renew the tradition of our built environment. Quinn Evans Architects (QEA) is a full service architectural firm with offices in Washington, D.C., Ann Arbor and Detroit, Michigan and Madison, Wisconsin. In order to meet our clients’ needs, our comprehensive services include architecture, preservation, interior design, planning, and landscape architecture. Our creative and sensitive design solutions have addressed the renovation and restoration of existing structures and sites, preservation and reuse of important buildings, as well as the design of expansions and new structures that complement and respect their surrounding environment. In addition to full architectural services, we offer a diverse portfolio that combines contextsensitive and innovative designs with sustainable strategies. More than 100 projects in the firm’s portfolio have been honored with over 120 awards for quality design, outstanding restoration work, and innovative approaches to adapting existing facilities for new uses. With over two decades of experience, QEA’s professionals combine expertise in renovation architecture with knowledge of the special issues involved in developing context-sensitive new construction. This enables us to renew important cultural landmarks, while maximizing the structure’s economic viability and fostering community pride in the built environment.
washington﹐ dc ann arbor﹐ mi detroit﹐ mi madison﹐ wi www﹒quinnevans﹒com
PROJECT TEAM Quinn Evans Architects in association with Martin/Martin Inc. Quinn Evans Architects Michael L. Quinn, FAIA, Principal-in-Charge Richard Renaud, AIA, Project Manager Alexis Cecil, AIA, LEED AP, Project Architect Martin Martin Inc. - Project Leader John Lund, PE David Wittman, PE Humphries Poli Architects Dennis Humphries, AIA Jane Crisler, AIA, LEED AP
CLIENT State of Colorado Larry Friedberg, AIA, State Architect Office of the State Architect Department of Personnel & Administration 1313 Sherman Street Suite 319 Denver, Colorado 80203
