Join Our Email List

Subscribe

    Join Our Email List

    Subscribe

    Media Inquiries

    Randy Paulson

    Director of Marketing

    Call 949-234-6031

    Email ›

    Back to recent Share This

    Fix It Friday: Saving the “Face” of the Historic Boston Building in Denver, CO

    Walker Restoration Consultants is in the business of “saving places” and we recently had the opportunity to help save one of downtown Denver’s oldest buildings!

    The History

    The Boston Building is located on the southeast corner of 17th and Champa in the middle of Denver’s financial district.  The historic mid-rise 9 story building faced with Greenlee red sandstone quarried near Manitou Springs, CO, was constructed in 1890. The project was financed by Henry R. Wolcott who engaged the design services of Andrews, Jacques and Rantoul of Boston, MA. It was known as the 1st “Strictly Modern Office Building” to be erected in Denver, CO.

    Picture2
    The building is a combination of Renaissance Revival and Richardson Romanesque architecture.

    The building attracted prosperous and progressive tenants including:

    • Ralph Voorhees
    • Claude K. Boettcher
    • Postal Telegraph and Cable Co.
    • Colorado Midland Railroad Co.
    • Denver Water and Land Storage
    • Aetna Insurance Co.

    The building has undergone repairs and changes throughout its life. The roof was originally embellished with a narrow but elaborate cornice with carved heads spaced along the soffit. Below was a narrow frieze of rusticated sandstone. Between the 6th and 8th floors there were decorative string courses, a red sandstone balcony with balustrade over the top of the 3 entrance arches, and rusticated stones at base.

    The Structure

    The building’s structure is wood floor joists, supported by wood and steel beams with masonry bearing walls. Exterior walls are solid sandstone blocks stacked up to 4’ thick, with individual blocks ranging from 2’ thick at the base to 5” thick at the parapet on 2 sides of the masonry block.  On the other 2 sides, solid sandstone lintels or sandstone block arches are spanning all exterior window/door openings.

    Picture4

    The Road to Bringing the Boston Building Back to Life

    Walker Restoration performed a Condition Appraisal, which included:

    • Determining the cause of stone pieces falling on the sidewalk
    • Establishing the current condition of the building façade
    • Identifying, locating, and illustrating deterioration and/or failures on building elevations
    • Performing material testing to determine deterioration causes
    • Assessing findings in order to present and prioritize repair, maintenance, and upgrade recommendations
    • Developing the construction documents and providing construction administration during the restoration

    Observations & Findings

    Items Observed

    • Failed, mismatched, and deteriorating existing patches
    • Failed joints
    • Structural lintel cracks
    • Deteriorating sandstone
    • Dirt and water stains
    • Pigeon roosts
    • Parapet walls & flashing
    • Deteriorating wood frames

    Picture10    Picture7

    Picture5     Picture6

    Research Findings

    • Greenlee sandstone was quarried near Manitou Springs, CO
    • Stone: soft, medium grained red sandstone with iron oxide material properties
    • Iron oxide is the prominent binding material in this type of sandstone which creates the warm red color
    • Oxidation (rusting) of the iron in the stone has caused disintegration and a loss of the cohesive binder
    • Material testing revealed that this stone is very absorbent, making it susceptible to saturation and freeze/thaw damage

    Appraisal Findings

    • Approximately 75% of the detail and corner conditions and 10% of the flat surfaces experienced deterioration
    • Small portions were at risk of falling from the building
    • Bedding planes of sandstone are natural lines of weakness
    • Water is more likely to split stone if set with the bedding planes in a vertical fashion

    Picture17   Picture18

    Deterioration Mechanisms

    • Freeze/Thaw action
    • 6.3% absorption characteristic holds water
    • Ledges and detailed pieces suffer most damage due to collection of water

    Identified Repairs

    • Sandstone Repair
      • Removal of loose, flaky and deteriorated stone
      • Modify ledge conditions
      • Patch material
      • Structural crack repairs
      • Anchoring
      • Tuck-pointing
    • Waterproofing and Sealants
      • Sealants
      • Flashing
    • Cleaning
      • Correct method/product
    • Sealing
      • Consolidant vs. Siloxane

    CDCD 2

    Ongoing Recommended Maintenance

    Walker recommended ongoing repairs and maintenance every 3 to 5 years. Some recommendations included:

    • Sandstone Façades
      • Observe for additional unsafe or deteriorating conditions annually
    • Brick Façades – Repairs may last 8 to 10 years
    • Wood Trim – Paint may last 8 to 10 years
    • Waterproofing – Sealants may last 10 to 12 years

    Picture15

    The Finished Product

     

    Picture3

    Picture19 Picture16

    Today the building has been converted into premium apartments now known as the Bank and Boston Lofts!

    For more information on this project, please reach out to Leo Whiteley, PE, LEED AP.

    Leo Whiteley with jacket 2015

     

     

    How can we help today?

    Get In Touch ›