Updates from GNCB

Wood Cantilever Repair of National Register House using ConServ Epoxy

  • By GNCB
  • 17 Jul, 2017

Orange, CT

The reconstruction of the second floor balcony around the perimeter of 30 Derby Avenue in Orange, CT was recently completed. 30 Derby Avenue, also known as the Henry F. Miller House, is an example of international style architecture and is on the National Register of Historic Places. The second floor balcony, which was severely deteriorated due to water infiltration, exemplifies three characteristics of international style architecture including the integration of structure and site, taking advantage of the climate, and providing simple aesthetic features. GNCB provided a condition assessment, construction documents, and construction administration for this project which reestablished the balcony structure and perimeter railing.

The damaged double-cantilever structure of the balcony was reestablished using glass fiber-reinforced polymer (GFRP) rebar and a ConServ Epoxy restoration system. The damaged cantilevers were cut back an acceptable surface and the GFRP bars were doweled into the existing timbers and the new timbers. The bars and timber faces were prepared using ConServ 552 Epoxy, a multipurpose structural epoxy adhesive. Paul Marlowe of Marlowe Restorations LLC and the owner of ConServ Epoxy LLC, conducted the cantilever reconstruction process. The railing design by Christopher Williams Architects replicated the original railing from available photographs.

Architect: Christopher Williams Architects, LLC

Contractor: Marlowe Restoration LLC

Supplier: ConServ Epoxy LLC

Photograph of the original balcony at the rear of the House, courtesy of the Henry F. Miller National Register Nomination package.
Condition of the rear and side balconies at the time of GNCB’s condition assessment. The original decking and railing had collapsed and the original structure was severely deteriorated and temporarily shored in some locations.
GNCB’s timber repair design used GFRP dowels to develop the tension forces within the 4’-3” long cantilever. The faces of the spliced timbers and the GFRP bars were prepared using ConServ 552 structural epoxy adhesive. The design lengths shown were extended at some timbers to accommodate varying field conditions.
The deteriorated double cantilevers were cut back to an acceptable surface. Where timbers were deteriorated at the face of the building, the surface were repaired with ConServ Epoxy Consolidant 100 and Epoxy Patch 200 prior to installation of the GFRP bars.
The GFRP and wood surfaces were prepared with ConServ 552 Epoxy.
The new timbers were clamped in place to allow the ConServ formulas to cure.
The new wood timbers were constructed to match to profile of the original timber cantilevers.
The completed second floor balcony is a replication of the original structure, decking, and railing of the Henry F. Miller House.
By GNCB 17 Nov, 2017

GNCB attended the ribbon cutting ceremony for the Sayebrooke Village Elderly Housing Expansion project this month. The project broke ground earlier this year and now contributes an additional 15 units to the highly popular complex on Sheffield Street.

The buildings are a mixture of single- and two-story wood-framed structures on concrete slabs-on-grade. GNCB provide structural engineering and geotechnical engineering services for the project. The expansion was a Connecticut Housing Finance Authority (CHFA)-funded project.

Architect: Wiles + Architects

Contractor: Haynes Construction

By GNCB 14 Nov, 2017

Ms. Zoe Laird of Ohio has been hired as a Design Engineer at GNCB. Ms. Laird graduated from the University of New Haven (UNH) this May with a Bachelor’s of Science in Civil Engineering.

As a student, Ms. Laird was an active member of UNH’s student chapter of the American Society of Civil Engineers’ (ASCE) Concrete Canoe team, and was a member of the student chapter of the Society of Women Engineers (SWE).  

Ms. Laird’s senior design project was to design a four-story steel-framed boutique hotel with an underground reinforced concrete parking garage for UNH’s Hospitality and Tourism department. She performed much of the structural analysis and structural design for the building, and performed hand calculations to verify the computer model.

Past work experience includes an internship with the Ashtabula County Engineer’s Office in Jefferson, OH; tutoring entry-level engineering courses at UNH; acting as counselor for Camp GEMS (Girls in Engineering, Math, and Science) at Ohio Northern University; and several summers at YMCA Camp Fitch holding various positions including Tech Focus Counselor.

By GNCB 30 Oct, 2017

Amy Jagaczewski , GNCB Engineer, attended this year’s Association for Preservation Technology International (APTi) Conference in Ottawa, Canada . This year’s conference, themed CAPITALizing on Heritage, was a joint conference between APTi and The National Trust of Canada in honor of Canada’s 150th Anniversary. Approximately 1100 delegates from over 20 countries attended, including engineers, architects, preservationists, owners, historians, students, craftspeople, and technicians.

The APTi Conference offered professional development opportunities sorted into seven tracks depending on attendees’ backgrounds and interests. Ms. Jagaczewski attended presentations on the investigation, analysis, planning, and design of heritage structures as well as case studies on successful implementation of structural and preservation engineering principles. Topics directly corresponding with current GNCB work included reversibility of retrofits for exposed structural framing, management and assessment of historic coastal structures, and practices for analyzing unreinforced masonry buildings in moderate seismic zones.

By GNCB 18 Oct, 2017

The Northampton Community Arts Trust began occupying their newly renovated building at 33 Hawley Street in Northampton, MA this fall. The prefabricated metal building was originally built in the late 1980s and required structural upgrades to support the new use and energy-efficient design. The 25,000 square foot building will be used by the Trust to support education, rehearsals, and performances for varying forms of art.

GNCB provided structural engineering and geotechnical engineering services for this project during the initial investigation, design phases, and construction phases. Structural work included supporting new design features as well as addressing deficiencies in the existing gravity and lateral framing systems for modern loads. Geotechnical investigations included interior soil excavations to confirm the layout of existing foundations and subsurface characteristics for the installation of a new elevator pit.

Improvements to the roof framing involved the addition of 50-foot long steel trusses supported on new steel columns at the centerline of the building. The new steel off-loads the original steel bent frames to meet modern building loads and allow the installation of solar panels and a future suspended catwalk system for the black box theater. Steel x-braces were installed between the new and existing perimeter building columns to improve the building’s lateral system. GNCB also provided structural designs for the monumental stair and mezzanine and the new front entrance vestibule.

Architect: Thomas Douglas Architects

Contractor: D.A Sulivan & Sons, Inc.

Steel Fabricator and Erector: Dublin Steel Corporation

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