Attachments.pdf

SPECIAL PROJECT SPECIFICATION

BOWERMAN BARN REPAIR DIVISION 1 01010 - 1

SECTION 083613

BOWERMAN BARN REPAIR

PART 1 – GENERAL

1.01 SCOPE: The work of this Contract is to repair a timber frame connection of Bowerman Barn; to evaluate the rest of the connections to determine if other connections are solid or need repair; and to make recommendations on ways to mitigate other issues found during the evaluation.

1.02 BACKGROUND: Bowerman Barn is timber frame building built in 1878 that is listed on the National Register of Historic Places. While painting in 2011 it was noticed that one of the timber frame connections slipped and is in need of repair. The frame connections are believed to be kept together by concealed wooden dowels. In the early 1990s the structure was evaluated (see attached plans) and cable “X” bracing was added to help support the building when lateral loads were applied. One of the connections where an internal beam is supported by a perpendicular beam at the external wall is supported by column. One of the “X” bracing cables was attached to one of the beams.

At this location, the upper beam has shifted with respect to the supporting members roughly one foot (see attached connection photos). It is unknown if the shift of the beams was due to over tightening of the cables that might have caused the dowel to have been sheared through or if due to the age of the connection, the connection has failed for some other reason and that this connection may be an indicator of what may be happening or about to happen in other timber frame connections. A Restoration Plan and Structural Analysis was conducted by an Engineering Consultant in 1993, and is available to assist the Contractor (see attached Description of structural members and connections).

1.03 WORK: The work is broken in to three main parts.

A. Repair Existing Connection: Contractor is to re-align the timber frame connection that is out of alignment described above and provide a positive connect that will keep the beams from shifting with respect of one to another. The materials/devices used must be in keeping with the historical nature of the building; submitted to and approved by Contracting Officer; and approved or be able to be approved by the State Historic Preservation Officer.

B. Evaluate Entire Building: Contractor is to evaluate the entire structure to determine what repairs and or modifications would need to be made to allow for the structure to be used as a working barn and areas open to the public. Evaluation shall include but not be limited to checking other existing timber connections to ensure positive connections, the stability of the foundation, rodent hole issues, realigning the braced walls on the South side of barn, bug damage to wood members and dry rot.

BOWERMAN BARN REPAIR DIVISION 1 01010 - 2

C. Recommendations: Provide a summary report on the evaluation portion of the contract identifying each area reviewed and the concerns/issues that were identified.

If no issues or concerns were identified in an area, still state the area evaluated and method how evaluation was made. Areas with issues or concerns should include but not be limited: level of employee/public safety at risk; level of risk to the historical building; options for correcting the concerns/issues and mitigating the risks;

providing a recommendation in resolving the concerns/issues considering employee’s/public’s safety, historical nature of building and costs of repairs; and providing an estimate of cost to make the recommended repairs.

1.04 CONTRACTOR: Contractor shall meet the following requirements or have a sub-contractor(s) who meets the following requirements.

A. Contracting license from State of California.

B. Member of Timber Framers Guild and/or Timber Frame Business Council, minimum two years.

C. Minimum seven years timber frame experience.

D. Minimum two projects rehabilitating existing timber frame structures.

E. Minimum two successful projects working with California State Historic Preservation

Officer (SHPO) F. The team must include a licensed engineer (licensed in the state they primarily work) that specializes in the structural integrity of timber frame buildings.

1.05 CODES AND STANDARDS: The work shall be done in accordance with the most recent International Building Code (IBC), the California State Historic Preservation Officer’s requirements and the Secretary of the Interior’s Standards for the Treatment of Historic Properties, 1995. The Secretary of the Interior’s Standards may be found at http://www.cr.nps.gov/local-law/arch_stnds_8_2.htm

1.06 SUBMITTALS: The contractor shall submit a full work plan to the Contracting Officer for review and approval. The work plan shall indicate all type of materials and products used along with the methods needed to perform the work. Any changes to the materials / products or methods used that were not included in the approved work plan shall be submitted for review and approval.

A. In House Forest Service Review: The government will review all submittals within two weeks of the submittal and notify the contractor of approval or disapproval.

B. State Historic Preservation Officer Review (SHPO): Where the Forest Service determines that submittals are of a nature that would be beneficial to get SHPO concurrence/approval, the submittals will be sent to SHPO within two weeks of the Forest Service receiving the submittal. This will allow the Forest Service to review and comment on the submittal prior to sending it off to SHPO. It is unknown how long SHPO will take to provide concurrence or approval. The contractor should be prepared for SHPO to take a long time to review submittals. As such, the initial work http://www.cr.nps.gov/local-law/arch_stnds_8_2.htm

BOWERMAN BARN REPAIR DIVISION 1 01010 - 3

plan should include all items that may need SHPO consultation so submittals to SHPO once work has begun become unnecessary.

1.07 PRODUCT HANDLING: Comply with the manufacturer’s handling recommendations and protect all materials from damage until the work is complete, the project has had a final inspection and the Contracting Officer has accepted the work.

1.08 LOCATION: The Bowerman Barn (40˚ 54' 00.1" N, 122˚ 46' 0.42" W; Elevation 2450 feet) is located on Guy Covington Drive off of Highway 3 approximately 23 miles North of Weaverville, CA.

1.09 GOVERNMENT FURNISHED: Water and Power are not on the site.

1.10 WORK COORDINATION: The work shall be coordinated with the Contracting Officer.

1.11 MEASUREMENT AND PAYMENT: The measurement will be by the completed job and payment will be on a Lump Sum Unit Basis AS SHOWN ON THE SCHEDULE OF ITEMS. Such payments will be considered full compensation for providing all equipment, tools, labor and incidentals necessary to repair the timber frame connection and evaluate the remaining connections.

ITEMS:

01010 (01) Bowerman Barn Repair and Evaluation .....................................LS

PART 2 – PRODUCTS

2.01 All products are to be of a similar nature as originally used in the construction of the structure unless submitted to and approved by the Contracting Officer.

2.02 Where modern connections or materials are recommended by the contractor, the contractor shall submit all recommendations before any work begins to allow for review and possible submittal to SHPO.

PART 3 – EXECUTION

3.01 INSTALLATION: Install all products in a manner consistent with the manufacturers’ recommendations and the historic nature of the building.

3.02 EVALUATION: Evaluate the existing timber frame connections in a manner that does not cause a permanent detraction to the historic nature of the structure.

3.03 SAFETY: The Contractor is solely responsible for the safety of the workers and all others that may be affected by the work.

BOWERMAN BARN REPAIR DIVISION 1 01010 - 4

END OF SECTION

Bowerman Barn Connection Photos

Exterior Rear of Barn

Exterior Rear of Barn

Location of connection needing repair

Location of connection needing repair

Exterior View of Connection Needing Repair

Interior View of Connection Needing Repair

Plate above beam supporting bottom of siding located above beam

Column supporting the end of exterior of beam

Top of siding below beam attached to exterior beam

End of interior (roof) beam sticking out about 12” to 18” of supporting (exterior) beam

Exterior beam

End of interior (roof) beam sticking out about 12” to 18” of supporting (exterior) beam

Column supporting the end of exterior of beam

Exterior beam

Roof beam

Cable attached to exterior beam

Bowerman Barn Photos

Front of Barn

Side of Barn

Side of Barn

Inside of Barn