Repairing structural and aesthetic concerns during the restoration and expansion of a 230,000-square-foot tobacco curing and processing complex
Caretti Restoration & Preservation Services, Inc.
Benchmark Construction Co.
As part of the $11.5 million expansion and renovation for Lancaster, Penn.-based Lancaster Leaf Tobacco Company, Inc.'s deteriorating 230,000-square-foot tobacco curing and processing complex, many of the early 1900’s tobacco warehouse structures at the Pitney Road complex are being preserved. This includes the structural restoration of a 5-story warehouse on the southwest corner of the campus.
A 40-foot by 50-foot section on the east elevation of the warehouse had collapsed in the summer of 2011. Caretti Restoration & Preservation Services, Inc., Camp Hill, Penn., conducted a detailed inspection on the remaining masonry facade to determine the best implement of repair for the severe structural issues. The inspection revealed that a triple wythe of bricks was coming apart and the header courses that tied the walls together were not intact. In addition to the building’s age, deterioration occurred because it was a concrete superstructure with brick infill that expands when it gets wet and pulls the concrete apart.
Caretti Restoration’s General Manager and Vice President Bob Gensel enlisted leading industrial masonry repair reinforcement system manufacturer Helifix, Inc. to implement a strategic combination of its precision engineered Crack Stitch and DryFix systems in early October of 2011. The DryFix Remedial Pinning and Tying System provides a stress-free retrofit connection between all commonly used building materials. Because both the Crack Stitch and DryFix systems are installed into the existing masonry, expensive and time consuming tear down and rebuild were avoided while retaining the visual aesthetics of the structure.
The Crack Stitch system repaired vertical cracks on the building’s corners to solve key structural and aesthetics concerns. The system allows contractors to repair and redirect stresses on damaged masonry areas, and create a monolithic point to distribute loads. The project used approximately 300 lineal feet of HeliBar to repair vertical cracking in the brick masonry for numerous focus locations of the tobacco warehouse.
The Dryfix remedial pinning and tying system was used for tying the wythes of bricks together to the walls and also for repair of the corroding, loose and missing steel shelf angles supporting the brick veneer for all damaged areas of the warehouse’s five stories.
“The savings on shelf angle repair alone was significant as the per window / per foot cost was about 1/3 less than other methods,” said Chris Devitry, construction manager for the project’s general contracting firm Benchmark Construction Co.
The project used approximately 6,400 DryFix helical anchor ties throughout key focus areas of the tobacco warehouse’s north, south and west elevations. Also, roughly 1,800 lineal feet of shelf angles were repaired using the system at a 3.5-inch by 3.5-inch angle for every floor at the top of the windows to support the brick masonry above.
Installation procedures for the Crack Stitch and DryFix systems were particularly advantageous given the inclement fall-winter weather restoration schedule.
DryFix installation involved power-driving the precision engineered, slim profile remedial ties into position via a small pilot hole. A special installation tool left the end of the tie recessed below the outer face to allow an ‘invisible’ finish. High performance Helifix polymer grout was used in key areas to help increase the bond.
Crack Stitch installation involved cutting/raking out slots in the mortar beds which were then vacuumed and flushed out with water. A Helifix pointing gun was used to inject a bead of thixotropic cementitious HeliBond grout along the back of the slot. Using a brick jointer, one meter length of HeliBar was pushed into the grout to obtain good coverage. A further bead of HeliBond was inserted over the exposed HeliBar, finishing ½ inch from the face and ‘ironed’ into the slot using the brick jointer. The recessed HeliBar was then pointed over the top rendering it virtually transparent to the naked eye upon completion.
With the combined use of Helifix’s concealed, non-disruptive Crack Stitch and DryFix systems, the completion of the restoration of the Lancaster Leaf Tobacco Company was completed on schedule in January of 2012.