Helical anchor and fixing repairs in successful restoration

Helifix helical installation

Faced with the possibility of moving its’ deteriorating 230,000 square-foot tobacco curing and processing complex in 2009, the Lancaster Leaf Tobacco Company, Inc. (Lancaster, PA) embarked on an $11.5 million expansion and restoration project to modernize its’ tobacco-processing operation and save nearly 120 jobs. A subsidiary of Universal Corporation (NYSE: UVV), Lancaster Leaf’s revitalization advancements are poised to make it one of North America’s largest processors of dark, air-cured tobacco and stimulate job growth in the regions’ future.

Suspect super structure

As part of this renovation, many of the early 1900’s tobacco warehouse structures at the Pitney Road complex are being preserved vs. replaced, including the recent structural restoration of a 20-story warehouse on the southwest corner of the campus. Notably, a 40’ x 50’ section on the east elevation of the warehouse had collapsed in the summer of 2011. Immediately, a detailed inspection was done on the remaining masonry façade by Caretti Restoration & Preservation Services, Inc. (Camp Hill, PA), 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 vs. a steel-based superstructure.

Synergistic system solution

To avoid the costly and time consuming replacement and reinstallation of the damaged concrete superstructure, Caretti Restoration’s GM/VP, Bob Gensel, enlisted leading industrial masonry repair reinforcement system manufacturer Helifix®, Inc. (Streetsboro, OH) to implement a strategic combination of precision engineered Crack Stitch and DryFix systems in early October of 2011.

Helifix’s Crack Stitch system was utilized predominantly for repairing vertical cracks on the building’s corners to solve key structural concerns and also for aesthetics. Helifix’s 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 20 stories.

DryFix profile

Approximately 6,400 DryFix helical anchor ties were used 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” x 3.5” angle for every floor at the top of the windows to support the brick masonry above.

Developed by Helifix®, Inc. over many years, the patented DryFix Remedial Pinning and Tying System provides an effective, economical, and stress-free retrofit connection between all commonly used building materials. The slim profile, precision engineered DryFix helical ties (stainless steel; grade 304 or 316) are made from a drawn stainless steel manufacturing process that creates the helical hi-fin design that more than doubles the proof stress. With its’ relatively small diameter, the system provides substantial tensile properties to the concrete.

Ideal for both cavity and solid masonry constructions, the DryFix system requires no special grouts, resins, or mechanical expansion, and is embedded within the existing masonry to be fully concealed−once installed.

Crack Stitch profile

Approximately 300 lineal feet of HeliBar was utilized to repair vertical cracking in the brick masonry for numerous focus locations of the tobacco warehouse.

Helifix’s Crack Stitching system is a cost-effective means of permanent crack repair, that is ideal for restoring the structural integrity and permanent repair of older cracks.

The system allows contractors to repair and redirect stresses on damaged masonry areas, and create a monolithic point to distribute loads. This is achieved by combining stainless steel (austenitic grade 304) HeliBar reinforcement rods with injectable, non-shrink cementitious HeliBond grout−producing a high compressive strength.

Once installed to the channeled-out mortar beds, the HeliBar rod’s hi-fin design delivers substantial axial strength while providing flexibility across the crack to accommodate natural building movement.

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. This effective combination made the systems ideal for the Lancaster Leaf Tobacco Company’s structural warehouse restoration project.

Ease-of-use, cost-effective, cold weather installation

Helifix’s Crack Stitch and DryFix systems also provide quick, user-friendly, and cost-effective installation procedures. This was particularly advantageous given the inclement Fall-Winter weather restoration schedule for Lancaster Tobacco Company’s warehouse, since most mortar installations can’t be done in colder months.

DryFix installation involves simple power-driving of the precision engineered, slim profile remedial ties into position via a small pilot hole. A special installation tool is then used to leave the end of the tie recessed below the outer face to allow an ‘invisible’ finish. High performance Helifix polymer grout was utilized in key areas to help increase the bond.

Crack Stitch installation involves cutting/raking out slots in the mortar beds (minimum 20” either side of the crack) which are then vacuumed and flushed out with water. A Helifix pointing gun is then 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 is pushed into the grout to obtain good coverage.

A further bead of HeliBond is inserted over the exposed HeliBar, finishing ½” from the face and ‘ironed’ into the slot using the brick jointer. The recessed HeliBar is then pointed over the top rendering it virtually transparent to the naked eye upon completion.

Tobacco Warehouse conclusion / results

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.

Implementation of the same dynamic repair combination is being planned for additional buildings on the Lancaster Leaf Tobacco campus.

Chris Devitry, Construction Manager for the project’s general contracting firm Benchmark Construction Co. (Brownstown, PA), noted the combined system’s cost-efficiency, “The savings on shelf angle repair alone was significant as the per window / per foot cost was about 1/3 less than other methods.”

According to Caretti Restoration’s GM/VP, Bob Gensel, “You don’t often have a complete wall collapse on a masonry façade so this represented pretty severe structural deterioration. Ultimately, combining Helifix’s Crack Stitch and DryFix systems was the ideal alternative to complete structural tear down and rebuild of the Lancaster Leaf Tobacco Company’s warehouse.”