STRUCTURAL INFORMATION

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Understanding why structural systems fail—and how they can be repaired—is critical to protecting buildings, operations, and long-term investments.
SPS provides engineered evaluations and repair solutions for aging, damaged, or overstressed structural framing systems commonly found in commercial and industrial buildings throughout California.

From the 1920s through the early 1950s, bowstring trusses were widely used as primary roof framing systems. Beginning in the early 1950s, glue-laminated (glulam) beams became the predominant structural element in commercial and industrial construction and remain in extensive use today. Tapered steel girders with rafters or panelized roof decks were also common in mid-century buildings.

Over time, these systems may experience deterioration or failure due to a combination of age, loading changes, and environmental conditions. Common causes include:

• Overstress from added long-term dead loads, such as multiple roof layers
• Added equipment not included in the original design (HVAC, sprinklers, ceilings, lighting, crane rails)
• Fabrication or material defects, including timber flaws and glue-line failures
• Exposure to moisture, chemicals, or extreme heat
• Long-term material fatigue
• Seismic loading
• Forklift or vehicle impact in warehouse facilities
• Improperly installed mechanical equipment
• Limitations or oversights in original structural design

Due to the documented history of failures in these framing systems, modern building codes have reduced allowable fiber stresses for wood members and introduced volume adjustment factors.

These code changes provide a more accurate representation of true material capacity and are essential when:

• Evaluating existing structural members
• Designing repairs or reinforcements
• Adding new loads to older buildings

Repairs to roof trusses, glulam beams, and other horizontal framing members require engineering analysis and site-specific design. Repair approaches vary depending on member condition, loading, and accessibility.

• Broken or damaged members can often be repaired in place and restored to full design capacity
• Overstressed members can be strengthened to safely support existing or added loads
   

SPS develops repair solutions that are structurally sound, constructible, and cost-effective, with minimal disruption to building operations.

SPS employs a range of proven structural reinforcement techniques, including engineered post-tension systems using steel tension rods or high-strength cables. These systems are designed to increase both bending strength and shear capacity of existing members.

Additional methods may include:

• Epoxy-installed shear dowels
• Supplemental steel reinforcement
• Custom design-build solutions tailored to site constraints

•  More economical and less disruptive than member removal and replacement
• Original clear spans are maintained—no added columns interfering with operations
• Repairs are often performed from below, preserving existing roof system 
• Roof warranties remain intact
• Effective in tight or congested spaces around sprinklers, ductwork, crane rails, and ceilings
• Many single-member repairs can be completed within one day
• Construction procedures are designed to minimize business interruption

 SPS post-tension systems allow existing framing members to safely support loads beyond their original design capacity. Structural reinforcement can:

• Support new HVAC units, ceilings, sprinklers, and mechanical equipment
• Enable building use conversions (warehouse to office or cold storage)
• Correct fabrication or design deficiencies
• Address changes in building code requirements
• Eliminate beam sag and reduce roof ponding
• Restore capacity to fire-damaged glue-lam beams