Oltmans provided preconstruction and construction services to assist in the relocation of the Ganahl Retail and Lumber Yard in Costa Mesa, the second ever composite wood and concrete rooftop parking structure. The project consisted of 60,000 s.f. of retail space with an exterior skin made of glass and masonry. The facility also included a rooftop parking structure composed of wood and concrete, and over 150 glu-lam beams on a seven (7)-acre site. Other components to the project are a 33,000 s.f. storage and mill shed, a 6,800 s.f. 3-sided pole shed, and numerous racking systems (t-sheds) for additional storage of merchandise.


Oltmans assisted the design team through design development and construction document development, established a GMP, provided cost/value analysis and supported entitlement procurement. Due to a ground lease agreement with the Orange County Flood District (OCFD) and the location at the foot of the I-73 freeway, owned by Caltrans, the Ganahl Lumber Costa Mesa site crosses three (3) entities with jurisdiction including the City of Costa Mesa Building & Planning Department. Substantial coordination was required and a third party consultant was hired to ensure that the entitlement and permitting completed without delay. Within the Caltrans District 12 department alone, Oltmans supported plan check, planning, and entitlement with over twelve (12) different engineers and departments.

Composite Wood and Concrete Rooftop Construction

Each glu-lam beam consisted of up to eight (8) 4”x4” notches that piece together and act as the composite wood/concrete roof structure system. To speed up this process and accelerate the project schedule, the glu-lams were ordered in advance and staged on the storage and mill shed building pad footprint to be used as a workspace for glu-lam beam notching on the ground. The overall notch prepping process took two (2) months on the front end but was able to reduce rooftop erection time to 1.5 weeks at a rate of 20-30 beams a day.

Schedule Recovery

2016 yielded one of the greatest amounts of rainfall in the past decade with the most precipitation falling during site grading and over-ex. At the end of each day, each glu-lam had to be covered and protected from inclement weather and grading was halted until the rain stopped. To recover the schedule, Oltmans successfully worked with Ganahl Lumber to finalize the layout of the retail store early so that the proper underground utilities could be completed to pour the slab on grade (SOG) early. With the SOG completed earlier in the sequence, weather delay was reduced because the slab dried quicker than the compacted dirt. Roof erection also sped up because the SOG allowed for easier maneuvering of the crane, assisting with the hoisting and setting of the pre-prepped glu-lam beams. During relocation from the old store to the new one, Oltmans was also mindful of turnover sequence to minimize Ganahl’s potential revenue/time loss and support the owner’s financial initiatives. Oltmans deliberately turned over the lumber mill in the new store early, so as to prevent any disruption to Ganahl’s service. Orders from the old store were able to be serviced at the new store even during the construction process.

Square Footage

60,000 s.f.