The ins and outs of pre-fabrication from a mass timber manufacturer
By Stephen Tolnai vice-president Structurlam
Jan. 26, 2017 - Whether the structure you’ll be erecting is something that has been built a thousand times, or if it is a one-of-a-kind masterpiece, an efficient and cost-effective construction process is heavily dependent on how well-organized and prepared your trades are. Major construction projects find multiple trades working in conjunction, and one crucial way to ensure success is to incorporate pre-fabrication into the process.
Mass timber manufacturer Structurlam Products is a Penticton, B.C.-based company that uses pre-fabrication in every project it undertakes. The company champions this process because they find it results in cost savings for clients, fast on-site assembly, safer work sites and an opportunity for higher quality structures.
Preparation is key in pre-fabrication
The important first step in pre-fabricating the pieces that will ultimately be put together to form a building is the creation of a 3D model. Mocking up the building exactly as it will need to be created — also known as virtual construction — from the walls, to the holes for plumbing and electricity, is a means of testing and fine-tuning the details to ensure everything is in place before anything is produced and sent to site. Structurlam advocates that all trades use a single geometry model during this process, as it reduces confusion and saves time for all involved. Once the modelling is underway, Structurlam can make adjustments to the building as needed to allow for tolerances and fabrication details.
Once the 3D model is complete, the customized data can then be used to create a list of materials that are needed, the exact shop drawings can be completed and then the pre-fabrication of the pieces can begin. The modelling work results in a process that creates the CNC machine codes for the geometry needed to produce each unique panel. This begins what will ultimately make completing the building akin to putting together a dresser from IKEA.
“At Structurlam we work closely with all trades involved to ensure everything that will go into the building is reflected perfectly in the 3D model,” said president of Structurlam Bill Downing. “Our ability to incorporate every detail into the pre-fabrication process allows us to deliver the pieces to a building that will come together smoothly and benefit all who are working together to erect it.”
Upon completion of the individual pieces, these fabricated panels are placed in order of delivery to the site. They are loaded on to the trucks perfectly to match the installation sequence. While this requires a tremendous amount of pre-planning, it is what results in the time and cost savings for the project and allows for buildings to be erected in high-traffic, small footprint areas, as there is no material stored on site.
Tall wood and pre-fabrication
Pre-fabrication is an essential element the construction of mass timber buildings. For example, this process was utilized at the recently completed Brock Commons at UBC, the world’s largest tall wood building. The 18-storey mass timber structure will be a student residence building, housing more than 400 students when it is completed in May 2017.
Structurlam provided 169 mm, 5 layer CLT panels measuring 2.9 x 11.8 m for floors, along with glulam columns for the building’s interior. Steel connectors allowed the building to be put together quickly and safely. The steel connectors allowed for a direct load transfer between columns and also provided a bearing surface for CLT panels. The seamless construction of this record-breaking project was well served by pre-fabricating the pieces.
Benefits of pre-fabrication
Pre-fabrication can be realized for any size or scope of project, from record-breaking towers to multi-family homes in dense urban areas; no matter the project the benefits will be the same:
· Fast assembly: Perfect pieces delivered in order allows for an efficient and quick assembly; this can minimize the total schedule duration of a project.
· Cost-effective: Pre-fabricating the pieces reduces waste and allows for a fast assembly, cutting down on costs and encouraging efficiency across the trades.
· Safer work site: Many tasks are accomplished in Structurlam’s shop, removing the need for complicated work to be undertaken on site or at jarring heights.
· Reduced labour on site: Prefabrication ultimately requires less people on site to install the structure.
· Higher quality: Critical elements of the building are completed in a controlled shop environment.
An organized and efficient construction site is ultimately dependent on how well the trades involved work together. Incorporating pre-fabrication supports these efforts and encourages collaboration and close working relationships from the onset of the project. Utilizing the impressive power of pre-fabrication serves projects of all sizes and delivers tremendous benefits across the board.