How to build a wood skyscraper

Summary

This video explores the construction of Ascent Milwaukee, the world’s tallest timber building. It explains how mass timber, an innovative building material, is changing construction practices. Key differences between traditional materials like concrete and mass timber are highlighted, from its structural properties to its environmental benefits. The video discusses the challenges and complexities of working with timber, such as design, sourcing, and regulatory hurdles, and emphasizes the collaborative effort needed to build such structures. The final result is a sustainable, aesthetically appealing, and structurally sound building made from wood.

Takeaways

• 🏗️ The Ascent building in Milwaukee is the tallest timber building in the world, standing at 284 feet and 25 stories.
• 🌲 Mass timber, such as glue-laminated timber (glulam) and cross-laminated timber (CLT), is the key material used, offering aesthetic appeal, environmental benefits, and strong structural integrity.
• ⚙️ Mass timber changes the construction process significantly, requiring digital planning, including the use of a Building Information Model (BIM), which functions as a highly detailed 3D blueprint.
• 🔥 Mass timber's fire resistance is demonstrated through tests where the wood develops a protective char layer, with Ascent's columns passing a 3-hour fire test.
• 🌍 The project used timber sourced from Austria, emphasizing global logistics challenges, such as supply chain delays, similar to those caused by events like the Suez Canal blockage.
• 🛠️ Construction with mass timber is cleaner, safer, and faster compared to traditional methods, with less waste and reduced labor requirements.
• 🔩 Workers use battery-operated tools to install screws, and each floor requires around 7,000 screws, minimizing traditional welding and other processes.
• 🌱 Mass timber is seen as a sustainable alternative to steel and concrete, offering environmental credits for builders and a lower carbon footprint.
• 🚧 Mass timber projects require extensive regulatory approval due to their novelty, but they perform well under structural and fire tests, making them viable options for tall buildings.
• 💼 The entire project process, from design to construction, differs greatly from traditional buildings, with more coordination and planning required upfront.

Q & A

What is unique about the construction of Ascent Milwaukee?

Ascent Milwaukee is the tallest timber building in the world, constructed using mass timber, which includes wood slabs, beams, and columns. The structure features exposed timber that is both functional and aesthetic.

Why is mass timber gaining popularity in construction?

Mass timber is strong, environmentally sustainable, and offers aesthetic advantages over concrete. It is also renewable and can help earn environmental credits for builders.

What are some key differences between traditional construction materials and mass timber?

Traditional construction materials like steel and concrete are familiar to builders and regulators, but they are energy-intensive to produce. Mass timber, on the other hand, is lighter, less familiar, and can require more planning due to prefabrication but offers environmental and aesthetic benefits.

What is the role of a Building Information Model (BIM) in the construction process for mass timber buildings?

A BIM is a 3D, highly detailed model used to digitally plan every aspect of the building ahead of time. For mass timber projects like Ascent, BIM helps ensure that everything is precisely designed and prefabricated, reducing the risk of delays and errors.

How does the prefabrication process change the construction of mass timber buildings?

Mass timber buildings are largely prefabricated in factories, meaning that if there is a mistake, it can cause significant delays. This requires extensive planning and coordination before the construction phase begins.

How do timber columns perform in fire resistance tests?

Timber columns, when exposed to fire, form a char layer that protects their structural stability. In tests for Ascent Milwaukee, the timber columns were rated fire-resistant for up to 180 minutes, surpassing regulatory requirements.

What are the sourcing challenges for mass timber used in projects like Ascent?

Mass timber often has to be sourced internationally, as was the case with Ascent’s wood, which came from Austria. This requires careful logistical planning due to the long shipping distances and potential disruptions, such as delays in shipping channels like the Suez Canal.

What are the labor differences between constructing with concrete versus mass timber?

Construction with mass timber generally requires fewer workers and generates less dust and waste. Timber is easier to assemble, often reducing the time required for tasks compared to concrete construction, and the use of cordless tools means workers have cleaner work environments.

How does the environmental impact of mass timber compare to traditional materials?

Mass timber is considered more environmentally friendly than concrete and steel because it is renewable and has a lower carbon footprint. Additionally, timber buildings can earn builders environmental credits, and the materials are easier to transport due to their lighter weight.

What are the practical challenges of working with mass timber?

One challenge is the precision required during prefabrication, as mistakes in measurements can lead to significant delays. Another challenge is sourcing, as materials often need to be shipped from long distances, which introduces potential logistical issues.