Shedding Light on "Light Showers" | the skinny

February 9th, 2012

Unique design inspires us. Unusual challenges let us flex our thinking, design, and planning muscles; both at the outset and throughout the project’s duration to overcome inevitable obstacles. These projects also demonstrate the type of company we are and the calibre of people who make up the Heavy team. We will never walk away until the job is done, the right quality level has been attained, and our client is pleased with the result.

For the Heavy team, Light Showers by artist Jill Anholt was one of these challenging projects that has resulted in a stunning execution of Jill Anholt’s vision, though not without learning opportunities along the way.

Jill Anholt is a Vancouver-based artist who focuses on works in public spaces. Her artwork is complimented by her background in architecture. Environmental sustainability plays a generative role in conceptual development, form, and material expression of many of her works, as it did with Light Showers. To learn more about Jill’s work, please visit the Jill Anholt Studio website here.

Concept by Jill Anholt Studio

What is Light Showers?
The completed artwork is a series of three 30-foot tall iconic concrete structures with stainless steel insets integrated into the landscape of the new Sherbourne Common along Toronto’s waterfront, a space that has been recognized as one of the “Best New International Parks”. The forms are a visual expression of the surrounding community’s aspirations to sustainability. The sculptures celebrate collected and purified community storm water by elevating it before the water falls as textured veils into a channel that returns it to Lake Ontario. As people move around the artwork, integrated motion sensors trigger shifting light patterns in the water to illustrate the connection between local actions and distant effects.

How was it Made?
As sustainability plays a role in Jill’s work, Heavy’s moulds were made to be reusable, allowing all three massive concrete elements to be cast from the set of moulds. To create these moulds, we initially worked from a computer model to precisely machine the positive forms using our CNC equipment before laboriously hand-finishing the forms for a consistently smooth surface. From these forms, strong and reusable fibreglass moulds were created. Wooden frames were built to support the massive moulds and keep them level when the concrete would be poured. Release valves were integrated directly into the fibreglass moulds to assist in the de-moulding process. CNC cut templates were laid into the moulds to create space for the steel strips, which would be installed towards completion of the project.

Here are sequential progress photos of Light Showers in production:

Based on 3D models, our in-house designers developed working drawings for the project, illustrating such things as armature design and specific dimensions

Many hours were put into finishing the positive forms by hand

Fibreglass moulds were created from the positive forms. Wooden supports were built for the moulds.

Testing at Scale:

We recommend a scale test sample for virtually every project we build. Test samples and mock-ups act as quality control samples for finished pieces and serve to ensure all parties have a complete knowledge of the process and can visualize the final result prior to full-scale production.

In our shop, Heavy poured a 1:1 scale test section of the Light Showers structures. The test pour gave Jill Anholt an opportunity to select the proper pigmentation and surface texture for her project. Additionally, the test pour allowed us to analyze the draft angles of the moulds, the specific mix of concrete, and the appropriate mould release to be used to ensure the moulds would function as intended and the pulls would meet Jill’s exacting standards for her artwork. The 1:1 test section turned out very well. This test section was viewed by all key stakeholders and would later be used as a quality control sample for the finished pieces.

Here are some photos from the production of the test piece:

Heavy’s mould of the wavy textured concrete pavers, also part of the project

CNC cut templates were laid into the mould, attached, and sealed.

The test pieces were poured

The test pour was successful. You can see we used differently pigmented concrete to allow Jill Anholt to select her preference.

Unforeseen Challenges:

Heavy first got involved in the Light Showers projects after much of the process to execute the idea had already been planned. At this stage, another firm had already been contracted to pour the concrete and erect the massive sculptures. Working with various stakeholders, however, is common in our world. So, Heavy provided all the information for the concrete mix, release agent, and the process that worked very well during our test pour. Once we shipped the moulds to Toronto and communicated key pieces of information, our scope of work was intended to be complete until Heavy personnel returned to install the stainless steel strips near the end of the project. However, in the world of custom work, unexpected circumstances usually arise – the maturity of the fabricator is exposed in how they handle such unexpected events.

The main Light Showers elements are massive reinforced pre-cast concrete pieces that were poured flat on site before being erected. The concrete contractor on site began running into problems pouring the Light Showers elements. Large “burn” marks began appearing on the concrete and the concrete pieces were not releasing from the moulds as planned. After seeing the success of Heavy’s 1:1 test section in our shop, we were puzzled by the challenges that the concrete contractor was encountering on site. In an effort to see this project through to a successful completion, Heavy personnel travelled to Toronto to assist in finding a solution.

Heavy’s experienced moulding and concrete technicians started by creating new rubber inlays between sections of the moulds with sharper draft angles to assist with de-moulding. The rubber inlays could also be removed separately from the mould to further improve the ease of de-moulding. Our technicians gave the moulds a thorough cleaning and repaired some minor damage to the moulds from earlier pour attempts. Heavy made some further recommendations regarding the concrete mix and release agents used with consideration for the exterior Toronto climate where these massive forms were being poured. After some adjustments, the concrete elements finally began releasing properly from the moulds.

This effort shows off who we are as a company. We’ll never walk away from a situation until all the issues are resolved. When we put as much effort and care into a project as we do, we want to do everything we can to ensure the work is accurately executed in line with the original vision.

Here are some photos of our team working to clean and repair the moulds on site:

We cast large rubber strips with sharper draft angles and laid them in the moulds between sections to improve how the reveals would release

The moulds needed a fair amount of refinishing to restore their intended surface texture.

Here are some photos of the final structures being poured and erected by the other contractor on site:

The moulds being assembled

Reinforcing bar was laid into the moulds

Concrete curing; a special self-consolidating concrete mix was used

One of the structures being erected

One of the structures being lowered onto its foundation

One of the structures in place, prior to the moulds being removed

Here are a few photos of the unfinished structures while the site was still under construction:

Learning #1: Artistic concrete takes time. The production of artistic and architectural concrete pieces requires a high level of care and experience to achieve the standard of quality most of our clients expect. Tricks of the trade to speed things up when pouring curbs and sidewalks simply cannot be used to build an interactive art piece.

Learning #2: Communication is everything. When multiple stakeholders are involved in a project, no matter the size, open lines of communication and frequent progress checks are vital to that project’s success. The key to a dilemma could lie within easy reach if the right people are asked. Furthermore, issues can be prevented from escalating with consistent discussion throughout a project and utilization of everyone’s expertise. This theory holds true for every business, though one particularly important for custom fabrication. Heavy’s project management team continues to grow in both size and experience, with the addition of two new senior project managers this year, to further improve our communication and coordination with project stakeholders to pre-emptively avoid problems.

Learning #3: Choose the best materials. When Heavy got involved in this project, solid, site-cast concrete was already decided on for the material to produce the massive sculptural elements. However, if Heavy were to take on a similar project again, we would propose using thin panels of glass fibre reinforced concrete (GFRC) instead of the solid, site-cast concrete. There are several benefits GFRC panels would present for such large scale, complex curved forms as the elements of Light Showers. First of all, due to its high tensile and flexural strength, GFRC sculptures can be cast in thin panelled sections with even greater impact resistance and durability than traditional pre-cast. These panels would then be attached to an internal framework.

Casting pieces in thin panels means the weight of the structure would be significantly reduced. The benefit of such a weight reduction means two things: First, the foundations and inner armature for the structures could be much smaller, reducing material and labour costs for those aspects of the project. Second, the panels could be cast in a humidity and temperature controlled shop for consistently controlled finish quality. The panels, being relatively light weight, could then be transported to site, easily attached, and only aesthetic seaming would be required out in the uncontrollable weather.

Learning #4: Build relationships with other subcontractors on site. Whether they’re involved directly with our project, or working on another aspect of the bigger picture, Heavy often works side-by-side on site with a mix of subcontractors. The most success in working together is usually found when a formal subcontractor relationship exists and efforts have been made to keep open lines of communication, share resources as is reasonable, and generally cooperate in a mutually beneficial manner among everyone one site. When everything is set up properly prior to anyone arriving on site, there is a simple way to resolve conflicts and both parties are motivated to fix any issues in an economical and expeditious manner.

The Result
When Heavy returned to Toronto one last time to install the stainless steel strips, it was clear that working with all the stakeholders to find a solution was worth the finished result. Heavy installed the stainless steel insets onto the finished concrete structure by precisely fitting each inset to the curvature of the sculptures by hand. Finally, the water circulation systems were integrated and the sculptures were completed with art glass panels and custom lighting.

In this photo, the insets that hold the stainless steel strips are clearly visible.

All of the steel strips were pre-cut with standoffs welded in place

All the stainless steel strips were installed, bending each strip by hand to the curvature of the sculptures.

The strips were held in place while the adhesive cured

Here are some photos of the completed Light Showers project to give you a sense of the artwork during both the day and night and how much people enjoy meandering around the park: