ZONT™ BRACING - Ideal for multi-height ICF walls

This project, located on the granite cliffs near Deep Cove, North Vancouver, BC, has a spectacular view overlooking the waters of Indian Arm. The general contractor is the Econ Group with excavation by Headwater Management.

View from the top of site to the waterfront, with 2 excavators operating in tandem.

• This 3-D model of the site was produced from surveyor and Econ reference points.
• The 3-D model was used to estimate the quantity of Amvic® blocks.
• The lower backhoe is excavating for the first level of footings.
• Two backhoes operating in tandem were required to remove the overburden from the steep site.
• This backhoe is moving the overburden from the lower levels to the backhoe above.
• Mike Dutson, principal, Econ Group, stands on the construction access roadway located midway on the site.
• The only way to move on the site was by using the site built staircase (looking to the top of site).
• The Architect's east elevation, the red line shows the rock profile.
• The Architect's west elevation, the red line shows the rock profile.
• The Architect's north elevation overlooking the ocean.

Challenging Site

The building site has an elevation change of 177' from the waterfront at the north end to the public roadway at the south. A construction road (four wheel drive accessible) runs from the public road at the top to a construction staging area at the 125' elevation. The staging area was used to store construction materials, locate the site office and line pump for filling the forms.

The foundation is located near the waterfront and runs up the granite face resulting in footing elevation changes of over 28'. Footings were formed with Fastfoot® and had 17 different levels to accomodate the rocky terrain. Substantial blasting and rock removal was required to obtain level areas for the footings.

View from the waterfront, the house in the top left corner is the top of the lot 177' above.

• View from the north west, the lower level of the house will have direct ocean access.
• Looking south at the top of the first level foundation walls.
• These walls are 17' in height, note the extensive steel in the walls.
• View from the third level looking down at the second level.
• View at the top of the foundation (south end), note the rugged rock conditions.
• Zont™ brackets were perfect for truing up the walls both horizontally and vertically.
• The slot in the vertical face of the Zont™ allows for vertical compression of the ICF.
• Scaffolding was made with site lumber which will be used for framing in the house.
• End-of-wall end bucks are easily braced. This is not possible with ICF bracing.
• There are 10 end-of-wall bucks in the foundation, all braced between the walers.

Foundation Walls

Foundation walls were built with Amvic® insulating concrete forms. This block was chosen for two reasons: first, the 6" spacing on the ties provided greater strength. Second, the foundation had many interior walls requiring T-junctions manufactured by Amvic®.

"We chose Zont™ Bracing because of  the many different wall heights", said Carey Brown, Site Manager. "Some walls were 4' high, others were 17'. As the walls got taller, we installed another level of Zonts™ and walers."

"As well, Zonts™ make it easy to support end-of-wall bucks between the horizontal walers. We couldn't do this with ICF bracing."

Front end loader delivers concrete from the ready mix truck above to the line pump at mid-station.

• The loader moves concrete from the ready mix truck above to the line pump below.
• Footings over the jagged granite were formed with Fastfoot®.
• On the steep drop-off to the right, the ICF blocks were scribed to the rock.
• Vancouver is a high seismic area, rebar requirements were significant.
• The contractor has placed a Zont/waler assembly on the top of this wall to align it precisely.
• Ready for concrete.
• The line pump travels down the staircase to the top of foundation.
• Filling the forms, the ICF block and bracing performed perfectly.
• Filling the forms was uneventful.
• Zonts™ allow for vertical compression due to heat buildup during the concrete pour.

Pouring Concrete

Concrete delivery was a challenge:

• Ready mix trucks delivered the concrete to the end of a small public roadway;
• A front end loader with a concrete hopper delivered concrete to a line pump located at mid-station;
• 200' of 4" line travelled down the site built staircase to the top of foundation walls.

"Pouring the foundation walls was uneventful except for a breakdown in the line pump", said Carey.

"Zonts™ did a great job in flattening our walls."