3 minute read
Decking Material Review
Perkins&Will
No. 03 – 030621 June 3, 2021
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All parties copied in this report, please notify the author within three working days should any discrepancies be noted.
cc: Kirk Robinson, DELTA Deanna Yue, DELTA James Higgins, RDH Mona Lemoine, PW Aik Ablimit, PW Elton Gjata, PW Tom Burvold, Urban One Ricardo Dupouy, Urban One Miguel Zapiola, Urban One Brent Olund, Urban One
Sensor Plan Markup
Decking Material Review
Matthew Wollin Sales & Specifications Representative Upper Canada Forest Products 604 374 5435 mwollin@ucfp.com
Decking Material Review Canada Earth Tower – Mock-up Assembly June 08, 2021
Upper Canada Forest Products (UCFP) is grateful to be a participant in the Canada Earth Tower, Deck Assembly mock-up. For this mockup, two separate deck materials have been installed. 1. Accoya – Acetylated Radiata Pine 2. Thermal Ash – ThermalWood Canada’s heat-treated ash
Deck Board
Sub Assembly Dimensions 20mm x 140mm 26mm x 145mm Clip Height Flush Total 46 mm
Future Considerations
1. Expansion and contraction of thermal ash decking system 2. Substructure ventilation and screw penetration 3. Natural “Greying” and coating systems 4. Deck board orientation
Based on technical data from the Accsys Group, Thermal Ash will experience additional expansion and contraction. Over time this will result in a less even decking surface. Review of butt joints should be completed during the testing window. Please reference chart below (both installed decks are tangential sawn). Thermal Expansion:
Substructure Ventilation and Screw Penetration
Accoya recommends that a minimum of 25mm of fastener penetration be obtained for deck installations. If Accoya is used as a subframe, they suggest a minimum of 10mm between the end of the fastener and the bottom of the sub assembly board. This creates a 35mm minimum total sub assembly height from a fastening perspective. Screw Penetration:
For typical deck applications Accoya’s technical literature recommends a 70mm ventilation space. There may be an argument that the deck system’s exposure to wind/air flow should allow for better ventilation in comparison to a traditional ground level deck. The mock-up testing should provide helpful data regarding moisture build up. Check for mold or mildew growth at the edges of the decking material.
Ventilation:
Natural “Greying” and Coating Systems
The Accoya deck was left 100% raw. Thermal Ash has a CUTEK oil-based coating that was used to help prevent surface checking. In both cases the material will naturally grey due to UV exposure. If desired, a coating system can be applied to both products to help maintain colour and prevent greying. Further information on coating systems can be found in Accoya’s technical literature. Accoya Greying timeline: Thermal Ash Greying Example:
Thermal Ash Greying Example:
http://thermallymodifiedwood.com/blog/the-natural-graying-effects-of-thermally-modified-wood-does-it-effect-its-durability/
Deck Orientation
On the parallel deck design considerations should be made to ensure the secure fastening of the shortest angled deck board. In this orientation an additional sub-frame support may be required. Thermal Ash Parallel Deck:
June 2, 2020 – Mock-Up Photo
Final Comments
• Additional Accoya resources have been attached in the accompanying email. • For additional information on Thermal Ash questions can be addressed by Thermalwood Canada product experts. Please reach out to Matthew Wollin – mwollin@ucfp.com - as questions arise and UCFP can facilitate further product investigations. • Final design and substructure should be reviewed by a deck installation expert.
