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MASA Bottom Plate Anchor

The MASA Bottom Plate Anchor provides a time‑saving alternative to M12 and M16 cast‑in‑place anchor bolts on 45mm bottom plates. Designed to install on the formwork before the pour, they simplify concrete finishing and can easily adapt to timer stud interference.

Designing with MASA mudsill anchors also eliminates the need for 75mm square plate washers on the anchor bolts for seismic design, and in some cases offers load capacities that meet or exceed the parallel‑ and perpendicular‑to‑plate shear capacity of other cast‑in‑place anchors.

Key Features
  • Attaches easily to the concrete formwork
  • Stays out of the way until needed, making slab finishing easier
  • Eliminates the need to pre‑drill bottom plates for anchor bolts
  • Adapts to timber stud placement with two installation scenarios
Scope of Use
  • An alternative to M12 and M16 cast‑in‑place anchor bolts on 45mm bottom plates
  • Design Capacities are available on the website 
  • Design Capacity is the lesser of (1) the Characteristic Capacity multiplied by the NZ Strength Reduction Factor (φ), and applicable the k modification factors following NZS 3603 and (2) the Serviceability Capacity which is the load at 3.2mm joint slip, which includes fastener slip and mudsill anchor deformation. Design Capacity is the minimum of test data and structural joint calculation
Limitations on Use


  • Use all specified fasteners 
  • Concrete shall have a minimum f’c = 17MPa
  • Spalling—Full loads apply for spalls up to a maximum height of 32mm and a maximum depth of 22mm. Any exposed portion of the mudsill anchor must be protected against possible corrosion
  • For prescriptive anchor spacing refer to table
  • Minimum MASA end distance is 100mm and minimum centre‑to‑centre spacing is 200mm for full load
  • For continuous load path, MASA should be installed on the same side of wall as uplift connectors
B1 Structure compliant
B2 Durability compliant
Independent Assessment
Independent Assessment
Test Results
Test Results
CAD Drawings
Technical Data Sheet
ICC-ES Evaluation Report


Product Approval


Research Report

RR 25851

Installation Guide
Full Catalogue: Timber Connectors NZS3604


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