Masonry Tie Bar Calculator
Tie bar count, weight, holes and resin from wall and spacing.
Inputs
Result
Formula
| Courses | n = floor(height ÷ spacing), at least 2 |
| Total bars | N = courses × bars per course |
| Total length | L = N × length into wall |
| Weight | W = L × 0.00617 × d² |
| Resin | V = N × resin per hole |
A 3 m wall at 500 mm spacing with 2 Φ6 bars per course extending 1000 mm: 6 courses, 12 bars, 12 m total, 2.66 kg, 12 holes and about 180 ml of resin.
FAQ
Must tie bars be resin-anchored?
Depends on the structure. Columns can be cast-in or drilled-in, shear walls usually have starter bars or resin anchors, and infill-to-tie-column joints are normally cast in. Cast-in is most reliable but easily misplaced; resin anchoring is flexible but needs drilling, cleaning, injection, curing and pull-out tests. Bars missed during the frame stage are the commonest source of rework.
Why at least two courses per storey?
With only one tie the infill can rotate about it like a door, cracking and spalling away from the beam soffit. Two or more courses restrain the panel in the frame plane. Seismic areas also require continuous bars tied into the tie columns to make the panel act as a unit.
How is pull-out testing done?
Sample at least three bars per inspection lot, load to 1.2 times the design value, hold two minutes, and pass if there is no slip or cracking. A failure means doubling the sample; a second failure invalidates the lot, requiring extra bars or a different connection. Keep the records — they are checked at handover.
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Results are estimating aids only and are not a design basis. Construction and final accounts must follow the drawings, the applicable standards and an approved method statement. Anything affecting structural safety, shoring or falsework must be checked by a suitably qualified engineer.