Installation Guidance

Comprehensive installation procedures and best practices for all Thor Helical products.

Wall Tie Embedment Guide

Outer Substrate Embedment

Outer Material	Min Embedment (mm)	Max Embedment (mm)	Pilot Hole Ø (mm)
Brick / Block	90	99	6

Inner Substrate Embedment

Inner Material	Min (mm)	Max (mm)	Pilot Hole Ø (mm)
AAC	85	—	Not required
Dense Aggregate Concrete Block	65	80	6
Fletton Brick	65	80	6
Perforated Brick	65	80	5
Structural Concrete C30	40	50	7
Timber	35	—	—

Note: When drilling, do NOT use hammering-only setting on SDS drill — this can rupture the inside surface of the outer leaf, reducing tie embedment. Use percussion drill with masonry drill bit (rotary hammering).

Retrofit Cavity Wall Tie Installation

Drill Pilot Hole

Using percussion drill and masonry bit, drill through outer leaf into inner leaf. Pause in cavity to prevent drill whipping and hole misalignment.

Drive the Tie

Insert driving end into CDT-DRIVER SDS tool (pointed end leading). Drive into both leaves using lightweight hammer drill until fully embedded.

Patch & Conceal

Patch the pilot hole of the recessed tie with mortar to conceal the retrofit repair and restore the masonry finish.

Bed Joint Installation (Crack Stitching / Masonry Beams)

Route bed joint to 40mm depth, extending 500mm either side of crack

Clear debris, flush with water to ensure WHO-60 bonds to sound mortar

Pump WHO-60 grout bead to back of slot, ~10mm from exterior surface

Insert bars spaced equally: 1 bar=20mm / 2 bars=15,25mm / 3 bars=10,20,30mm

Trowel back displaced grout and re-point. Ensure full bar encasement in WHO-60.

Drill Bits for Masonry Pinning

For longer bars, progressive drilling should be used: drill incrementally increasing bit lengths to prevent 'whipping' of longer bits.

Thor Helical Drill Bit Range

Product Code	Drill Ø (mm)	Overall Length (mm)	Working Length (mm)
5.0,6.0,7.0 × 330	5, 6, 7	330	265
5.0,6.0,7.0 × 430	5, 6, 7	430	365
5.0,6.0,7.0 × 530	5, 6, 7	530	465
5.0,6.0,7.0 × 675	5, 6, 7	675	610
5.0,6.0,7.0 × 985	5, 6, 7	985	920
8.0 × 500	8	500	435
8.0 × 700	8	700	635
8.0 × 1000	8	1000	935
10.0 × 700	10	700	635
10.0 × 1000	10	1000	935
18.0 × 850	18	850	785
18.0 × 1310	18	1310	1245

SDS Adapter Tools

Thor Helical manufactures bespoke SDS adapter tools for rapid, repetitive installation of all helical ties and fixings.

CDT-DRIVER

Remedial Timber Frame Ties Ø5mm · Cavity Wall Ties Ø9mm · Masonry Pinning Ø9mm

CDT12-DRIVER

Masonry Pinning Ø12mm

TELETOOL (8/10/12)

Remedial Cavity Wall Tie Telescopic Setting Tool Ø8, Ø10, Ø12mm

AT5-SDS-TOOL

Timber Frame Wall Ties Ø5mm

AT7-SDS-TOOL

Thin Joint Wall Ties Ø7mm

M7-TS-SDS

Batten Frame Fixings Ø7mm

ISF-18A-SDS

Insulated Plasterboard Fixing Ø7mm

ISF-18A-DH

Insulated Plasterboard Fixing SDS Punch

ISF-35-SDS

Flat Roof Insulation Fixing Ø7mm · External Wall Insulation Fixing Ø7mm

Full Installation Guide

Download the complete installation guidance document

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