Wall Tie Repairs

How to establish wall thickness and cavity width

Caliper Method

Measure the overall thickness of the wall near a door opening or window reveal. this is easiest done using a caliper then measuring the width of the open point in the caliper jaws, take of 30mm from the overall width of the wall and you have your appropriate tie length.

Pilot drill method

Use a 6mm x 260mm drill bit, from the outside of the wall drill to approximately 110mm depth, you should feel the drill bit pressure drop as it breaks into the cavity. Mark or pinch the drill bit at its abutment with the wall, extract the drill bit, measure the distance, this will give you the thickness of the outer leaf material.

Reinsert the drill bit and push it into the wall till you hit resistance. Pinch or mark the drill bit at its abutment with the wall, then extract,

The thickness of the outer leaf measurement taken first, subtracted from the second measurement gives you the thickness of the cavity.

Both of these processes are very simple and quick to complete and give confidence as to which tie length to use.

Note: it is really not uncommon for cavity width to vary, due to poor construction techniques, on large jobs with multiple walls it is best to check a few walls to be safe.

HOW TO VIDEO

Cavity Wall Ties

Retrofitting cavity wall ties using Strucsol Locties

Wall tie length

Tie length Cavity Suitability Wall thickness minimum
195mm 5mm-45mm 210mm
210mm 10mm-60mm 240mm
220mm 15mm 70mm 250mm
240mm 50mm-90mm 270mm
270mm 100mm-120mm 300mm

Minimum embedment in inner leaf 70mm unless tensile proof tested.

What size Pilot hole do I need to drill?

People who tell you one size of pilot hole will do the job are not being thorough. Using a standardised pilot hole can lead to underperforming ties or difficulty in installing ties.

Harder materials need larger pilot drills, softer materials need smaller diameter pilot holes.

For example:

  • Drilling through a blue engineering brick might need a 7mm pilot hole for an 8mm diameter tie
  • Fixing into AAC or lightweight block requires no pilot hole, so a pilot drill is only required in the outer leaf.
  • Soft to medium hardness brick inner and outer leaf will probably need a 6mm or 6.5 mm diameter pilot drill in both leaves of the wall.
Wall tie pull out strength

The amount of force required to pull a wall tie out of the wall is relevant as the installed ties are there to prevent failure of the wall due to wind suction loads.

Wind suction loads vary depending on where you are in the county. Coastal and Northern areas have higher wind loads than sheltered inland areas, which leads to higher capacity requirements from the ties, or increased density of ties.

Taller buildings are more exposed to high winds and need even more resistance to wind suction.

The Strucsol Engineering team has been designing cavity wall ties specifications for everything from Sky scrapers to cottages for more than 30 years- we provide advice and consultations for free for one off customers of trade contractors and specifiers. Just get in touch with us either by phone or email and we'll be more than happy to help.

Detailed Wall Tie Method Statements

SMA07 Masonry arch pinning of debonded bricks using Mechanical Remedial Wall Ties
SMA08 Reconnecting near leaf brick to hollow blocks using Mechanical Remedial Wall Ties
SMA09 How to reconnect near leaf brick to natural materials (cob, wychert etc) using Remedial Wall Ties
SMS01 Creating a structural beam in solid walls using StrucSol reinforcing bar
SRS01 Repair of dilapidated or separating masonry in a rubble filled or solid wall using Grout Ties
SRS02 Repair of brick-faced random stone walls using Grout Ties through brick faces
SRS03 Hidden repair of brick-faced random stone walls using Grout Ties through mortar joints
SRS04 Repair of stone-faced random stone walls using Grout Ties through stone faces
SRS05 Hidden repair of stone-faced random stone walls using Grout Ties through mortar joints
SRS06 Repair of brick quoins on random stone walls using Grout Ties
SRS07 Repair of brick quoins on random stone walls using Grout Ties and StrucSol Ultrabar
SRS08 Repair of stone quoins on random stone walls using grout ties
SRS09 Repair of stone quoins on random stone walls using Grout Ties and Helical Bar
SWM01 How to reconnect a cracked internal wall to an external cavity wall using helical bar
SWM02 Reconnecting a cracked internal wall to an external cavity wall using grout ties
SWM03 Reconnect a cracked internal wall to an external solid wall using StrucSol Ultrabar
SWM04 Reconnecting a cracked party wall to an external solid wall using Grout Ties
SWM05 How to reconnect a cracked internal / party wall to an external stone wall using Grout Ties
SWM06 Reconnecting near leaf masonry to far leaf bricks or blocks using Mechanical Remedial Wall Ties
SWM07 Reconnect near leaf masonry to far leaf bricks or blocks using mechanical / resin wall ties
SWM08 How to reconnecting near leaf brick to hollow blocks using Mechanical Remedial Wall Ties
SWM09 Reconnecting near leaf brick to solid concrete using Mechanical Remedial Wall Ties
SWM10 Reconnect near leaf brick to solid brick using mechanical / resin wall ties
SWM11 How to reconnect near leaf brick to timber stud using Mechanical Remedial Wall Ties
SWM12 Reconnecting near leaf brick to timber stud using Mechanical / Resin Wall Ties
SWM13 Reconnecting limestone / sandstone / travertine / granite / marble to concrete using Mechanical Remedial Wall Ties
SWM14 Reconnect limestone / sandstone / travertine / granite / marble to multi-leaf brick / solid masonry using Mechanical Remedial Wall Ties
SWM15 How to pin multi-leaf brick / solid masonry using Mechanical Remedial Wall Ties (angled entry)
SWM16 Pinning multi-leaf brick / solid masonry using Mechanical Remedial Wall Ties (horizontal entry)
SWM17 How to reconnect terracotta to concrete using Mechanical Remedial Wall Ties
SWM18 Reconnecting terracotta to multi-leaf brick / solid masonry using Mechanical Remedial Wall Ties
SWM19 Reconnecting near leaf brick to steel stud using Mechanical Remedial Wall Ties
SWM20 Reconnecting steel stud to outer leaf brick using Mechanical Remedial Wall Ties (internal application)
SWM21 Reconnecting near leaf brick to aircrete / aerated concrete using Mechanical Remedial Wall Ties
SWM22 Reconnecting near leaf brick to aircrete / aerated concrete using mechanical / resin wall ties
SWM23 Reconnecting near leaf brick to natural materials (cob, wychert etc.) using mechanical remedial ties
SWM24 Reconnecting render / stucco to solid concrete using Mechanical Remedial Wall Tie render pin
SWM25 Reconnecting near leaf brick to no-fines concrete panels using Mechanical Remedial Wall Ties
SWM26 Reconnecting near leaf brick to no-fines concrete panels using mechanical / resin wall tie
SWM27 Reconnecting near leaf brick to clay tile / hollow clay block using Mechanical Remedial Wall Ties
SWM28 Reconnecting near leaf brick to far leaf brick or block using mechanical / resin wall tie
SWM29 Reconnecting limestone / sandstone / travertine / granite / marble to solid concrete using asymmetric Mechanical Remedial Wall Tie
SWM30 Reconnecting limestone / sandstone / travertine / granite / marble to solid concrete using asymmetric Mechanical Remedial Wall Ties
SWM31 Reconnecting near leaf masonry to far leaf bricks or blocks using grouted mechanical / resin wall ties