Head Restraints

Head restraints do the job ordinary wall ties can’t: they lock the uppermost course of masonry to the structural frame — whether that’s concrete, steel or timber — so wind suction, building sway or accidental impact can’t overturn the wall. Without positive restraint at the wall head, a blockwork panel relies solely on its own self-weight and slenderness ratio to resist lateral loads, and in many configurations that isn’t enough to satisfy PD 6697 or NHBC Standards.

Our range covers the full Ancon IHR, FHR and Vista VHR families — sliding restraints for frames that deflect, fixed restraints for rigid junctions, and dual systems that secure both leaves of a cavity wall in one operation. All stock is Grade 304 stainless (316 available), independently tested to BS EN 845-1, and ships free next working day on orders over £200 ex-VAT placed before noon.

Head Restraint Types: Which Do You Need?

The correct head restraint depends on two things: the type of structural frame above the wall, and whether vertical differential movement needs to be accommodated.

Ancon IHR — Internal Sliding Head Restraints

The Ancon IHR range is the most commonly specified head restraint in UK construction. The L-shaped channel stem is built into the top bed joint and perpend of the blockwork, and a sliding head section slots into the top of the channel and bolts to the underside of the slab or beam above. This sliding connection transfers lateral wind loads to the frame while allowing up to 50 mm of vertical movement (75 mm or 100 mm with extended heads) — accommodating frame deflection, slab shortening and thermal movement without cracking the masonry.

The IHR comes in four head variants to suit different fixing substrates:

IHR-B — drilled hole for M8 expansion bolt into concrete soffits. The Ancon IHR-B 225mm is our top-selling head restraint and delivers a 33.5x ROAS in PPC, making it the highest-performing product in this cluster.

IHR-S — hole for self-tapping screw into steel beams (including hollow sections from 4–12 mm thick). No site drilling required.

IHR-V — slotted hole for M8 bolt into concrete or steel, providing additional vertical adjustment at the fixing point.

IHR-C and IHR-H — specialist heads for cast-in channel (38/17 or 30/20) and hammer-on flange connections to structural steel without site drilling.

Ancon FHR — Fixed Head Restraints

Where no vertical differential movement exists between the frame and the wall — for example, masonry-to-masonry junctions or verified zero-deflection steel frames — the Ancon FHR provides a simpler, more economical solution. Two angles clamp the top block course and bolt directly to the soffit or beam. Each FHR delivers a design resistance of 1,890 N and is pre-drilled for both 100 mm and 140 mm blockwork.

Vista VHR — Head Restraints

Vista VHR head restraints offer a competitive alternative to the Ancon IHR for standard applications. The Vista range suits cavities from 75 mm to 125 mm and is available in configurations for 100 mm and 140 mm block, with the same Grade 304 stainless construction and BS EN 845-1 test compliance.

When Are Head Restraints Required?

PD 6697 and Eurocode 6 require positive lateral restraint at the top of any masonry panel that cannot be bonded over or is not otherwise restrained by the structure above. In practice, this means head restraints are needed wherever blockwork stops below a concrete slab, steel beam or roof structure, at the top of internal partition walls that extend to the underside of the floor above, at the inner leaf of cavity walls where the outer leaf is independently supported by shelf angles, and at parapets and upstands above roof level.

NHBC Standards Chapter 6.1 reinforces this requirement for residential construction: any masonry panel without positive top-edge restraint must be structurally justified by the designer, which often results in thicker blocks or additional bed-joint reinforcement that costs more than fitting restraints in the first place.

Selecting Head Restraints by Application

Not sure which head restraint suits your detail? Read our head restraint comparison guide for a full breakdown of IHR-B vs IHR-S vs IHR-V, or call 0118 922 7941 — we’ll match the plate while your brickies set out.

Related products: wall ties for mid-panel lateral restraint between leaves.