Base Track 93 mm × 2.5 m — Aluminium Starter Profile for 90 mm Solid-Wall Insulation

Product Overview

The Base Track 93 mm × 2.5 m is an aluminium starter profile sized to accept 90 mm insulation boards — the thickness most commonly specified for solid-wall properties where energy assessors identify a need to step beyond the standard 80 mm build-up to approach tighter U-value targets. Positioned directly above the damp-proof course, this track provides a rigid, level shelf that anchors the first course of insulation and establishes the base line for the entire EWI system around the building perimeter. Each 2.5 m length is pressed from corrosion-resistant aluminium alloy at a standard 0.6 mm gauge, offering lightweight handling and clean cutting on site. The integral drip edge on the lower lip directs rainwater clear of the insulation face, and perforations along the horizontal shelf ventilate residual moisture from behind the boards. This profile ships without pre-installed mesh — a clip-on mesh carrier snaps onto the front edge for integration into the basecoat reinforcement layer. It is available within the insulation fixing accessories range at Renders World.

Key Benefits

• Targeted at solid-wall insulation specifications — the 93 mm channel is precision-sized for 90 mm EPS graphite boards, the thickness most frequently calculated for 9-inch solid brick walls where the extra 10 mm over the standard 80 mm build-up closes the gap toward a 0.30 W/m²K wall U-value, subject to calculation.
• Standard 0.6 mm gauge aluminium — this is the standard-gauge version of the 93 mm profile, suitable for domestic and low-rise commercial projects; a separate 1 mm heavy-duty 93 mm base track is available where greater rigidity or higher load capacity is specified.
• Integral drip edge — the formed lower lip projects beyond the wall face, shedding rainwater and splash-back away from the insulation system at the base zone where moisture exposure is highest.
• Perforated web for base-zone ventilation — punched apertures along the horizontal shelf allow trapped construction moisture and minor vapour drive to escape, supporting long-term drying performance behind the insulation.
• Corrosion-resistant construction — the natural aluminium oxide layer resists alkaline basecoat chemistry, prolonged moisture contact, and atmospheric degradation throughout the service life of the EWI system.
• Fast installation and accurate alignment — each 2.5 m length is light enough for single-person handling, cuts cleanly with tin snips, and fixes at 300 mm centres with standard masonry anchors to establish a true horizontal datum line.

Technical Specifications

Property	Value
Profile width	93 mm
Length	2,500 mm (2.5 m)
Material	Aluminium alloy
Gauge (thickness)	0.6 mm (standard)
Finish	Natural aluminium (mill finish)
Drip edge	Yes — integral lower lip
Perforated web	Yes — ventilation apertures
Pre-installed mesh	No — clip-on profile required
Recommended fixing centres	300 mm
Suitable insulation thickness	90 mm boards
Corrosion resistance	Inherent aluminium oxide layer

Application and Compatibility

The 93 mm base track is specified primarily on solid-wall properties — pre-1930 terraces, Victorian and Edwardian houses, and inter-war homes built with 9-inch solid brickwork. On these substrates a 90 mm graphite EPS board with a lambda of 0.032 W/mK typically brings the wall U-value into the region of 0.27–0.32 W/m²K, subject to the existing wall construction and calculation method. That additional 10 mm over the widely used 80 mm build-up can be the difference between meeting and narrowly missing the target set by the energy assessor, particularly on exposed elevations or properties with thinner-than-expected brickwork.

This profile pairs directly with 90 mm graphite EPS boards from the EPS insulation boards collection. For mixed-thickness projects, the 83 mm base track handles elevations where 80 mm insulation satisfies the calculation, while the 103 mm base track accommodates 100 mm boards on properties that require a further thermal step-up — typically semi-detached gable ends or north-facing walls with higher heat-loss rates.

Installation Notes

For the best result, establish the datum line around the full building perimeter before fixing any track. Use a laser level or water level, transferring the reference to each elevation and snapping a chalk mark as a permanent guide. The track typically sits 150 mm above finished ground level and directly above the DPC. Pre-drill at 300 mm centres using a 6 mm masonry bit, then fix through into the substrate with wall plugs and screws rated for the masonry type.

Solid brick walls generally provide excellent pull-out resistance for standard nylon frame plugs. On older brickwork with soft lime mortar joints, position fixings within the brick faces rather than the joints to ensure consistent anchorage along the full track run. Leave a 2–3 mm expansion gap between adjacent track lengths. At external corners, mitre-cut both lengths at 45° to maintain continuous drip-edge protection. At internal corners, butt one length into the adjacent wall face and seal the junction with compatible sealant.

Once the track is fixed and verified level, apply adhesive to the rear face of each 90 mm board and seat it firmly onto the horizontal shelf. After the first course is set, attach the clip-on mesh profile to the front lip and embed the mesh into the basecoat layer. Full step-by-step procedures, including adhesive application patterns and mechanical fixing placement above the track line, are covered in the insulation fixings installation guide.

Installer's Note

The 93 mm track comes into play on every solid-wall job where the energy assessment pushes past 80 mm. On Victorian terraces especially, the original brickwork can vary in thickness from one elevation to another — a 215 mm party-wall return next to a 325 mm front wall is not unusual — and the energy assessor may specify 90 mm on the thinner sections while 80 mm satisfies the rest. Carrying both the 83 mm and 93 mm profiles on site allows both specifications to be installed from the same datum height without compromising the level line. Where both tracks meet at a change in insulation thickness, align the rear face of the track against the wall so the front lip steps forward by 10 mm. The basecoat and mesh layer bridges that step cleanly provided it is formed in a single wet pass rather than feathered back after curing.

Is This Product Right for Your Project?

• Ideal for solid-wall retrofit projects — choose the 93 mm base track when the energy assessment specifies 90 mm EPS insulation boards on 9-inch solid brickwork, Victorian terraces, or Edwardian properties where the extra thickness targets a U-value approaching 0.30 W/m²K, subject to calculation.
• For standard domestic retrofits on 80 mm boards — the 83 mm aluminium base track is the profile matched to the UK's most popular insulation thickness, suitable for the majority of cavity-wall over-cladding and general masonry retrofit projects.
• For deeper retrofits requiring 100 mm insulation — the 103 mm base track accommodates the next standard board thickness, specified on semi-detached gable ends, north-facing walls, and properties targeting enhanced thermal performance.
• When a heavy-duty profile is required at 93 mm — the 1 mm gauge heavy-duty 93 mm base track offers greater rigidity for exposed sites, multi-storey facades, or specifications that call for a thicker-gauge aluminium profile at this width.

Frequently Asked Questions

When would an energy assessor specify 90 mm instead of 80 mm?

The step from 80 mm to 90 mm is most often triggered by the existing wall construction. A solid 9-inch brick wall has a higher baseline U-value than a cavity wall of similar age, so it requires thicker insulation to reach the same target. Where the assessor's calculation shows that 80 mm graphite EPS falls just short of the required U-value — typically on exposed elevations or properties with below-average brickwork thermal resistance — adding 10 mm brings the result within the target range without the detailing complexity that comes with a jump to 100 mm or above.

What is the difference between this track and the 1 mm heavy-duty 93 mm version?

Both profiles share the same 93 mm channel width and 2.5 m length, accepting identical 90 mm insulation boards. The difference is the aluminium gauge: this standard track uses 0.6 mm material, which is appropriate for domestic and low-rise projects. The 1 mm heavy-duty version provides greater rigidity and higher load capacity, specified on multi-storey facades, highly exposed sites, or when the EWI system designer requires a thicker-gauge starter profile as part of the system certification.

How many tracks do I need for a Victorian mid-terrace?

A typical Victorian mid-terrace has insulation applied to the front and rear elevations only, with party walls shared with neighbouring properties. Measure the combined linear run of front and rear base lines — commonly 10–14 m in total — and divide by 2.5. Five to six lengths typically cover a mid-terrace with trimming allowance, plus one spare length for mitre waste at any external corners or bay-window returns.

Does the 90 mm insulation thickness affect window-sill extensions?

Yes — thicker insulation increases the total wall build-up, which means existing window sills may no longer project far enough beyond the new facade line. On a 90 mm EPS build-up plus basecoat and render finish, the total added depth is approximately 100–105 mm. Window-sill extensions or over-sills are typically required to maintain a drip edge beyond the new render face. The specific extension depth depends on the original sill projection and the finished render thickness.