Description
The 93 mm base track is the aluminium starter profile sized for 90 mm insulation boards, the thickness an energy assessor most often calls out when a solid brick wall needs to step beyond a standard 80 mm build-up. It fixes above the DPC and sets the level datum that every course of insulation above it inherits.
Where the 93 mm Base Track Performs Best — UK Applications
At 93 mm channel width and 2.5 m per length, this aluminium starter track carries 90 mm graphite EPS on solid-wall retrofits, fixed above the DPC at 300 mm centres to set the perimeter datum. It belongs to the wider insulation fixing accessories range, where every base track width is matched to a board thickness held elsewhere in the silo. Get the track level and the whole elevation lines up behind it.
The 93 mm width answers a specific UK situation: the 9-inch solid brick wall that an assessment pushes past 80 mm. Where cavity-wall properties are usually served by the standard 83 mm profile, Victorian and Edwardian solid-brick facades frequently land on 90 mm to reach a wall U-value in the region of 0.30 W/m²K, subject to calculation. Renders World holds this profile in stock precisely because the 90 mm specification recurs so often on period-property retrofits.
Why Trade Specifiers Choose the 93 mm Base Track
- Matched to the 90 mm solid-wall spec — the 93 mm internal channel seats 90 mm graphite EPS boards cleanly, so no packing or improvised shims enter the base course on 9-inch solid brick.
- Integral drip edge — the formed lower lip projects clear of the wall face, shedding rainwater and splash-back away from the base zone where moisture exposure concentrates.
- Perforated horizontal web — punched apertures let residual construction moisture escape behind the insulation, supporting the drying performance of the finished system over its service life.
- 0.6 mm aluminium gauge — light enough for single-person handling, cuts cleanly with tin snips, and resists alkaline basecoat chemistry through the natural aluminium oxide layer.
- Accurate datum line — fixed at 300 mm centres, each 2.5 m length lays true and gives the first board course a level seat that carries through to the render finish.
Technical Specifications — 93 mm Base Track Data
| Property | Value |
|---|---|
| Profile width | 93 mm |
| Length per piece | 2,500 mm (2.5 m) |
| Material | Aluminium alloy |
| Gauge | 0.6 mm (standard) |
| Finish | Natural mill aluminium |
| Drip edge | Integral lower lip |
| Ventilation | Perforated horizontal web |
| Recommended fixing centres | 300 mm |
| Suitable insulation thickness | 90 mm boards |
| Pre-installed mesh | No — clip-on profile required |
How the 93 mm Base Track Installs Above the DPC
For the best result, establish the datum line around the full building perimeter before any track is fixed. A rotary laser transferred to each elevation, with a chalk reference snapped along the run, keeps the line continuous around corners and returns. The track typically sits about 150 mm above finished ground level and directly above the existing DPC.
Pre-drill at 300 mm centres with a 6 mm masonry bit, then fix through into sound substrate with nylon frame plugs and screws rated for the brickwork being anchored. On older solid walls with soft lime mortar, place fixings within the brick faces rather than the joints to keep pull-out resistance consistent along the full run.
- External corners — mitre-cut both lengths at 45° so the drip edge stays continuous around the return.
- Internal corners — butt one length cleanly into the adjacent wall face and seal the junction with a compatible flexible sealant.
- Expansion gaps — leave 2–3 mm between adjacent lengths so the aluminium moves freely under thermal load without bowing.
- Thickness changes — where the 93 mm profile meets an adjoining 83 mm or 103 mm track, align the rear faces to the wall and bridge the step in a single wet pass of basecoat and mesh.
Once the track is verified level, adhesive-bond each 90 mm board onto the horizontal shelf and clip the mesh profile to the front lip ahead of the basecoat layer. Full fixing patterns, anchor placement above the track line, and adhesive coverage rates are covered in the step-by-step EWI fixings installation guide.
Pro Tips From UK Installers Fitting the 93 mm Base Track
The 93 mm track comes into play on solid-wall jobs where the assessment pushes past 80 mm. A few site habits separate a clean perimeter from one reworked once the boards go up.
- Carry the neighbouring profile on site — Victorian terraces vary in wall thickness between elevations, and an assessor may call 80 mm on party returns while specifying 90 mm on front and rear. Keeping the 83 mm track on the van means both come off one datum.
- Lay a dry run before drilling — set every length end-to-end along the chalk line, mark the fix positions through, then pull back to drill. It catches fix points that fall on movement joints or service penetrations before the bit goes in.
- Level with a laser, not a spirit level — a rotary laser keeps the DPC line true across returns and bay windows, and the whole board stack above inherits that accuracy.
- Step up where the assessor calls for 100 mm — exposed gable ends and north-facing walls may need thicker insulation than the front elevation, and the 103 mm track accommodates that step without disturbing the perimeter datum.
How the 93 mm Base Track Compares to Sibling Base Tracks
The base track family steps up in fixed increments to match standard UK board thicknesses. The three central profiles in the range cover the bulk of domestic retrofit work — pick the one that matches the insulation depth on your energy assessment.
| Variant | Key Spec | When to Choose |
|---|---|---|
| 83 mm base track | 80 mm boards · 0.6 mm | Standard cavity-wall domestic retrofit |
| 93 mm base track | 90 mm boards · 0.6 mm | 9-inch solid brick, Victorian terraces |
| 103 mm base track | 100 mm boards · 0.6 mm | Semi gable ends, north-facing walls |
Where a taller or more exposed facade calls for greater rigidity at the same width, the 1 mm heavy-duty 93 mm track accepts identical 90 mm boards in a thicker aluminium gauge.
Is the 93 mm Base Track Right for Your Project?
- Ideal for 90 mm solid-wall retrofits — choose it when the energy assessment specifies 90 mm graphite EPS on 9-inch solid brick, Victorian terraces, or Edwardian properties targeting a wall U-value near 0.30 W/m²K, subject to calculation.
- For standard 80 mm domestic work — the 83 mm profile matched to 80 mm boards suits the majority of cavity-wall over-cladding and general masonry retrofit.
- For deeper 100 mm retrofits — the 103 mm profile for 100 mm boards covers semi-detached gable ends and enhanced-performance specifications.
- Pair with matched boards — order alongside 90 mm boards from the graphite EPS insulation boards collection, or compare against slab systems in the Rockwool mineral wool range where the fire strategy calls for it.
FAQ — 93 mm Base Track Coverage, Compatibility, Ordering
How many 93 mm tracks does a typical solid-wall retrofit need?
A Victorian mid-terrace usually carries insulation on front and rear elevations only, with party walls shared. The combined run is commonly 10–14 metres, so five to six 2.5 m lengths cover most mid-terraces with a trimming allowance plus one spare for mitre waste at external corners. Measure the full perimeter to be insulated and divide by 2.5.
What is the difference between the standard 93 mm track and the 1 mm heavy-duty version?
Both share the same 93 mm channel and 2.5 m length, and both accept identical 90 mm boards. The difference is gauge: this profile is pressed from 0.6 mm aluminium for domestic and low-rise work, while the 1 mm heavy-duty version adds rigidity for taller facades, exposed coastal sites, or where the system designer specifies a thicker starter profile as part of the certification.
Does 90 mm insulation affect existing window sills?
A 90 mm build-up plus basecoat and render adds roughly 100–105 mm to the wall depth, so existing sills often no longer project far enough beyond the new facade line. Over-sill extensions are usually required to keep a clean drip edge ahead of the finished render — the depth depends on the original sill projection, so measure on site before ordering.
What fixings work best when anchoring the 93 mm track to older brickwork?
Standard nylon frame plugs with 6 mm masonry screws perform well in sound Victorian and Edwardian brick. On soft lime mortar, place each fixing within the brick face rather than the joint for consistent pull-out. Where the substrate is friable, step up to a resin-bonded anchor at the affected points rather than reducing centres across the run. Anchor selection for the boards above the track is detailed in the fixing pattern and spacing method.
How well does the aluminium profile hold up over the service life of the system?
Aluminium forms a self-healing oxide layer that resists alkaline contact from cementitious adhesives and long-term moisture at the splash-back zone, so in normal UK conditions the profile performs for the full service life of the surrounding render. On highly exposed coastal sites, the 1 mm heavy-duty version adds reserve against pitting, though both gauges use corrosion-resistant alloy.
How should base tracks be stored on site before installation?
Lay or stand the lengths flat against a wall with no heavy materials on top, since a kinked profile cannot be levelled once installed. Kept dry and undamaged, aluminium base tracks have effectively indefinite shelf life and reach the trestle straight from Renders World stock ready to fix.