PRODUCT PREPARATION MIXING & WORKING TIME 

SUBSTRATE ASSESSMENT & PRIMING

• The façade must be load‑bearing, level, dry, and free from cracks, delaminations, biological growth, oils, salts or loose dust.
• Under no circumstances should uneven substrates be levelled using excessive layers of adhesive. Instead, boards of different thicknesses should be selected to ensure a uniform final surface.
• Prime as required:

INSTALLING INSULATION BOARDS

General Rules:

• Achieve at least 40 per cent adhesive contact between each board and the wall.
• Stagger vertical joints and keep horizontal joints level.
• For EPS and PIR fill gaps greater than 2 mm with off cuts, not adhesive. Fill smaller gaps with low expanding PU foam.
• Maintain board flushness within plus or minus 2 mm on a 1 m straightedge

Special Pre‑Coating Step (Mineral‑Wool Only)

Before using either fixing method:

• Spread a continuous, very thin coat of fresh adhesive over the entire rear face of each mineral wool board. Work it firmly into the fibres with the flat of the trowel to obtain mechanical anchorage.
• Proceed immediately to the selected fixing method.
• Warning. Mineral wool must be fully pre-coated with adhesive. 
• Without this layer the adhesive bonds only the fibre tips, which can lead to system failure

Notch‑Trowel Method — flat substrates

• Scope: Substrates within about 3 mm on a 2 m straightedge.
• EPS/PIR: EPS and PIR. Apply adhesive in one pass with a 10 × 10 mm notched trowel. Use only Terrix PIR boards manufactured without a facer for EWI. Do not attempt to bond foil faced or plastic faced PIR.
• Mineral wool: After the precoating step, comb the same face with 10 × 10 mm notches.
• Place the board onto the wall, slide it slightly to collapse the ridges, press firmly and align.
• Verify coverage by lifting a trial board. Corners, edges and reveals may require higher coverage. Aim for 60 to 80 per cent in these exposed zones.
• Keep board joints tight and do not allow adhesive into the joints
  Ribbon and dab method for uneven substrates:

• Scope: Substrates with local deviation up to about 10 mm on a 2 m straightedge.
• Apply a continuous 50 mm bead of adhesive around the perimeter of the board, set 15 to 20 mm in from the edges to prevent squeeze out into the joints.
• Add six to eight dabs evenly across the central area. Each dab should be about 80 to 120 mm in diameter with a thickness after bedding of about 10 to 20 mm, depending on the deviation. Adjust the number of dabs proportionally for boards of other sizes.
• Mineral wool requires the precoating step before the dabs.
• Bed the board, align and level to the plane. Maintain tight joints and keep adhesive out of the joints.

Initial Curing

• Allow a minimum of 48  hours (weather-dependent) before carrying out any further work, including mechanical fixings, surface sanding, PU foam filling, or basecoat application. This time is required for the adhesive to achieve sufficient initial bond strength.
• Full adhesive strength develops in ≈ 28  days.

Mechanical fixings*

• Mechanical fixings are required as set out in the project design.
  For low-rise buildings, a typical density is 4 to 6 anchors per square metre with a pattern suited to the board size and substrate.
  For high-rise and exposed sites, the anchor density and pattern must come from a project-specific wind-load calculation in line with the applicable national code. Increase the density in the corner and edge zones and around openings.
• Install fixings only after the adhesive has cured sufficiently to prevent board movement. Fixing heads must sit flush with the board face without deforming the surface. Do not place anchors across board joints, and do not bridge movement joints. Drill to the required embedment, remove drilling dust and follow the anchor manufacturer’s instructions.* Fixing policy by insulation type. Mechanical fixings are mandatory for mineral wool systems. Use anchors approved for mineral wool with the plate diameter specified for the system. For EPS and PIR systems, mechanical fixings are optional unless required by the project specification or by local regulations.

Base Coat — Terrix® AD‑AB Reinforcement Layer

Fit Beads & Trims First

• Install corner beads, movement‑joint beads, stop beads and drip profiles before any AD‑AB is applied.
• Fix plumb and square, using the same adhesive or mechanical fixings specified for the system.
• Could you make sure mesh wings (where present) are clean and fully bonded?

Stress Patches

• Cut 250 × 300  mm mesh strips. Larger dimensions are recommended where space allows to improve crack resistance.
• Embed diagonally (45 °) across every corner of windows, doors and other openings using fresh AD‑AB.

Reinforcing Coat

• First pass: Apply 3–4  mm of AD‑AB with a stainless‑steel trowel over an area no wider than the mesh roll.
• Mesh embedment: Embed the mesh into fresh basecoat; overlap adjacent strips by at least 100  mm. Mesh must be fully embedded and not visible.
• Levelling pass: Immediately add mortar to produce a total dry thickness of 4–6  mm.
• Finishing: When touch‑dry, plane off ridges. Light sanding is permitted once fully dry, but the mesh must remain completely covered at all times.

Curing & Protection

• Protect the fresh coat from rain, frost, strong wind or direct sun
  for ≥  48–72  h.
• Ideal curing climate: +10  °C  to  +25 °C, ≤  80  %  RH.

Quality Checks

• Mesh must be fully embedded in the upper third of the reinforcement layer. No voids, blisters or surface irregularities are permitted.
• Pull‑off value (adhesive to the substrate) ≥ 0.08  MPa (test on site if applied to old or non-standard substrates).

Subsequent Finishes

Once the base coat has fully cured (typically 5–7  days, weather‑dependent):

• Apply Terrix® primers and decorative renders or other specified finishes as per the system design.

 Environmental & Safety Requirements

• Application temperature +5 °C  to  +25  °C  (air and substrate); avoid work during expected frost, driving rain or intense sun.
• Never modify mixes with extra water or additives.
• Store bags in a  dry place, off the ground, at  5–25  °C.
• Provide appropriate PPE, dust extraction and secure scaffolding.
• Follow local ETICS/EWI regulations; keep SDS documents on site.