TERRIX® AD-FA
adhesive/base coat
flexible
A dry, mineral-based flexible adhesive formulated with modified hydraulic and polymer binders, enhanced with performance-boosting additives for both manual and machine application. It is specifically recommended as part of the TERRIX® EWI Systems, designed to bond insulation to flexible substrates such as plywood, OSB board, MgO board, and more.
Benefits
Main properties:
- Universal Flexible Adhesive for Timber/Steel Frame Systems: Specifically formulated for flexibility, this adhesive minimises the risk of bond failure caused by natural movement in timber and steel frame systems, ensuring long-term durability and reliability.
- High Strength: Provides robust mechanical strength, delivering excellent performance under stress, ensuring that the adhesive remains strong and secure throughout the application’s life.
- Water and Frost Resistant: Designed to resist water penetration and frost damage, this adhesive ensures the bond remains intact even in the harshest conditions, protecting against both moisture and freezing temperatures for long-lasting durability.
- For Indoor and Outdoor Use: Engineered for versatile application, this adhesive is suitable for both indoor and outdoor environments. It offers reliable performance in a wide range of conditions and ensures ease of use across various construction settings.
Technical Data
Base binder: hydraulic and polymer binding agents with modifiers;
Mixing proportions: 6.5 litres of water per 25 kg of mortar;
Consumption: approx. 5 kg/m2;
Coat thickness: min. 4 mm;
Application time after adding water: max. 3 hours;
Bulk density: 1350 kg/m3;
Compressive strength: ≥ 3.5 N/mm2;
Adhesion to insulation: ≥ 0.08 N/mm2;
Adhesion to concrete: ≥ 0.25 N/mm2;
Water absorption: Wc 1;
Water vapour permeability: μ≤25;
Reaction to fire: A2 – s1,d0;
Temperature of application (air and substrate): from +5°C to +25°C;
Packaging: single-use paper packaging contains 25 kg of the product;
Storage: store in the tightly sealed original packaging in a dry place, protected from moisture;
Shelf life: 12 months from the production date (factory-sealed packaging).
CAUTION: Keep the product out of reach of children.
Application
PRODUCT PREPARATION MIXING & WORKING TIME
|
Parameter |
Requirement |
Purpose/comment |
|---|---|---|
| Water ratio |
6.5 ℓ of clean water per 25 kg of powder |
Do not exceed the limit. |
|
Mixing |
Introduce powder slowly into the water while stirring ≤ 400 rpm until completely lump‑free |
Low speed prevents air entrapment. |
|
Maturation |
Rest the mix for ≈ 5 min, then re‑mix briefly |
Ensures full wetting of binders. |
|
Pot life |
≈ 3 h at +20 °C / 65 % RH |
Higher temperature ⇒ shorter pot life. |
|
Open time |
≈ 20 min between spreading the mortar and positioning the board or embedding the mesh |
Work within this window. |
Never re‑temper a stiffening mix with extra water. Prepare only what can be applied inside the pot‑life period.
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:
|
Substrate |
Recommended Terrix® primer |
|---|---|
|
Highly absorbent mineral |
PR‑DP deep‑penetration |
|
Moderately absorbent/universal |
PR‑UA‑Q acrylic with quartz |
|
Porous silicate |
PR‑ST‑LB silicate |
| OSB / timber sheathing |
PR‑BB bonding‑bridge (mandatory) |
INSTALLING INSULATION BOARDS
General Rules:
- Achieve ≥ 40 % adhesive contact between board and wall.
- Stagger vertical joints; keep horizontal joints level; EPS, PIR- fill gaps > 2 mm with off‑cuts, not adhesive. Smaller gaps to be filled with low-expanding PU foam.
- Maintain board flushness (±2 mm on a 1 m straight‑edge).
Special Pre‑Coating Step (Mineral‑Wool Only)
Before using either fixing method below:
- Spread a continuous, very thin coat of fresh adhesive over the entire rear face of each mineral‑wool board.
- Warning: Mineral wool must be fully pre-coated with adhesive. Without this layer, adhesion is limited to the fibre tips, leading to potential system failure.
- Work it firmly into the fibres with the flat of the trowel to obtain mechanical anchorage.
- Proceed immediately to the selected fixing method.
Notch‑Trowel Method — flat substrates
- EPS/PIR: Apply adhesive in one pass with a 10 × 10 mm notched trowel.
- Mineral wool: after the pre‑coat, comb the same face with the 10 × 10 mm notches.
- Place the board onto the wall, press firmly and adjust as needed to ensure good adhesion and alignment. Check that at least 40 % of the board has adhesive contact.
Ribbon‑and‑Dab Method — uneven substrates
- Apply a continuous 50 mm bead of adhesive around the perimeter of the board, set slightly in from the edge to avoid squeezing out adhesive when pressing the board onto the substrate.
- Add 8–12 cm diameter dabs evenly over the central area.
- Mineral wool requires the pre‑coat before this step.
- Bed the board, align and level.
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 (if specified)
- Typical rate 4–6 anchors /m²; follow the project design.
- Install fixings only after a minimum curing time of 48 hours. Anchor plates must be set flush with the board surface. Before fixing, sand the board surface to ensure it is level. Follow the anchor manufacturer’s installation instructions.
Board dressing (single operation before base coat)
|
Board type |
Dressing tool |
Aim |
|---|---|---|
|
EPS |
Rasp plane |
Remove high spots/oxidation film |
|
PIR |
Medium‑grit sandpaper |
Provide a flat, matt surface |
|
Mineral wool |
Stainless‑steel rasp |
Level and consolidate surface fibres |
Remove all dust with a soft brush or vacuum.
Base Coat — Terrix® AD‑FA Reinforcement Layer
Fit Beads & Trims First
- Install corner beads, movement‑joint beads, stop beads and drip profiles before any AD‑FA 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‑FA.
Reinforcing Coat
- First pass: Apply 3–4 mm of AD‑FA 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.
Case study
Terrix PL-SX Spray Plaster
Terrix PL-SX Spray Plaster Ready-to-use plaster coat for machine levelling of interior walls and ceilings. ⋅ Chemically bonded product ⋅ No risk of cracking or flaking ⋅ Chemical accelerated set
Polymer-silicate premium paint from Terrix at NEW VICTORIA project by VINCI Construction
Terrix® paint range offers unique properties not available from other paints on the market. Based on innovative Swiss technology combining silicate and dispersive binding agents. https://terrix.co.uk/wp-content/uploads/2024/12/Terrix-Mac-Vic-V-Small-File-Size.mp4 How is it
Terrix Repair and Crack Restoration Systems
Terrix Repair and Crack Restoration Systems Terrix® systems offer a uniquely chemical-bonded product: - flame retardancy - no delamination - no cracking or peeling - natural algae resistance -
Regeneration project for Conway Council, in a conservation area
Solution The right system needed to be used. Hence the Terrix system using Eps insulation with the Terrix Polymer-Silicate renders is the perfect choice. The renders, based on Silicate,
