Terraco’s concrete repair system has two parts. Terramix is a ready-mixed repair mortar and plaster that rebuilds and levels the surface, in three grades by thickness. Terraroc FC is a thin micro-finish render that gives the repaired concrete a uniform new face. Short answer: use the Terramix grade that matches the depth you need to fill (Coarse 5 to 15 mm, Standard 3 to 5 mm, Fine 1 to 3 mm), then finish with Terraroc FC at 0.5 to 3 mm. On concrete that only has fine cracks and surface defects, Terraroc FC can go straight on. This guide is based on Terraco’s UAE technical data sheets.
Choosing the right product by depth
| Product | Layer thickness | Mixing water per 25 kg | Consumption |
|---|---|---|---|
| Terramix Coarse | 5 to 15 mm | 5.5 to 6.0 L | About 1.8 kg/m² per mm |
| Terramix Standard | 3 to 5 mm | 6.0 to 6.5 L | About 1.8 kg/m² per mm |
| Terramix Fine | 1 to 3 mm | 6.0 to 6.5 L | 1.8 kg/m² per mm |
| Terraroc FC | 0.5 to 3 mm | 8.25 to 8.75 L | 1.5 kg/m² per mm |
All four come in 25 kg bags in grey or white and are for interior and exterior use.
Terramix: rebuild and level
Terramix is a powder of hydraulic and organic binders with washed sand or quartz. Terraco lists it for plastering and repairing cast-in-situ concrete, lightweight concrete, dense fair-faced concrete, blockwork and brickwork, on walls and ceilings. The data sheet gives adhesion above 0.5 N/mm² and maximum shrinkage of 0.13%. Terramix Fine adds strength figures of more than 4.0 N/mm² in flexure and more than 6.5 N/mm² in compression. The finished surface can be painted or wallpapered, and Terramix is also the basecoat in Terraco’s spray plastering system.
Terraroc FC: the new face
Terraroc FC is the final coat in the system. Its data sheet gives compressive strength of at least 20 N/mm² and flexural strength of at least 5 N/mm² (EN 1015-11), tensile adhesion of at least 1 N/mm², and a set time of 1 to 2 hours. It is sprayed on and levelled with a steel float, then finished smooth with a damp wooden float or foam.
Step by step
- Prepare. Remove loose particles, dust, dirt, grease, oil and paint. Dampen absorbent surfaces.
- Prime if needed. In extreme heat or on very absorbent surfaces, Terraco specifies Terrabond A: diluted 1:5 as a primer under Terramix Fine, or added to the mixing water at 1:15 for Terramix. Our Terraco primer guide covers the ratios.
- Mix Terramix. One 25 kg bag with the water for its grade, 3 to 5 minutes with a high-speed mixer or hand agitator. Stand 5 minutes and re-stir.
- Apply and level by trowel and steel float, within the grade’s thickness range. Once set, smooth with a damp wooden or foam float and brush off loose particles when dry.
- Cure. Keep the surface moist for the first 48 hours.
- Reface with Terraroc FC. Soak the substrate thoroughly, mix 25 kg with 8.25 to 8.75 L of water, spray on 0.5 to 3 mm, level and finish. Keep moist for 48 hours.
How many bags
| Thickness | Terramix, m² per 25 kg | Terraroc FC, m² per 25 kg |
|---|---|---|
| 0.5 mm | – | 33 |
| 1 mm | 13.9 (Fine) | 16.7 |
| 2 mm | 6.9 (Fine) | 8.3 |
| 3 mm | 4.6 | 5.6 |
| 5 mm | 2.8 | – |
| 10 mm | 1.4 (Coarse) | – |
Example: levelling 50 m² of wall at 5 mm with Terramix Standard needs about 450 kg, or 18 bags. Refacing the same wall with 1 mm of Terraroc FC needs about 75 kg, or 3 bags. These are our own calculations from Terraco’s consumption figures; add extra for uneven areas and waste.
What comes next
Once repaired and cured, the wall is ready for its finish. On a facade, that is usually a primer plus Terracoat or a mineral render such as Terol, compared in Terol vs Terracoat. For an insulated facade, see EIFS Alpha vs Perma vs Polar. For a tank or wet room, see Terracrete vs Weathercoat GP.
Frequently asked questions
Is this for structural repairs?
Terraco’s data sheets describe Terramix as a repair mortar and plaster and Terraroc FC as a micro-finish render. Where concrete is spalling or reinforcement is exposed, get a structural engineer’s assessment and repair specification first.
What about small cracks before painting?
For cracks and small defects on rendered walls, a ready-mixed filler is quicker. See our guide to filling exterior wall cracks with Handycoat Exterior.
Buying Terraco repair products in Sharjah and Dubai
Al Tashteb Al Saree is an authorised Terraco distributor and supplies all Terramix grades and Terraroc FC direct from the manufacturer. Message us on WhatsApp with the area, thickness and colour. You can also browse every Terraco product we supply.
Sources
- Terraco: Terramix technical data sheet (PDF, version 10.2011)
- Terraco UAE: Terramix Fine technical data sheet (PDF)
- Terraco UAE: Terraroc FC technical data sheet (PDF, 2023)
Retrieved 1 November 2026. Check the latest Terraco data sheet before specifying. Quantities are our own calculations. The main image is illustrative.
