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Watco Concrex Epoxy Repair Mortar

Permanent granite hard repairs where ordinary mortars fail

  • Virtually indestructible
  • Impervious and non-dusting
  • Mix and apply in minutes
  • So strong it can be feather edged

Watco Concrex gives superior strength and durability to any repair due to its unique resin rich formulation. We know our customers are going to put it to the test with constant heavy traffic, so our formula includes an epoxy novolac resin blend - the expensive component that binds the material and gives it its industrial toughness. We haven’t just thought about the resin though. Every component in the Concrex formula has been chosen to achieve unrivalled strength. We’ve used several sand particle sizes that interlock together for a stronger bond and a smoother finish. This combination means that you can carry out repairs down to a feather edge without the need for a primer. 

We recommend using Watco Tack Coat for intricate repairs or high-impact areas such as broken expansion joint edges, step nosings or when applied as a thin screed (5mm thick) for resurfacing. Using Tack Coat in these situations not only ensures complete adhesion, but it makes it easier for you to get a professional finish.

For over 50 years, Concrex has been the leading epoxy repair mortar and millions of kilos of it are reinforcing and protecting concrete floors, steps and ramps across Europe and the rest of the world. It should be regarded as permanent, which is why we consider it the benchmark for repairing concrete. It’s a versatile formula that results in a granite-hard finish that is impervious and non-dusting. After all, it’s what you should expect from our top performing repair mortar.

Recommended areas of use

  • Holes
  • Spalled expansion joints
  • Worn floors
  • Damaged steps
  • Fitting guide rails
  • Reforming a slope


  • Epoxy novolac resin formula for added chemical resistance and mechanical strength
  • It comes part mixed which makes it quicker and easier to use on site
  • Includes a grey curing agent, so it's easy to tell when it is thoroughly mixed
  • Outstanding strength and should be regarded as permanent
  • Can be moulded into shape, making it ideal for repairing damaged step nosings
  • Takes heavy traffic after 12-16 hours at 20°C. Full strength achieved at 5mm thick
Properties Incredibly tough, granite–hard finish, chemical–resistant, anti–slip, priming not normally required, impervious and non-dusting, may be feather-edged, cures in 3–6 hours at ambient temperatures, ready for heavy traffic in 8–12 hours.
Suitable for Floors, ramps, steps.
Finish Smooth, impervious surface.
Interior or Exterior Interior and exterior.
Primer required Tack Coat Primer is essential for shallow applications and screeding.
Coverage 1.2m² per 10kg at 5mm thick.
Curing time 3-6 hours.
Pot life 30 minutes.

Surface preparation

The surface must be clean, dry and free from loose material. Sweeping the area with a broom or wire brush is usually enough to remove any dust and dirt. If the area is contaminated with oil or grease, we recommend using Watco Bio-D to clean the damaged surface. Bio-D is an industrial degreaser that is tough on oil and grease, but easy for the environment. It's biodegradable, low odour and can easily be washed away without harming the surrounding concrete or drainage systems nearby.

To ensure maximum adhesion, we recommend using Watco Tack Coat with all applications. However, this is especially important for shallow repairs and screeding. The surface will need to be dry, or slightly damp before applying. If used on areas that are extremely wet, or where water is pooling, the water will dilute the primer and you won’t get the same strength properties.


Each bucket contains a part-mix of Concrex powder, sand and epoxy resin and bottles of curing agent. Empty the mixture into a Watco Concrex Mixing Tub. Create a well in the middle, then pour in the curing agent into the middle, ensuring all the bottles are completely empty.

Wearing rubber gloves, mix the components together by hand, or use a Mix & Apply Trowel until you get an evenly coloured grey mixture. We've made it easy by adding the grey colour to the curing agent, so you'll know when it's thoroughly mixed. For large quantities, we recommend using a mixer to save you time.


Apply the mixed mortar to the damaged area, either by hand or trowel. Slightly overfill the hole then use a 10" Steel Float to compress the mortar into the hole. If you wipe the trowel with White Spirit, it will help you get a professionally smooth finish and avoid the mortar from sticking.


Case studies

£84.80 (Ex VAT)

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Specialist alternatives

Applying in cold conditions?

Complete your maintenance projects all year round

Our chemists have developed cold curing products with the latest resin technology so you can continue with your repair projects all year round.

All cold cure

Watco Concrex Sub Zero


For essential repairs during the winter months

£100.60 (Ex VAT)

Need chemical resistance?

Ensure your floor surface is resistant to chemical attack

if you are repairing an area where chemicals are stored or regularly used, you will need to ensure the repair material can stand up to chemical attack.

All chemical resistance

Watco Concrex Acid Strength

Permanent floor repairs with excellent chemical resistance

£100.60 (Ex VAT)

Need to fill a deep hole?

Get the right product for filling holes deeper than 50mm

Our Deep Fill alternatives allow you to apply them at much thicker depths in one application. Meaning you can get a more economical formula that delivers the same strength and reduces downtime.

All hole repair

Watco Concrex Deep Fill

Economical and strong repair formula for deep holes

£109.30 (Ex VAT)

Need a flexible repair?

Give flexibility to areas prone to movement

Flexible formulations are ideal for areas where vibration, movement or impact may occur. The material moves with the substrate to avoid it breaking up or cracking.

All flexible

Watco Concrex Flex


Impact and crack resistant floor repair

£108.50 (Ex VAT)

Repairing asphalt?

Choose the right product for your surface type

If you are repairing an asphalt substrate, then we have a range of bitumen based products that help blend in with the existing environment.

All asphalt repair

Watco Concrex Asphalt Repair


Ultra-strong repairs to damaged concrete and asphalt

£103.60 (Ex VAT)

Tools and accessories

Trowels and Floats

Trowels and Floats

Ideal for mixing, applying and levelling repairs

From £3.20  (Ex VAT)

Watco Concrex Application Kit

Watco Concrex Application Kit

Everything you need for applying Concrex

From £14.50  (Ex VAT)

Watco Tack Coat

Watco Tack Coat

High strength 100% solids epoxy resin adhesive primer

From £22.50  (Ex VAT)

Wire Brush & Scraper

Wire Brush & Scraper

A useful tool for removing rust and old coatings

£2.50  (Ex VAT)

Concrex Mixing Tub

Concrex Mixing Tub

Ideal for mixing Watco Concrex

£10.20  (Ex VAT)

What our customers say

Help & Advice

Contact our friendly and professional Technical Advisors for expert help and advice for your project. You can give us a call on 01483 418 418 or email

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