Rawlplug resin: What are they and how to use them?

Rawlplug resin is a chemical anchoring solution that transforms those weak points in brick or concrete into rock-solid fixings. Instead of relying solely on friction, these resins bond chemically with the substrate, creating a secure connection that feels as if the fixture is part of the structure itself.

In this guide, we’ll break down what Rawlplug resin is and explore the key products in the range, from R-KEM II Polyester Resin to R-KEX II Epoxy Resin and R-KER II Vinylester Hybrid Resin. So let’s begin.

What is Rawlplug resin?

At its most simplified description, Rawlplug resin is a two-part adhesive anchoring system. Each cartridge contains a resin base and a hardener, which, when mixed in the nozzle, react chemically to create a solid bond that locks fixtures into place. Where expansion anchors rely on pressure against the sides of a drilled hole, resin distributes load evenly.

Key benefits include:

Works in concrete, solid brick, hollow block, and masonry: Rawlplug resin can be used across a wide range of substrates, from anchoring heavy machinery in concrete floors to fixing shelving or handrails in hollow brick walls.
Provides strong, long-lasting bonds: The chemical reaction between resin and hardener creates a durable connection that maintains load-bearing capacity over time, even in high-traffic areas or under constant vibration, such as securing balustrades, structural supports, or industrial equipment.
Ideal for heavy-duty or structural applications: Rawlplug resin is suitable for tasks that need maximum strength and reliability, including bridge construction, and fastening steel columns or beams in commercial and industrial buildings.
Suitable for use in damp, cold, or chemically exposed environments: Whether you’re working in basements, with outdoor exposed walls, or near chemical storage areas, Rawlplug resin maintains its bond and performance, resisting moisture ingress, frost, or corrosive substances.

Types of Rawlplug resin

You can get a few different types of Rawlplug resin that are made for specific site conditions and use cases. These various types are engineered with different ingredients to give them specific characteristics.

Polyester resin: Quick to cure, and perfect for light-to-medium-duty fixings.
Vinylester hybrid resin: Combines speed and strength, with excellent resistance to chemicals, heat, and damp environments.
Epoxy resin: Designed for the heaviest loads and long-term durability.

Each type has its place, but understanding the strengths and limits of each will save time, money, and potentially costly installation errors.

Rawlplug R-KEM II-410 (Polyester Resin)

Rawlplug’s R-KEM IIis the go-to general-purpose resin. Styrene-free and ETA-approved, it’s versatile enough for 15 different substrates, including non-cracked concrete and natural stone and is known for its quick curing time.

Key points:

Styrene-free formulation (low odour, safer to use indoors)
Approved for non-cracked concrete, stone, brick, and block
Quick curing — ideal for jobs on tight schedules, such as installing handrails in commercial buildings between work shifts.

Rawlplug R-KEX II-385 (Pure Epoxy Resin)

If you’re looking for uncompromising strength, R-KEX II-385 is the answer. This pure epoxy system is built for the most demanding structural applications like bridges and anchoring industrial equipment. It performs even in water-filled holes and is highly resistant to chemicals.

Key points:

Highest load capacity in the Rawlplug range
Works in cracked and non-cracked concrete
Can be used in wet and water-filled holes
Excellent chemical and environmental resistance
Longer curing time compared to polyester or vinylester resins

Rawlplug R-KER II-400 (Vinylester Hybrid Resin)

Sitting between polyester and epoxy, the R-KER II-400 Vinylester Hybrid Resin provides both speed and strength. Fire-rated and resistant to both moisture and high temperatures, it’s an ideal choice for structural fixings exposed to the elements.

Key points:

Approved for cracked and non-cracked concrete
Strong resistance to chemicals, damp, and temperature extremes
Fire-rated for use in critical safety applications, such as securing fire-rated steel supports in public buildings
Perfect for steel constructions, facades, and heavy railings

How to use Rawlplug resin

The bond strength of Rawlplug resin depends on preparation, application, and curing, and all of these steps must be performed accurately to achieve the desired results. Every step matters, from drilling the hole to twisting in the anchor rod.

First off, here are the tools and materials you’ll need:

Hammer drill with appropriate drill bits, such as carbide-tipped masonry bits for concrete or SDS-plus drill bits for solid brick and block
Cleaning brush and blow pump (or compressed air)
Resin dispenser gun (manual or pneumatic)
Mixing nozzles
Threaded rods or anchor studs
PPE: gloves, goggles, and ventilation

Step 1: Hole preparation

This is the first and one of the most crucial steps.

Drill to the recommended diameter and depth for your stud size.
Clean the hole. You could use the 4x4x4 principle (blow out 4 times with a pump, brush the sides 4 times, and then blow out 4 times again), or the 2x2x2 principle for compressed air.
Make sure there’s no dust left, as the residue can weaken the bond.

Step 2: Resin preparation & application

When the hole is ready, it’s time to prepare the resin cartridge.

Insert the cartridge into the dispenser gun
Attach the mixing nozzle securely
Extrude and discard the first 10–12cm of material until the mix is uniform
Insert the nozzle into the bottom of the hole
Fill holes to:

70–75% depth for solid substrates
100% with mesh sleeves for hollow substrates

Slowly remove the nozzle as you fill to avoid air gaps

Step 3: Rod installation

Now it’s time to insert the rod before the resin begins to set.

Push in the threaded rod with a slow twisting motion
This ensures resin coats the threads and distributes evenly
Don’t worry about excess resin, as this can be trimmed when it’s cured

Step 4: Curing & load application

Here’s where it gets a little bit different depending on the product you’re using, as these different types of resin have different cure times, which can also be affected by the environment and substrate temperatures

Vinylester (R-KER II): At moderate temperatures (10–20 °C), it typically takes 45–90 minutes.
Polyester (R-KEM II): Between (10–20 °C), it takes 45–90 minutes.
Epoxy (R-KEX II): When the Resin temperature and the concrete temperature are between (10–20 °C), it can take anywhere from 5 hours to 18 hours.

For more specific curing times, dependent on a range of temperatures, refer to your product’s data sheet.

Safety precautions

When working with chemical anchors, it’s vital to take the correct safety precautions to protect yourself from potential respiratory issues or skin irritation if substances come into contact with your hands or lungs. They’re also in place to protect the environment from potential harm. On Rawlplug resin’s safety data sheets, the following specific precautions are listed to reduce risks and ensure a safer working environment.

Wash your hands thoroughly after handling.
Do not breathe dust. Use in well-ventilated areas and use an appropriate respirator when this isn’t possible.
Wear protective gloves/protective clothing/eye protection/face protection.
Keep out of reach of children.
Avoid release to the environment. If spilt, contain the spillage using bunding. Inform the authorities in the event of spillage entering the sewers or watercourses. Uncured product should be disposed of as chemical waste in a licensed facility, in accordance with local regulations of environmental protection and binding legislation on recycling
If it gets into your eyes, rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
If it comes into contact with your skin, wash with plenty of water. R-KER II specifies washing with plenty of soap and water.

Choosing the right Rawlplug resin for your project

So, now we’ve explored Rawlplug resin, which is the best for your project? As we know, they all have varying characteristics, so here’s a little bit of guidance on when they could be used. Consider:

Substrate type: cracked or non-cracked concrete, hollow block, damp conditions
Load capacity: medium-duty vs heavy-duty structural loads
Environment: temperature extremes, fire safety, chemical exposure

Quick guide:

For everyday fixings in brick or stone, consider R-KEM II.
For critical heavy loads, consider R-KEX II-385.
For outdoor structural projects with moisture/chemicals, consider R-KER II-400.

Ready to start your project with Rawlplug resin?

Choosing the resin for your project isn’t just a technical detail. It’s an important part of delivering safe, compliant work that lasts as long as you need. If you’re a construction professional, we have the Rawlplug resin that's perfect for the job.

Explore our full range of resin anchors to find the perfect solution for your project. If you have any questions about our products, whether it’s about finding the one best suited to your application or anything else, please contact us today. Our team is on hand to guide you towards the right fixings for professional results.

By Katie Taylor