Resin Fixings & How to Use Them

How to Use Chemical Fixings and Resin Anchors

In this guide learn all about how to use chemical fixings and resin anchors for fixing to concrete and brick/blockwork where using traditional expanding bolts and wall plugs may involve splitting and cracking the material you are fixing into.

Chemical and epoxy resin fixings and anchors are a relatively new concept and essentially offer an alternate way of fixing items other than using screws, bolts and the similar.

Used correctly, chemical fixings and anchor resins produce an extremely strong fixing as they essentially bond to their surroundings. Find out all about them and how to use them below.

When to Use Chemical Fixings and Resin Anchors

If you need to fix close to the edge of a brick or blockwork drilling and using screws and bolts which expand in their associated wall plugs may crack or split the masonry.

The way to get over this is to use chemical fixings or resin anchors injected into a pre-drilled hole.

A section, or stud, of threaded bar is then screwed and bonded into the hole. The resin goes very hard, binding the thread to the masonry and leaving a short length of thread sticking out onto which you can bolt your balcony.

Resin anchors will take high loads, but preparation is important!

How to Fix Bars, Studs and Anchors Using the Chemical Fixing Method

Four easy stages complete this operation, and these are as follows:

Studs are generally available in 8, 10 and 12mm sizes. Dowels, for reinforcement or joining are available in high tensile plated steel or epoxy-glass in 6 – 25mm diameters.

Masonry drill bits are required for this and you need to allow a standard over-size of at least 4mm on the diameter – an 8mm stud will require a 12mm drill bit and so on.

Proprietary brushes are available, or you can use air, by blowing down a tube (don’t suck, close your eyes and wear a dust mask and eye protection) or using a compressor. If you have an old vacuum cleaner handy this can also work well.

Ensure the gun is fitted with an extension tube of the correct length and diameter to reach the bottom of the hole. Inject gently, slowly removing the tube from the hole, to deposit resin without trapping air.

For accurate, waste free injection pre-mark the tube with tape, so that you can stop operating the trigger when the tape appears. Set the tape at a distance from the tube end to allow for the resin that will be displaced by the bar.

Various applicator skeleton guns are available, depending upon which resin you choose. You may already have the basic 300cc and/or 400cc skeleton guns, which are used with certain resin anchor products.

Pure Epoxy – it mixes in the nozzle – ideal for anchoring bolts and bars

Polyester Anchor Resin – faster than Epoxies, ideal for rapid anchor setting

Make sure that the tape goes over the part required to take the nut, to avoid resin contamination, which might block the threads.

Take the stud in a gloved hand and slowly rotate whilst pushing it into the resin filled hole.

Once the anchor bolt, stud or threaded bar has been inserted into the drilled hole that is now full of resin, before you can fit your balcony you will need to leave for the manufacturers specified time for the resin to set. This should be stated on the resin container.

Once it has set rock hard you can then go ahead and complete the job by fitting your balcony in place.

Types of Resin

There are two main types of resin fixings:

• Epoxies
• Polyesters

With most manufacturers these are available in fast (3 – 6 minutes), medium (15 – 30 minutes) and slow setting (4 – 6 hours) formulations in three main pack types;

• Single cartridge tube – no hand mixing required – two resins inside in a plastic bag – fits standard skeleton guns – resins mix in the nozzle, inside a spiral, which is replaced if the resin hardens before the tube is exhausted
• Dual cartridge tube – no hand mixing required – two resins inside twin plastic tubes linked together – requires a specific skeleton gun for each type, depending on cartridge size and mix ratio – resins mix in the nozzle, inside a spiral, which is replaced if the resin hardens before the tube is exhausted

Below is a video of an example of how chmical resin is used (Based on R-Kem2 from screwfix)