Introduction
Standard crack injection relies on drilling angled holes and setting mechanical packers. But sometimes drilling is not an option. The element may be too thin, the substrate too valuable to perforate (think natural stone or heritage masonry), or the surface finish too important to disturb. In other cases you simply want a faster, lower-disruption repair on hairline cracks.
For all of these, there are two excellent drill-free techniques: surface adhesive packers and wedge packers. This guide explains how each works and when to use it.
Why You Might Avoid Drilling
- Thin sections where a drilled, angled hole would weaken the element or break through.
- Natural stone, granite, and heritage masonry that must not be perforated for structural or aesthetic reasons.
- Visible surfaces where drill holes would be unsightly.
- Hairline cracks too fine to justify the time of drilling and setting mechanical packers.
- Speed — gluing or tapping a packer in place is faster than drilling.
The injection principle is unchanged — only the way you get resin into the crack differs. If you are new to the method, start with our Complete Guide to Waterproofing with Injection Grouting.
Option 1: Surface Adhesive Packers
Surface adhesive packers (also called surface ports) are glued directly over the crack with epoxy paste, so the resin enters the crack through the port without any hole being drilled into the substrate.
- Surface Adhesive Packers — bonded to the concrete surface with epoxy adhesive, with non-return nipples to prevent resin flow-back. Ideal for hairline to wider cracks in dry conditions, injected at low pressure.
- Adhesive Packer — a surface-glued plastic packer with an M8 internal thread and an enclosed steel conical M8 nipple, for crack injection on substrates that must not be drilled.
Because they work at lower pressures, surface packers pair naturally with epoxy crack repair. A low-viscosity epoxy like Sealgrout 55 LP flows into fine cracks through these ports — see Epoxy Injection for Structural Crack Repair for the full method.
How to Use Surface Packers
- Clean the crack and the surface around it.
- Position the ports along the crack, spaced roughly to the element thickness, and bond each with epoxy paste.
- Cap the crack between ports with epoxy paste so resin builds pressure inside rather than weeping out.
- Let the paste cure, then inject from one end, capping each port as resin reaches the next.
- Cure, remove, and grind flush.
Option 2: Wedge Packers
A wedge packer is driven directly into the crack itself — no pre-drilled hole at all. It is the fastest drill-free method and works on a remarkable range of materials.
- Steel Wedge Packer — a compact steel wedge with a screwed-in M5 cone nipple and integrated check valve. Driven straight into the crack, it suits concrete, granite, hollow block, brick, sandstone, and even wood, and is rated for injection pressures up to 50 bar.
This makes the wedge packer ideal for masonry and stone where you want meaningful injection pressure but cannot drill. Because it accepts up to 50 bar, you can use it with both epoxy and many PU resins.
How to Use Wedge Packers
- Open the crack mouth slightly if needed and clean it.
- Tap the wedge packer firmly into the crack so the check valve faces outward.
- Connect the gun and inject, working along the crack from one packer to the next.
- Remove after cure and patch the crack mouth.
Surface vs Wedge: Which to Choose?
| Factor | Surface Adhesive Packers | Wedge Packers |
|---|---|---|
| Drilling | None (glued on) | None (driven into crack) |
| Best pressure range | Low | Up to 50 bar |
| Best substrate | Dry concrete, fine cracks | Masonry, stone, brick, wood |
| Typical resin | Low-viscosity epoxy | Epoxy or PU |
| Speed | Fast (cure time for adhesive) | Fastest |
For drilled, high-pressure work where you can drill, mechanical steel or aluminium packers are still the better choice — compare them all in How to Choose the Right Injection Packer.
A Note on Dispensing
Surface packers and capping pastes are often dispensed with a sealant gun. Our Manual PU Sealant Gun CE102 and the heavier-duty CE102 Advanced handle 600ml cartridges for capping and bonding work, while the Epoxy Anchor Gun 380ml dispenses two-component anchoring mortars.
Conclusion
You don’t always need a drill to inject a crack. Surface adhesive packers glue over the crack for clean, low-pressure epoxy injection on dry concrete, while wedge packers tap straight into the crack for fast, drill-free repair of masonry and stone at pressures up to 50 bar. Both keep delicate or valuable substrates intact while still delivering a proper, pressure-injected seal.
Get Started
Have a waterproofing or crack-repair project? Request a free quote and our technical team will recommend the right products and method for your site.
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