A guide to resin-bonding patios.

Unlike loose gravel, resin bonding provides a fixed surface that is slip-resistant and visually striking. It is particularly effective for upgrading existing outdoor spaces where the substrate is still structurally sound but aesthetically dated.

What Does the Work Involve?

• Site Assessment: Checking the existing base for structural integrity, drainage levels, and moisture content.
• Surface Preparation: Deep cleaning the substrate via industrial pressure washing to remove moss, oil, and loose debris.
• Crack Repair: Filling minor fissures with epoxy mortar to prevent "reflective cracking" in the new finish.
• Priming: Applying a specialist primer to ensure maximum adhesion between the old surface and the new resin.
• Resin Application: Spreading a layer of polyurethane resin evenly across the patio using a notched squeegee.
• Aggregate Broadcasting: Scattering the chosen stone (usually 1-3mm or 2-5mm) over the wet resin until it is completely "blinded."
• Final Sweep: Removing excess, unbonded stone once the resin has fully cured.

Typical Costs

Prices for resin bonding are generally lower than resin-bound systems because the layer is thinner and the installation process is faster. However, the quality of the resin (UV stable vs. non-UV stable) significantly impacts the final quote.

Factors affecting the price include the size of the area, the choice of aggregate (rare quartz vs. standard flint), and the condition of the existing substrate. If the base requires significant levelling or repair, costs will increase toward the higher end of the scale.

How Long Does It Take?

• Preparation & Cleaning: 0.5 to 1 day (requires drying time before resin application).
• Installation (Small/Medium Patio): 1 day.
• Curing Time: 4 to 12 hours for foot traffic; 24 hours for heavy furniture.
• Total Project Duration: Typically 2 days, assuming dry weather conditions.

DIY or Professional?

While DIY resin kits are available, professional installation is strongly recommended for patio bonding. The resin has a very short "open time," meaning it begins to set rapidly; any hesitation or uneven spreading will result in visible joins and "bald" patches. Furthermore, professionals use industrial-grade equipment to ensure the surface is perfectly clean, which is the most critical factor in preventing the resin from peeling off in the future.

Expert Tip: Always ensure your installer uses UV-stable resin. Non-UV resins are cheaper but will turn a sickly yellow or brown when exposed to sunlight within just a few months.

Choosing the Right Tradesperson

• Check Portfolios: Look for photos of "resin bonded" (scatter) projects specifically, not just "resin bound" (mixed).
• Verify Experience: Ask how many years they have worked with resin systems, as temperature and humidity control are vital for a successful bond.
• Ask about UV Stability: Ensure they explicitly quote for UV-stable polyurethane.
• Questions to Ask:
  • Do you offer a guarantee against delamination (peeling)?
  • How do you handle drainage if the current patio has standing water?
  • What happens if it rains during the installation?

UK Regulations

• SUDS Compliance: Unlike resin-bound surfacing, resin bonding is not naturally permeable. If you are covering a large area, you must ensure adequate drainage (soakaways or channels) to comply with Sustainable Urban Drainage Systems (SUDS) regulations.
• Planning Permission: Generally not required for patios unless you are significantly changing the height or the drainage runoff impacts public highways.
• Health and Safety: Installers should follow COSHH guidelines when handling resins and wear appropriate PPE.

Common Problems

• Reflective Cracking: If the underlying concrete base cracks, the thin resin-bonded layer will crack in exactly the same place.
• Loose Stones: Some initial shedding is normal, but persistent loss of stone indicates the resin layer was applied too thinly or the stone was damp.
• Delamination: The resin peeling away from the base, usually caused by applying it to a damp or dirty surface.
• Clouding/Blooming: White patches appearing in the resin, caused by moisture or rain hitting the resin before it has fully cured.

Frequently Asked Questions