In many cases, yes — resealing the edge of a lifted glass splashback is a manageable DIY job, provided the glass itself is intact, properly supported, and not installed near a gas cooktop. The key is using the correct sealant, preparing the surface thoroughly, and knowing when the job is better left to a professional glazier.
Why Does Splashback Sealant Lift?
Glass splashbacks are typically held in place with a combination of neutral-cure silicone sealant around the edges and, in some installations, a structural adhesive or mechanical fixings behind the panel. Over time, sealant can lift or peel away due to:
- Heat cycling — especially behind a rangehood or near a cooktop, where repeated expansion and contraction breaks the silicone bond
- Moisture ingress — steam and water work their way under the edge, causing the sealant to delaminate
- Poor original installation — using the wrong type of silicone (such as an acetoxy-cure product, which smells strongly of vinegar) on certain substrates
- Surface movement — minor settlement or flexing of the wall behind
A small lifted section at the edge is usually a sealant failure, not a structural problem. However, if the entire panel feels loose or is bowing away from the wall, stop and call a glazier — a falling glass panel is a serious safety hazard.
Safety First
Before you start, check a few important things:
- Is the glass toughened (tempered)? Splashbacks should always be toughened safety glass. If you're unsure, look for an etched or printed mark on a corner of the glass. Do not attempt any work on a panel you suspect is standard float glass — contact a glazier immediately.
- Is it near a gas cooktop? If the splashback sits directly behind a gas hob, there may be clearance and compliance requirements under the NZ Building Code (in particular, Clause G11 relating to gas as an energy source — though you should confirm the specific applicable clauses with a licensed gasfitter). Have a licensed gasfitter or glazier confirm the installation is compliant before you disturb the sealant. You can find licensed gasfitters through the Plumbers Gasfitters & Drainlayers Board.
- Is the panel fully supported? Gently press the glass — it should feel solid against the wall. If it flexes or rattles, the adhesive behind may have failed and resealing the edge alone won't fix it.
What You'll Need
- Neutral-cure silicone sealant rated for kitchens and bathrooms (mould-resistant). Brands such as Sika offer suitable products widely available at Bunnings or Mitre 10. Avoid acetoxy-cure (acid-cure) silicone on glass-to-tile or glass-to-painted-surface joints — it can cause adhesion failure and staining.
- Silicone remover or a plastic scraper
- Methylated spirits or isopropyl alcohol (for cleaning)
- Masking tape
- A caulking gun
- A silicone finishing tool or a wetted finger
Step-by-Step: Resealing the Edge
1. Remove the Old Sealant
Use a plastic scraper or a silicone removal tool to carefully cut away and peel off all the old sealant. Take your time — leaving old sealant behind is the most common reason a new seal fails quickly. A silicone remover product can help soften stubborn residue.
2. Clean the Surfaces Thoroughly
Wipe down both the glass edge and the adjacent wall or benchtop surface with methylated spirits or isopropyl alcohol. Allow it to dry completely. Any grease, soap residue, or moisture will prevent the new silicone from bonding properly.
3. Mask Up
Apply masking tape along both sides of the joint — on the glass and on the wall or benchtop — leaving a neat, consistent gap. This gives you clean, professional-looking lines.
4. Apply the Silicone
Load your neutral-cure silicone into the caulking gun. Apply a smooth, continuous bead along the joint, slightly overfilling the gap. Work in one direction without stopping if you can.
5. Tool and Finish
Smooth the bead with a wetted finger or a silicone tool, pressing it firmly into the joint. Remove the masking tape immediately, before the silicone skins over.
6. Cure Time
Leave the silicone to cure fully — typically 24 hours minimum before exposing it to moisture, and check the product datasheet for full cure time before using the cooktop nearby. Sika and other manufacturers publish technical datasheets with specific guidance.
Choosing the Right Silicone
| Situation | Recommended Type |
|---|---|
| Glass to painted plaster wall | Neutral-cure, paintable silicone |
| Glass to tile | Neutral-cure, mould-resistant |
| Glass to benchtop (stone/laminate) | Neutral-cure, kitchen-grade |
| Near cooktop (high heat) | Check manufacturer's temperature rating |
Always read the product datasheet and confirm it's suitable for your specific substrate. BRANZ provides useful guidance on sealant selection and building envelope performance.
When to Call a Professional
Call a qualified glazier if:
- The glass panel feels loose, bows, or moves when pressed
- The glass is cracked, chipped, or you're unsure whether it's toughened safety glass
- The splashback is directly behind a gas cooktop and you're unsure about compliance
- The lifted area is large or the sealant has failed all the way around the panel
- You're a landlord — under the Healthy Homes Standards, kitchens must be maintained in good condition, and a properly sealed splashback is part of that
A professional glazier will also be able to advise whether the panel needs to be removed and re-adhered, or whether a reseal is sufficient. You can find qualified local glaziers on tradedirectory.co.nz.
Window & Glass Association
