A broken window needs to be secured as quickly as possible — especially overnight — to keep out weather, insects, and intruders. The good news is that a temporary board-up is a straightforward DIY job most homeowners can handle with basic tools and materials from a hardware store. Here's how to do it safely and effectively.
Safety First: Before You Touch Anything
Broken glass is extremely dangerous. Before you start, protect yourself:
- Put on thick leather or cut-resistant gloves — standard gardening gloves are not enough.
- Wear safety glasses or goggles to protect your eyes from flying shards.
- Wear closed-toe shoes — bare feet or jandals are a serious hazard around broken glass.
- Keep children and pets well away from the area.
If the window was broken by an intruder or vandalism, check with your insurer before doing anything — some policies require you to document damage with photos first. Take photos from multiple angles before clearing glass or boarding up.
What You'll Need
You can pick up everything below at Bunnings or Mitre 10:
| Item | Notes |
|---|---|
| Plywood sheet (at least 12 mm thick) | Cut to size, or buy a pre-cut panel |
| Tape measure and pencil | To measure the opening accurately |
| Circular saw or handsaw | To cut plywood if needed |
| Drill and screws (50–65 mm) | For fixing into the window frame |
| Heavy-duty plastic sheeting or tarpaulin | Extra weatherproofing layer |
| Duct tape or weatherproof tape | To seal edges |
| Broom and dustpan | For glass clean-up |
| Thick gloves and safety glasses | Non-negotiable PPE |
If you don't have plywood on hand, a thick piece of MDF or even a solid timber offcut can work for one night, though plywood is more weather-resistant.
Step-by-Step: How to Board Up the Window
1. Clear the Broken Glass
Carefully remove any large shards still in the frame using gloved hands. Work from the outside in if possible, and tap stubborn pieces loose with a hammer handle wrapped in cloth. Sweep up all glass thoroughly — small fragments can travel further than you'd expect. Wrap glass in newspaper before placing it in the bin.
2. Measure the Opening
Measure the full width and height of the window opening, including the frame rebate (the lip the glass sits in). Add at least 50 mm on each side so your board overlaps onto solid frame or wall material — this gives you something to screw into.
3. Cut Your Plywood
Cut the plywood to your measured dimensions. If you're buying a sheet at the hardware store, many stores will cut it to size for you — just bring your measurements.
4. Add a Weatherproof Layer (Recommended)
For overnight protection against NZ's unpredictable weather, staple or tape a layer of heavy-duty plastic sheeting to the back (interior-facing side) of your plywood before fitting it. This adds a moisture barrier and helps keep draughts out.
5. Fix the Board in Place
Hold the plywood firmly over the opening so it overlaps the frame evenly on all sides. Pre-drill pilot holes to avoid splitting the timber, then drive 50–65 mm screws through the plywood and into the window frame or surrounding wall framing. Space screws roughly every 200–300 mm around the perimeter.
- If your window frame is aluminium (common in NZ homes), use self-tapping metal screws or consider using construction adhesive tape as a temporary fix instead of screws, to avoid damaging the frame.
- For a ground-floor window, consider adding a second layer of plywood or bracing for added security.
6. Seal the Edges
Run weatherproof tape or duct tape around all four edges where the board meets the wall or frame. This reduces draughts and keeps rain from getting behind the board overnight.
7. Check from the Inside
Once fitted, go inside and check for any gaps where light or air is coming through. Tape over any gaps with duct tape or stuff them with a folded cloth as a temporary measure.
Keeping Your Home Secure Overnight
A boarded ground-floor window is a visible sign of vulnerability. Consider these extra steps:
- Let a neighbour know what's happened.
- If the break-in was deliberate, contact NZ Police (105 for non-emergency) to file a report — your insurer will likely require this.
- Lock any internal doors between the boarded window and the rest of your home.
- Consider a temporary security light or alarm if you have one available.
When to Call a Professional
A temporary board-up is just that — temporary. You should contact a qualified glazier as soon as possible (most offer same-day or next-day emergency callouts) to assess the frame and fit proper replacement glass.
Call a professional immediately if:
- The window frame itself is damaged or twisted — this may affect the structural integrity of the wall.
- The broken window is a large pane, a skylight, or a high window that requires working at height — falls are a leading cause of serious injury in NZ homes. WorkSafe NZ recommends never working at height without proper equipment and training.
- The glass is double-glazed, laminated, toughened, or fire-rated — these require specialist replacement and may have implications under the NZ Building Code.
- You're unsure whether a building consent is required for the replacement (generally a like-for-like glass replacement is exempt under Schedule 1, but always confirm with your local council).
You can find qualified local glaziers on tradedirectory.co.nz to get the job done properly and safely.
Window & Glass Association
