FlarnexClearing weeds from paving without a spray
Heat will clear the gaps in a path or a patio without any chemicals. It is not a one-off job, though, and it will not shift everything. Here is what to expect.
10 September 2026
How heat kills a weed
You do not need to burn a weed to ash. A few seconds of intense heat is enough to burst the cells in the leaves. The plant wilts and dies back over the next day or two, even though it may look almost untouched straight after.
That is the most common mistake: people keep heating a weed until it is blackened, which wastes time and power. Pass over it, move on, and come back to check a couple of days later.
Why it suits paving so well
The gaps between slabs are narrow and hard to reach with a hoe. They are also exactly where you would least want a chemical weedkiller, which can run off into drains or onto the lawn. Heat treats only what you point it at and leaves nothing behind.
How often to go back
Young weeds with shallow roots usually die after one treatment. Tougher, deep-rooted weeds grow back from the root, so you need to treat the new growth each time it appears. Every time you do, the root has to spend energy regrowing leaves, and after several rounds most give up.
| Type of weed | What to expect |
|---|---|
| Young seedlings | Usually gone after one pass |
| Moss and small annual weeds | One or two treatments a season |
| Dandelions and other deep roots | Repeat each time new leaves appear |
| Established brambles and woody plants | Heat alone will not do it — dig them out |
Using an electric weed burner
Our EcoFlame burner runs at 2000 W and reaches around 650 °C, with no gas bottle and no open flame. It plugs into the mains, so you will need an outdoor extension cable long enough to reach the far end of the path. At just over a kilogram it is easy to hold for a long session.
It has a second use, too: with the supplied attachment it lights a charcoal barbecue in a few minutes, without lighter fluid.
Staying safe
- Never use it on a dry, windy day near dry grass, hedges or fences that could catch
- Keep it well away from wooden decking, sheds, plastic and garden furniture
- Wear closed shoes and keep children and pets clear while you work
- Let the nozzle cool completely before putting it down or away
- Treat it as a heat tool, not a toy — the tip stays hot after you switch off
Heat is not a cure for everything. If a path is overrun with established brambles or ivy, dig them out first, then use heat to keep the gaps clear afterwards. It is a maintenance tool, not a clearance tool.
When to do it
A dry, still day is best, and early in the season is better than late. Catch weeds while they are small and they will die in one pass. Leave them until midsummer and you are into repeat treatments.
Questions about the burner or about a particular weed? Email support@flarnex.com — a photo of the problem helps us give you a useful answer.