I tried Wet & Forget Mould, Lichen and Algae Remover to clean my path and driveway – the results were astounding and I’ll never use a pressure washer again

Between autumn and spring every year, the encaustic tiles on my front path – particularly those beneath overhanging plants – grow a sticky, engrained lichen that absolutely refuses to budge, however hard I work at it.

This spring, though, I was sent a 5L carton of Wet & Forget Mould, Lichen & Algae Remover (which you can buy at Amazon) to try at home. It’s on Ideal Home’s list of the best patio cleaners, and I had heard it was good – but I wasn’t convinced it would remove the lichen.

After all, my Kärcher K 4 Power Control Home Pressure Washer (also available at Amazon, if you’re in the market) is rated as one of the best pressure washers, and that hasn’t been able to shift it over the years. I was quickly proved wrong – this product is not only easy to apply, it’s something of a miracle worker where pressure washers fail. The results aren’t instant, though – as I’ll explain.

How does Wet & Forget work?

You simply sweep your path – or almost any outdoor surface, including fences, roofs and even artificial grass – clean of debris, then soak it with a solution of one part Wet & Forget to five parts water to your clean, dry surface. The quickest, easiest way to apply it is with a pressure sprayer – this Spear & Jackson Pressure Sprayer at Amazon has over 24,000 five-star reviews – or, you can do what I did and mop it on.

It leaves a slightly sticky residue that has to be allowed to dry out – so don’t apply it on a day when rain is forecast any time within the next five or six hours, don’t let pets near it and try not to walk on it. I applied mine early on in the evening when I wasn’t planning on going out again.

Then, after a solid 15 minutes of fairly effortless mopping, I waited… for rain, which quickly removed the residue of the product and, over the next few days and weeks, more slowly washed away the invincible sticky lichen – you can see the before picture above and the after picture below.

Since it can take months for the lichen to regrow, I can simply just reapply a second coat in around three months to discourage any further growth. And yes, the weather is what does the trick in helping to remove the lichen, but if it doesn’t rain – I’ve given up on summer, so I’m pretty sure it will – you can mimic the effect with your hosepipe or watering can.

An added bonus? The product does not harm plants unless you spray it directly onto them, which can cause some leaf burn.

Testing Wet & Forget against other products

One of my colleagues tested Wet & Forget alongside two other patio cleaning products in the summer of 2022 – nearly two years ago to the day. She brushed it onto a section next to the other products, clearly separated by masking tape, with Wet & Forget in the middle section.

The results were obvious in a couple of weeks, but in three months, it was even more evident that the Wet & Forget worked better than the competitors. While all three had cleared most of the moss and lichen, the central section where Wet & Forget had been was definitely the cleanest – all without any scrubbing.

And, the product continues to work over time. Now, two years later, the rectangle to the right has all but returned to the colour and lichen coverage of the rest of the paving (you can only just see the outline of the section).

The left-hand rectangle is much better with only some slight marking, but the central rectangle, where Wet & Forget was used, has escaped all but the most persistent dirt.

What the reviews said

Finally, I was curious to see how other users had got on with the product so I dipped into Amazon’s reviews. Some reviewers highly recommended it not just for paths and fences but also for the exterior of their homes which were plagued with moss.

The one that chimed most with me was from a reviewer who said, ‘I’ve done the pressure spray approach before. It’s painfully slow and messy, especially if you do it properly and resand the gaps and seal the blocks.

My pressure hose deals with dirt, but struggled with the lichen. So, in short, this is vastly easier and vastly faster and vastly more effective. Just vastly slower [to see the results]. So it’s a once a year thing – do it once, takes 20 mins and never ever needs thinking about again.’