L C McCarthy

How the Snow Foam Lance brought harmony back to my roof

Iv’e been waging war on the moss growing on my roof tiles for a long as I can remember. Clambering up and down ladders, lugging washers and sprayers all over my roof, scrubbing, scraping, and swearing quite a lot.

Up here in Scotland there’s much dullness on show, and the weather can also be quite drab. The cool damp, virtually sun free days make for a delightful paradise that moss really enjoys. What with the constant breeze and the active bird population the spread of spores is on full power all year round. Moss is highly active during Autumn into Winter. With the warm winters and poor summers it might seem like the seasons don’t matter. Moss is quite content at very low, including freezing, temperatures. The summer last year did very little to kill it off. You’d think that those two weeks in early August would have some impact but sadly it did not… Didn’t do much for me either.

For those not in the know you really cannot ignore moss. Perhaps if you move every couple of years you may avoid treating/dealing with it. Unless you buy the house off someone who had the same idea as you. Damn!

Moss will remove the protective coating of your concrete tiles. Frost can then penetrate, cracking or eroding the tile and allowing the weather in. It will get under any type of tiles and slates and again let the weather in, along with all the pests you can imagine. Leaking rooves/roofs and rotting timber all round. It will clog waterways and water damage will ensue. Result – expensive repairs and an uncomfortable existence.

Okay, so it needs to go. I’ve used allsorts in my campaign against the green plague. The best for me is Patio Magic. It’s not just restricted to the Patio. It’s so effective against anything green that even enviromentalists won’t come near the house. You can decide if that’s a positive. However, I’ve really struggled to find a really good way to apply it.

Spraying with the standard garden 8l pump outfit is okay at lower levels but cumbersome with patchy results working off a ladder. I’m not health and safety obsessed but I don’t like falling off a ladder. It tends toward the inconvenient. It was difficult to get into all corners and any wind, even the slightest of breezes, would make the task unfeasible, or distasteful with a faceful of chemical.

I’ve used a power washer to remove the moss previously but I stopped quite a while ago. I found that the washer itself was causing damage to the tiles, almost as much as the moss I was removing.

One day a few months back I had a brainwave. Combine the two together. Apply the patio magic with the power washer. I hadn’t seen it done elsewhere but it sounded feasible. I’d been using a snow (foam) lance on the familys’ cars for years. It had good coverage and flew a good distance without excessive force.

I mixed up a 50/50 mix of the product with tap water and filled a one litre bottle. First time out with no tweaking, adjusting liquid or working out a specific strategy, it produced a perfect result. It foamed straightaway, which I wasn’t expecting, covering the tiles completely with a nice thick white blanket. After a short while it ran down the roof ensuring all the moss and algae ended up well coated. The foam dispersed after 5-10 minutes but the roof stayed wet. This is always going to be dependant on weather conditions but still a great result. The picture below centre has around 250ml – a quarter of the bottle – covering the area. The entire roof shown would use the whole 1lt.

The image above shows the lance with nozzle open. Without moving the lance it’s reaching 5.5 metres. Using your reach and the gun, plus extensions, 8 metres is easily achieveable. The major plus is the product is not being blown about and dispersed due to the power charactersitics of the lance. There was a 10 mph breeze from behind the operator, at about 11 o’clock – direction not time. As this roof is just under 5 metres from ridge to gutter it’s not required to actually get onto the roof . That’s been done for visual purposes. For the same reason the roof is moss free having been treated previously. It was judged the best roof for ‘show’ purposes – by me not some weird competition.

The centre picture shows the lance set to wide spray and it’s clear to see the change in pattern of application. Bottom right gives an idea of how the mix is going on. Looks pretty good bearing in mind it’s not a soap, or even identified as a foaming product.

Bottom left shows roof after around 7 minutes. The foam has gone and it’s starting to dry. However, the chemicals are still present and any moss will still be soaking.

Equipment

I’ve used the following equipment but this method will work with anything capable, of your choice.

• Karcher K4 130Bar
• Nilfisk C120.7
• Nilfisk C110.3
• Both branded (as above) and 1/4″ quick release fittings and accessories. A gun hose extension – widely available – is needed unless you live in a Munchkin house.

Snow Foam Lances

I’ve used a couple of different Foam Lances with this stuff. All have worked fine. If you’ve never had one before for the money you can’t go wrong. The middle one I bought 4 months ago for £13/$15. The nozzle twists to change the pattern as shown above, and the knob on top adjusts the water flow coming from the washer – as described below. The inset info should enable you to identify similar products in your locale.

Capability and Effectiveness

What can you expect in the way of coverage? This seems to be a really economical use of this product: far better than the stated coverage on the label. My lance is always set to combine the mix with water coming through the washer. If you close down the knob on top of the lance you’ll just get pure mix and it won’t travel as far or last. Opening it a little and adjusting for consumption and distance is trial and error, and unfortunately as all lances will be slightly different I can’t give exact figures. Suffice to say go easy, it only takes a couple of minutes to find the sweet spot, and minimal mix will be lost, and that’ll be onto the unwelcome moss – so all good. The label says 85m2 coverage for 2.5lt. My method gives more like 2 1/2 times that (see 2 images above). The other label info stands e.g ‘Don’t apply with rain due’ etc..

Sounds very economical. I paid £9 for this product. But is it effective? You know it’s going to be or we’d all be looking elsewhere now, right? It behaved exactly the same as when i’ve sprayed it before on fences, walls and some tiles – the ones i could reach. The bright green algae went fast. Some within an hour. Practically all within 48hrs. The moss changed colour to dark reddish brown over the course of a week. It’s dead. It will detach and come away from your tiles, however a small percentage will retain a death grip. You can remove it or leave it, it can’t cause any trouble unless it’s wedgeing a tile up or pushing a fascia out etc.. I would recommend putting some plastic garden mesh in your down pipes or even temporarily taking the gutters down if you have a lot of moss. Blocked by dead moss, drainage is even less amusing than a mossy roof. Either way be prepared to de-moss. Probably not a word but it works.

I think the result is great. It’s an excellent method. Not only does it cover well and efficently, it’s also very fast to apply. What’s shown above is around half of the total roof area. It was all treated in around two and a half hours. That includes the time taken to move and position all the ladders, power washer, water and power feeds four times. I can’t do all four sides of the house at once – it’s not real magic.