Removing weeds from the roof? Choose the right scaffold.

For removing weeds from the roof you take the wide 135 cm RS52. The reason lies not in the height but in what has to fit on the deck: an open sack or bucket for the plant waste, a hand trowel, a gutter scraper, a tray for the loose tiles you set aside for a moment, and usually a second person. On a narrow deck you spend the day dodging all of that while twisting a clump of nettles out with both hands. The full range sits on the page for hiring mobile towers.

If you are only doing the gutter of a garden room or a low extension, the narrow RS51 at 75 cm does the job perfectly well. You make that choice the moment the route to the back is tight, because an eighty centimetre gate will not pass the wide version. Bear in mind, though, that a narrower deck sends you down more often to empty your sack, and that every trip down on this job costs a few minutes you notice again at the end of the day.

For the roof slope itself the model changes nothing about your reach. With a deck length of 245 cm you take on a good two metres of gutter and eaves per position, and that is precisely the strip where the roots sit. Climbing onto the roof is not part of it: growth higher up the slope only comes off with a roof ladder, and that is not in our hire fleet. If the weeds sit mainly up near the ridge, ask whether this equipment suits the job.

Your measuring point is the top of the gutter plus the first two or three courses of tiles above it, because that is where the roots lifting the tiles are anchored. On a house with a pitched roof over two storeys the gutter hangs around six or seven metres; over three storeys you land at eight or nine. Add the courses of tiles you still have to reach and you arrive at a working height between 8 and 12 metres, exactly the span this job belongs in.

Converting working height back into a build is easy: platform height with roughly two metres of reach on top, so the deck always sits about two metres below the point you can touch. Stand at eight metres and you get to about ten. To see which build goes with that, look at the page on ten metres of working height. Work from the level where the castors will end up: a garden falling away to a ditch easily costs you half a metre at the back.

Hiring too low takes its revenge in your back straight away. If you only just reach the gutter edge, you are groping upward with your arms extended when the whole point is to pull the roots towards you. On top of that, from a low stance you cannot see what is sitting under the first course of tiles, and that is precisely where the trouble starts. One build higher costs you a few tubes and gives you an overview of the entire run of gutter.

The tower goes under the gutter, and that is at once the place where everything you pull loose comes down. So choose ground that copes with a load of wet soil and leaf debris: slabs or block paving hose clean again, whereas a trim lawn looks different after a day. Set a wheelbarrow or a large sack beside the foot of the build, tidily outside the zone the stabilisers occupy, so that you do not have to drag it clear at every move.

Look carefully at what is drawn up under that gutter line. Older houses tend to have a border of perennials along the back wall, a water butt under the outlet or a gravel strip choked with leaves. Together those decide whether you can get all four stabilisers down, and finding that out now beats discovering it with the components already lying on the pavement. For a sloping rear path or settled paving, the approach is described in the article on a mobile tower on unequal ground.

Keep the strip directly under your work clear of people and belongings. What comes out of the gutter is heavy, wet and sometimes mixed with shards from a cracked tile, and it lands with a thump. If the wall borders a shared path or the pavement, tape that section off for as long as you are up on the tower. Warning the neighbours also saves an argument about the muddy patch that inevitably lies there after a day of work.

Per position of 245 cm you are soon half an hour to an hour busy where the growth is well established. An average house has eight to twelve metres of gutter per side, so count on four or five positions per elevation plus the shifting in between. Do two sides of the house and you are still not empty handed at the end of the second day. Removing weeds from the roof therefore runs to two or three rental days, and a long rear elevation with heavy growth deserves one more on top.

The weather steers that plan more than you would like. After a few wet days the roots come away a good deal more willingly, but the platform is then also slick with dragged in leaves. In a frost the contents of the gutter sit solid as a block and you make no progress at all. A dry spell after rain is therefore ideal, and you can see that coming a few days ahead at best. So reserve with a day in hand rather than trimming your booking to the bone.

Booking that generously costs you almost nothing. Only the opening day is charged in full, and ninety five per cent comes off every day you hang on the end of it. Two extra days for a disappointing rear elevation is then no longer a money question but a planning one, and it spares you the rushed work in which roots stay half in place. What the rental price per build and per model comes to is set out clearly on the page with the tariffs.

Work each position from the top down and from left to right, so that you never cross the same stretch twice. Begin at the tiles: lift the bottom course carefully, follow the root to the seam and pull the clump loose in one piece. Leave part of a root behind and the grass is simply standing there again next spring. Lay tiles that come free on the deck of the tower and not on the roof slope, because a tile sliding ten metres takes the gutter with it on the way.

After that comes the gutter itself. Scoop the layer of leaf litter into a sack by hand instead of sweeping it over the edge, and only rinse the channel once all the coarse material is out; otherwise you flush the remains into the rainwater pipe and gain yourself a blockage. Lower full sacks on a rope rather than carrying them down the build under your arm, since a wet sack of soil and roots weighs more than you judge from up top.

The difference from the jobs that resemble this one lies in the roots. A layer of moss you brush off the roof slope, and that calls for a different arrangement; how that goes is covered under taking moss off a roof. If it is purely leaf litter and silt in the channel, your job belongs rather with cleaning out the gutter. Removing weeds from the roof sits between the two: slower per metre, and higher than the gutter alone.

What comes out of the van is a counted set of separate components and not a ready made tower. Find a spot in advance where that pile may lie for a few days without blocking your wheelbarrow and your full sacks. The drive is usually handier than the back path, because you can get a trailer or a skip alongside it there. Orders logged with us on a working day ahead of 15:00 are loaded and driven to the agreed address the working day after.

When we bring it and when we take it away again is something you set in the reservation yourself. On this job you look at the forecast first: have the components arrive on the last wet day, so that you can use the dry days afterwards in full. Stacking is your part of the work: you go through the manual with the instruction film beside you, and for ten metres you need two people and roughly an hour. So do not start building late in the afternoon.

Once the gutter is empty you dismantle the tower and stack the components back where they were unloaded. Hose them off first, because gutter silt and soil dry on the tubes into a crust that hardly shifts later. We then take the lot away again on the day you selected. Clear the plant waste before the van turns up, or the driver ends up loading from between your full sacks and the job takes twice as long.

Each square metre of decking will take 200 kg, a ceiling that belongs to load class 3 and is written into the EN 1004 standard. On this job you creep closer to it than you would expect: wet soil, moss and roots are heavy, and two full sacks plus two people plus tools mount up smartly. So do not stand full sacks side by side in one corner but spread them over the length of the deck, and lower them as soon as they are full instead of collecting them up there.

The biggest hazard on this work is the platform itself. Wet leaves, mud and moss turn a deck greasy inside an hour, so sweep it regularly and never let a layer of waste build up. The other agreements are the familiar ones. Put the brakes on before climbing, keep people and material off the build while it is wheeled along, and stop once the wind gets up. Wind bites extra here, because dry plant waste flies everywhere and lands unasked in the neighbours' garden.

Finally, think about what can fall off your deck. A hand trowel, a tile or a half full sack arrives below at real speed, and you are often standing above a path or a terrace. Keep that zone empty and lay tools in a tray rather than on the edge. The remainder of what applies sits in the article covering the rules that govern work at height, and on a job like this one that is not superfluous reading at all.