Removing graffiti? Choose the right scaffold.

On a wall that gives straight onto the street the Altrex RS51 is the practical choice, because at 75 cm across the build still leaves a strip of pavement for people who have to get past. A wider build in a town centre soon means blocking the whole footway, and then you are into barriers, permits and irritated neighbours. On the street the slim version therefore wins nearly every time; how the other models compare is shown at our mobile scaffold hire.

Less has to go up on the deck than you would expect. If you work with a remover, a tin or tub of gel goes up along with brushes, a scrubbing brush, cloths and a spray bottle of water. If you work with light blasting, the machine stays on the ground and you have only the lance and the hose in your hands. Either way what you want is freedom of movement along the tag, and that comes from the deck length of 245 cm rather than from extra width.

The wide RS52 at 135 cm is rarely needed here and often a nuisance. It asks for more pavement, more parts to unload and more time to shift, exactly what you can do without on an urgent job. Only when two people work one large area at once, or when heavy equipment has to stand on the deck, does that extra room outweigh the bother. If you are unsure, look at the overview of scaffold sizes.

Tags seldom stay at eye level. Anyone who has stood on a roof or a bin reaches five metres easily, and on a blank side wall a piece sometimes carries on above the first floor. So measure to the highest spatter of paint you still want gone and not to the middle of the letters. Land on four to six metres and the build to book is one of 6 to 8 metres working height. What that comes to in sections is set out on the page for six metres of working height.

The arithmetic behind it is simple. Your boards plus another two metres or so of reach give the working height that goes into the booking. If you stand on a pavement that slopes, or on a raised kerb, that starting point shifts and so does your whole build. Look too at whether a canopy, an advertising board or a shopfront is in the way, because you have to work round it and that often costs you half a metre more.

Starting too low is more of a nuisance with graffiti than with other wall work. You have to scrub with real force or hold a lance at a distance, and neither goes well on tiptoe. On top of that you want to work well past the last letter along the top, because a hard border between treated and untreated brickwork stands out just as much as the tag did. For a wall up to the first floor you would rather be slightly over than under.

The standing place on this job is rarely a quiet back garden. You are on the street side, on a pavement with cyclists alongside and passers by who simply want to get through. Measure that pavement before you reserve: the 75 cm build plus the spread of the four stabilisers has to fit on it, and a walking lane has to remain. If nothing is left over, you divert people on foot and report it to the council beforehand, because that is not arranged on the morning itself.

Then look at what goes on beneath you. A parked car within splashing distance, a shopfront with a display outside, a cellar light or a gully where rinse water with residue in it disappears: they all sit exactly where you want to work. Lay sheeting or film to catch blasting grit and rinse water, and place the build so your stabilisers do not land on a manhole cover or a loose paving slab. For sloping or uneven paving, the explanation of ground and level differences helps.

An audience comes with this work. People stop to watch, children walk under the build and somebody always wants to ask what you are doing. So fence the zone round the base with tape or barriers, even if you are only busy for an hour. That not only prevents accidents, it also stops somebody cycling into a standard while you are five metres up with a lance in your hands and no way to catch it.

One tag on a blank wall is usually half a day of work, but you seldom hire that short. You start with a trial patch somewhere inconspicuous to see how the substrate reacts, and that has to soak and dry before you can judge the result. Only then do you know whether one treatment will do. For an average case on a wall along the street you therefore end up on one to two hire days, and on a large area more.

There are waits in it you cannot hurry along. A gel has to draw in, a treated area has to dry before you see what has really gone, and on cold or wet days almost every product works more slowly. Blasting has its own pace as well, since you go over lightly and repeat rather than going too deep at once and opening up the brickwork. So you build that second round into your hire period, along with half an hour of clearing up.

Better, then, to reserve a day on the roomy side. After the first twenty four hours, which count at the normal rate, every further hire day costs only a fraction: 95 per cent comes off it. That leaves you slack for a second treatment or for a wet morning, without ordering again, having it delivered again and building again on a pavement you had only just cleared. Rules of thumb per type of job are in this piece on how long to hire.

A tag is often wider than the 245 cm you have in front of you per position. That is more awkward than it sounds, because you would rather treat one area in a single continuous movement. Stop halfway and pick it up again after a move, and the soak time of the first part runs ahead of the second, which you see back later in the colour of the brickwork. So divide the work into strips you finish completely from one position.

Take up in one go what belongs to that strip. With a remover that means the gel, a brush, a scrubber, cloths and water; with blasting only the lance, the hose hanging in a generous loop along the guard rail down to the machine. Never let that hose run tight between the wall and the build, and do not lay it under a castor, because you will pull it off as you move. Switch the machine off below before you climb down.

What people misjudge is the edge zone. A cleaned area on an otherwise dirty wall shows up as a light patch, so in practice you work a larger surface than the letters alone. That means more positions than you had counted on and so a longer hire period. If you are going to tackle the whole wall, plan it as a clean of the facade rather than as taking a tag off, because that is another sort of job with another hire period.

With graffiti you generally want to have started yesterday, and the lead time is arranged for that. For urgent work 15:00 is the hinge: reservations settled before then on a working day are delivered the next working day. Which day the van comes and when it takes the set away again is yours to decide, so you have it arrive when the street is at its quietest. What else is possible in a hurry is set out in the piece on hiring a scaffold at short notice.

You receive a complete, counted set of loose parts. On a pavement there is little room to drop that stack, so agree beforehand where the van may unload and lay the parts against the wall instead of in the middle of the path. Building is your task: you do that with the manual and the instruction film, and on the street it goes faster with two people who take turns keeping an eye on the traffic.

As soon as the wall is clean you strike the build and we come for the parts. Rinse the blasting grit and the product residue off the tubes and the deck first, because that stuff creeps in everywhere. Stack it all somewhere the van can stop alongside without trouble, preferably not where loading is banned. Bringing and fetching carry a fixed amount per province including VAT; the rate for your address is shown with the delivery rates.

Underfoot you have a deck good for 200 kg per square metre, the figure that load class 3 of EN 1004 stands for. On graffiti you do not get near it soon, because you work with light gear; the weight sits lower down, in the blasting machine and the bag of granulate. If you are up there with two of you on one deck section with buckets of water as well, count it through before you begin. More about that grading is in the note on the load classes.

On the street the ordinary rules apply with extra force. Lock all four castors before you climb up, never shift the build with a person or equipment on it, and stop when it blows hard. On a sloping pavement you check that again after every move. Wind is a double problem here: it pushes at the build and at the same time carries the mist of your product or the fine grit right across the road, where cars and shop windows stand.

The real risk on this job passes below you. People walk by who do not look up, and everything you drop lands on the pavement. So work behind a cordon, hang a sheet under your working area if you are using grit, and keep chemical product away from playing children and dogs. Wear gloves and goggles yourself, even if you are only at it a short while. The remaining rules are under safe work at height.