Cleaning a facade? Choose the right scaffold.

The Altrex RS52 is the wide one in the fleet at 135 cm, and in its heaviest build the model reaches 14.2 metres of working height; for a deep clean over two storeys you pick a build of 5.2 to 9.2 metres out of that range. On wet work you need that width badly. A can of product stands on the deck, a bucket of clean water, a low pressure sprayer and one or two brushes on poles, and you do not want to be shuffling between the lot of them.

There is a second reason. The moment you start rinsing, part of the deck goes wet and slick, and then it helps to keep a dry strip to stand on and to set your things down on. On a deck 245 cm long and 135 cm across that works; on a narrow one everything sits in the same puddle. Working as a pair, with one applying and the other rinsing behind, the wide build is the obvious choice.

The slim RS51 at 75 cm stays usable for the back of a terraced house, where the only way in is a gate or a narrow path. Reckon then on climbing down more often to fetch something, on leaving your can at ground level and on moving more carefully across a wet deck. For a street elevation that is rarely necessary. Both versions are described alongside each other on the mobile scaffolds we hire out.

A clean rarely stops halfway. Green growth and grime sit precisely under the roof edge, along the gutter and on the north side, so your highest point is nearly always the top of the brickwork. From the deck you stand on, a brush on a pole takes you another two metres or so, and that is the margin you count with. On a wall that finishes at a good seven metres you land on a build of around 9.2 metres.

You start measuring on the paving where the wheels will go, and on this job that is by no means always level with the front door. Cleaning often begins low at the plinth, where most of the growth is, and that plinth sometimes sits half a metre below the terrace. Carry that difference into the figure you book, or you fall short at the top by exactly that half metre. The build to match sits on the page about nine metres of working height.

Pick too low and a band is left at the top that leaps out once everything has dried. A cleaned facade with a dirty stripe under the gutter draws more attention than a wall you never touched. Rinse water from that dirty section also runs down over your finished work, so the bottom starts again. In doubt over a facade of two storeys, simply sit one build higher and hire the extra metre with it.

Everything you put on the wall ends up below in the end. Expect the strip a metre wide along the brickwork to be soaked through by the time you finish, and that is exactly the strip your wheels and your stabilisers are standing in. On blocks or slabs that is no trouble. On a lawn, a border or a path of bark chippings the same strip turns to mud within a day, and then a wheel sinks while you are up top.

Lay road plates, paving slabs or stout boards under every foot before you start, even if the ground looks hard on arrival. Look as well at where the water can go: a gully in the drive, a gravel margin or an outlet in the terrace. One bucket is nothing, but a day of rinsing produces hundreds of litres. If it all runs towards the cellar window or the neighbours' crawl space, move your starting point. Keeping a tower steady on such ground is covered in the explanation about stabilising.

Clear the zone under the build out properly as well. Garden furniture, bicycles and pots catch not only water during a facade clean but traces of product too, and planting right against the wall suffers from that. Cover them or move them away, and warn the neighbours if your walls butt up against theirs. That is a matter of thinking a day ahead before the mobile scaffold is delivered, and it saves you an afternoon of cleaning up afterwards.

On a deep clean the soaking time sets the pace, not your arms. You put the product on bay by bay, wait out the period the label asks for and rinse afterwards. During that wait you can at most prepare a second bay, but you cannot move, because a half soaked bay is not something you walk away from. On one elevation of two storeys that adds up to two to four rental days, even though the work itself looks like little.

Then comes the drying. Only once the wall is genuinely dry do you see whether the result is even everywhere and whether a bay needs a second treatment. That judgement cannot be made the same afternoon, so keep a day in hand on which you can still touch things up. You also do not want to apply product with rain on the way, because it washes off before it has done anything and that bay starts again.

The way the tariff is built works in your favour here. You settle the first twenty four hours at the full rate, and every rental day after that has ninety five per cent taken off, so an extra drying day costs you next to nothing. That is precisely the slack a deep clean needs. Book a day too many rather than stand rinsing while the van is already on its way. A realistic estimate comes from the overview of rental days needed.

One set up with a deck of 245 cm covers a bay of wall a good two metres wide, and that bay is your working unit. Put the product on from the bottom upwards, so you avoid dry bands where it runs down over a wet streak. Rinse afterwards the other way round, from the top down, in calm overlapping passes. Only move the build once the bay has been rinsed through and the water has run out of it.

High pressure you leave alone. A hard jet drives water through the joints into the wall, blows soft pointing and render apart and chases dirt rather than dissolving it. On a mobile scaffold something else comes with it: a lance under pressure pushes back hard, and you brace that force against a build standing on wheels. Work therefore at low pressure, with a generous flow of water and a brush for the spots that resist.

What people underrate is how often this job sends them down. Refilling a can, fetching a different brush head, shifting the hose: on wet work that happens more than you planned for, and with wet hands on a wet rung you want to limit those climbs. Take everything up in one go per set up and keep a spare bottle ready. If you go on to seal the facade later, you use the same division into bays.

What turns up is a stack of loose parts, counted out and complete. Point out a dry spot for that stack, far enough from the wall that no rinse water will run over it and with room to walk past carrying a full bucket. A drive or a piece of terrace works better than the grass you are going to soak later anyway. Whoever books on a working day and beats the 15:00 mark gets the parts on the next working day.

You fill in the delivery day and the return day yourself, and for cleaning you look at the rainfall forecast to do it. A dry spell of a few days is worth more than an early start date, because rain during the soaking time makes your product useless. Have the set arrive the day before your first cleaning day, so the build already stands before the first bay comes up. Allow half a day for that, and do not start on a wall the morning the van pulls in.

Once the job is done we come and fetch the build again, as soon as you have taken it apart and laid it complete on the drop off spot. Rinse the tubes and the decks with clean water first, because traces of cleaning product have no business drying on the material. Let the lot drain before you stack it. The amount for the outward and return trip differs per province and sits with the fixed rates for delivery.

Each square metre of deck under your feet may carry 200 kg, which is load class 3 within EN 1004. On a clean you rarely get near it, unless you work as a pair and full cans and buckets of water stand there too; water weighs more than people reckon. Spread the load along the length of the deck rather than heaping it into one corner. Where that upper limit comes from is spelled out in the explainer on the mobile scaffold standard.

The real hazard here is right under your soles. A deck carrying water and a soapy product turns treacherous, certainly at the spot where you keep turning to reach the bucket. Wear footwear that keeps its grip, wipe the deck dry between passes and put nothing down that you have to step over. Keep the brakes on while you are up there and never shift the build with a person or with material aboard. Walk the stabilisers round again after each move.

Below the build wet jobs also ask for care. Rinse water runs down, a hose lies about and there is often an extension lead running to a small pump. Keep electrics high and dry, let nobody walk under you while you rinse, and stop when it blows, because then the product drifts as a mist across the garden. Agree who keeps an eye on the hose from below, so it never pulls tight between a wheel and the wall. The further rules sit at working safely at height.