Cleaning plasterwork? Choose the right scaffold.

With a rendered elevation over two storeys the model to hire is the Altrex RS51, which builds up 75 cm wide. Very little travels up with you: a brush on a pole, a hose running at low pressure, a sprayer of cleaner and a cloth over your shoulder. A broad deck does nothing for that load, while the slim width slips past a fence, through a side gate or along the alley between two houses. The other widths sitting in the mobile scaffold hire range are set out there with their reaches.

On this job the 245 cm platform length counts for more than the width of your deck. You work panel by panel, wetting the render, laying the product on, letting it draw, brushing gently and then rinsing off, and you want that panel as large as you can keep it so there are fewer moves. Each shift of the tower also hands you a moment where the edge of the previous panel has begun to dry, and it is exactly on such a joint that render keeps a pale line you will see later.

The wider RS52 at 135 cm only earns its keep if two of you stand at the same panel, or if repair material goes aloft because patching follows the wash. For a one person clean, that extra floor mostly buys you carrying work through the garden and a tower that no longer fits between anything. Both widths sit beside one another in the table of tower dimensions if you want to compare footprints before the booking goes in, and the reach column there tells you at a glance which build heights either width will cover.

Measure to where the dirt comes from rather than to the top of the stain. A black streak starts at a leaking gutter joint or an overflow, and green growth often stops precisely where the roof edge throws the water clear. To get a brush up there on a two storey elevation the build wants 6 to 8 metres of working height. What such a build consists of is explained at an eight metre working height, along with the components involved.

Your deck then hangs somewhere between four and six metres, since the working height quoted is simply your deck height with two more metres allowed for arms and brush, and a pole on the wash brush stretches that further still. Take the measurement from the spot the castors will actually rest on rather than from your terrace, because a garden falling away towards the boundary can swallow half a metre of your sum. Guidance for a build serving the first floor of a house sets out the heights people usually settle on.

Reserve a build that is too short and the source of the fouling stays out of range, which puts you back on the same spot hiring again in half a year. You will wipe the streak away, but the dirt returns down the identical track because nothing changed above it. On top of that the top band has to be worked with arms at full stretch, so the brush presses unevenly and leaves render with a lighter band that only shows once everything has dried out.

Everything you put onto the render above drains without fail to the foot of the build, and that is where the castors rest and the base of the tower is braced down. So look hard at what that strip will take. Block paving and concrete keep bearing after hours of wet work, but a border or a lawn edge saturates and starts to give the moment you rinse over it for half a day. Lay wide boards under the base plates there and walk round after each round to check nothing has settled.

Think about where the rinse water goes as well. Cleaning plasterwork means using a product, and you do not want that vanishing unfiltered into a neighbouring border or a pond. Fix the drainage route in advance, sheet up anything sensitive that is planted, and save the lowest part of the wall until the very end. For a garden that does not lie flat, the piece on uneven ground under a tower gives you the order to level in.

The surroundings weigh on the choice too. A rendered elevation often faces the street or a narrow side garden, with an outside tap, a bike rack or a shed exactly in the way. Clear all of it before the hired scaffold turns up, because shunting between obstacles ends up costing more time than the wash itself. If part of the tower lands on the pavement, leave a walking route open alongside and warn the neighbours about flying spray. Cleaning plasterwork throws a fine mist a good deal further sideways than you expect.

Washing goes slower than painting, because the product needs its time and you have to wait on it. Per panel you wet the render, lay the cleaner on, leave it to draw and only then brush softly and rinse. Those pauses cannot be made up by working harder, and they set how many stands you finish in a day. Across two storeys that works out in practice at two or three days on hire, depending on how thick the growth has gone. Cleaning plasterwork is measured in days on hire rather than in working hours.

Allow for a second round as well. On the shaded side and behind planting a haze frequently survives the first treatment and only becomes obvious once the panel is bone dry, and render dries slower than brick. You want the tower still standing on the day you judge the result. Strike it too early and you are erecting again for those last panels, a full working day behind where you meant to be. Renting the tower over the drying night is the cheaper half of that choice.

An extra date barely shows on the rental price. Only the first day carries the whole rate, and each date you tack on behind it is discounted by 95 per cent. Booking generously is therefore close to free, while booking tight buys you a whole second assembly. Put the collection date after the day you assess the cleaned wall. To pin that span down more sharply, a breakdown of typical hire lengths takes it further.

Per stand you take a bay of a good two metres across, over the full height you can reach from that position. Always begin by wetting the wall, because dry render drinks your product straight up and then works unevenly. Lay the cleaner on from the bottom upwards after that, so no dry bands are left for it to run across and streak. Rinsing runs the other way, from the top down, once the dwell time has passed and the growth is letting go.

Brush gently and with judgement. A rendered wall carries a grain or a texture, and a stiff brush or heavy pressure takes it off; what is left is a smooth patch that will always look different from the rest of the panel. Use a soft wash brush on a long pole, let the product do the heavy lifting, and hold the same stroke across the whole face, including the places where the growth clearly sits thicker. Even pressure over a whole panel is worth more here than speed.

Watch the pattern itself while you work, because it tells you where the tower has to stand next. A narrow streak fanning down from one point comes out of a leak, a broad grey band above the plinth is splash back, and a rust trail comes off an anchor or a bracket. Note what you see from your stand, ideally with a height beside it. If it starts at the gutter, a clean out of the roof gutter fits into the same hire period.

What arrives is a counted package of tubes, deck boards, braces and guardrails; assembled delivery is something we never do. Decide well ahead where that package may be set down and pick a spot that stays dry, because the strip along your wall is about to be soaking for days. A drive or a terrace on the far side of the garden serves perfectly well, even over a longer period. A reservation confirmed by 15:00 goes out with the next working day run, so the parts are there in the morning.

The delivery morning and the pick up day are yours to name, and for washing work you name them by the forecast. A lightly clouded day is ideal: bright sun dries your product away before it has drawn and a downpour rinses it off unused. Have the parts come at the start of a settled spell. Building it is your side of the hire agreement, with the manual and an instruction film covering the order of the components. No tower ever leaves our depot assembled, so allow build time inside the days you book.

After the last rinse you take the tower apart and we bring it back to the depot on the end date you chose, with everything stacked complete and counted back onto the list. Prefer to fetch the set by car and collection costs nothing by appointment at Zeeburgerpad 89, 1019 AD Amsterdam, provided the longest parts fit your trailer or roof bars. What running out and back within your province comes to, with VAT included, appears at the fixed carriage charges per province.

Under EN 1004 a deck of this kind falls in load class 3, signed off for 200 kg on every square metre. On a wash down you come nowhere near that ceiling, because little beyond a brush, a hose and a jerry can goes aloft. What does go up is water, and that changes the floor under your boots. A wet deck board with a film of loosened algae on it is glassy, even when it looks harmless from the ground. Cleaning plasterwork keeps you under the load limit and squarely on the slip risk.

So put non slip matting or a rough mat where you stand longest and wipe your soles regularly. Brake the castors as you step on, never roll a metre with material or a person aboard, and stop rinsing once it genuinely starts to blow, because the mist of product then goes everywhere at once. Walk the four stabilisers after each move and press them back down onto the paving. The remaining points are collected at the rules for work at height.

Finally, think about what runs downwards. Cleaner tracking down the wall reaches your path, your planting and the shoes of anyone standing below, so keep that zone empty and hose the paving off at the close of each day. Wear gloves and goggles, certainly while rinsing upwards with the hose, and lay the hose in a generous loop so that it cannot drag tight against a standard. A hose pulled taut takes a bucket with it long before it takes you.