Installation work? Choose the right scaffold.

For installation work outdoors you want the Altrex RS TOWER 52, the wide version, 135 cm from rail to rail. That extra width is no luxury here. A drum of cable, a case of brackets, a cordless driver, a hammer drill for the penetration and a bag of clips all lie side by side without anything having to be shoved off the edge. Which other sizes are in the fleet you can read on the page about hiring a mobile scaffold.

If the passage to the back is too narrow for 135 cm, only the RS51 is left, 75 cm wide. You give up working room and the drum stays on the ground with just the cable going up. Where the installation work is indoors, in a tall hall or a stairwell, you take the RS44 room scaffold instead: it passes an interior door of roughly 70 cm and still reaches 3 to 4 metres. More on that choice is in the piece on choosing between the two.

If two of you are working, the wide deck wins every time. One holds the cable, the other drives the bracket, and you have to be able to pass each other without anybody being pushed against the rail. It counts with a heavier drum as well: that goes on the boards and not on a hook. Deck length stays 245 cm on both models, so with the RS52 you gain width, never extra length to work with.

The highest point on installation work is usually not the unit itself but the top bracket or the penetration just above it. Measure to that, not to the gutter. If the run climbs to the roof edge of a house of two storeys, you are around 7 metres. The RS52 reaches 14.2 metres as a model, but for this kind of work you stay in the lower part of that range and rent a build of 4.2 to 7.2 metres of working height.

Measure from the place the wheels will stand, and watch what lies under your run. A sunken cellar entrance, a garden falling away to the fence or a drive with a slope gives you half a metre of difference on its own. If the connection point is on the first floor with the penetration just under the frame, count the sill height in. What a chosen build means in practice is set out under the build that reaches 7 metres working height.

Renting too low is more of a nuisance on installation work than on painting. You cannot reach across with a long handle: a penetration is drilled square to the wall and a bracket is screwed at eye level, or the tray sits crooked. Stand short and the line ends at a point you cannot finish off neatly, and you still have to arrange a second build. So pick the build on the highest fixing point and not on the average.

On installation work the standing place follows the line you are laying, and that nearly always starts at the meter cupboard or the service box. Often that is the side elevation, a drive or the path beside an extension. Walk that run once with your head tipped back and count how many pitches it holds. Only then do you know whether you have enough flat ground to roll the tower from point to point without dismantling it every time.

A wide 135 cm pitch needs more room at the foot than a narrow one, because the stabilisers angle outwards and have to be able to spread fully. Along a side elevation that is exactly where the obstacles sit: the gas meter housing, an outside tap, the condensate drain from an air conditioner, a downpipe with a bend and the edge of a veranda roof. Measure that strip before you book, because a wide tower that will not pass the house costs you a day.

Think about your power supply on the ground as well. The extension lead or the generator cable must not run under a wheel or be pulled tight between the wall and a leg; lay it in a generous loop that follows the direction of travel. Keep the route to the meter cupboard clear too, because you walk inside several times that day to switch and to measure. On sloping ground, look at the piece on stabilising and tying in.

For a run along one elevation with a couple of penetrations and a connection, count on two to three rental days. Day one goes on building, setting out and drilling the penetrations, day two on pulling and bracketing, and day three on connecting, testing and clearing up. Each pitch costs you time on top, because shifting a wide tower is more work than shifting a narrow one: stabilisers in, roll, spread again and only then climb.

There are waiting moments in it that have nothing to do with your own pace. A penetration you seal with mastic or foam has to cure before you finish round it, and that time is on the tube. If somebody has to be at the meter cupboard inside to isolate, you work to their diary. And in the rain you simply stop electrical work on the outside. Take those three things into account when you fix your rental period.

On this job booking generously actually pays. The full rate covers 24 hours, and every rental day you add after that carries 95 per cent off. A margin of a day or two costs you little, while a second delivery on an overrunning job costs you far more time. With an inspection or a handover behind it, that extra day is earned back at once. What the rental price for your build comes to is shown on the page with the rates.

Per pitch you finish a stretch of 245 cm, and on a horizontal run that is exactly your module. So set your fixing points out in steps that fall inside that length and you never leave a bracket hanging halfway. Where the line climbs vertically you do the whole stretch to the top in one pitch. Count in advance how many times you have to shift; that number decides your days more than the metres of cable do.

With 135 cm of boards you can take the drum up instead of leaving it below. That saves pulling over a sharp edge and it saves walking. Lay it against the rail side, not by the hatch opening, and chock it so it does not roll while you unwind. Going up with it: a hammer drill with a long masonry bit, a driver, brackets and plugs in a tray, cable ties, a vacuum hose and your test meter.

What catches people out is the penetration. From outside you are through the cavity in half a minute, but inside you come out behind a kitchen unit, against a pipe or just under a skirting. So measure on both sides and have somebody inside watching while you drill. Angle the hole slightly down towards the outside so no water runs in. That costs you five minutes and stops you having to make a second hole from the scaffold.

The RS52 comes to you as one complete set of parts, counted out. On a wide build that is a substantial stack, so point out a spot beforehand where it will not be in the way: the drive, a piece of lawn or the path beside the extension. Do not lay it on the run itself, because that is where you will be working. Order on a working day, keep it inside 15:00, and the RS52 parts stand at your address one working day later.

Both dates, arrival and collection, are ones you name yourself, and on installation work you tune those to the people who have to be inside. Putting it together is down to you; nobody comes out to assemble it. For a wide build to just over seven metres two of you need about an hour. The manual and the assembly video walk through the order step by step, and that order matters more than speed at this height, because a part you forget sits at the bottom.

Bringing and collecting we charge as one fixed price per province, including VAT; for your address the amount is listed on the page with the delivery charges. Working near the city, you can also come and get the set yourself: without charge, once you have made an appointment, at Zeeburgerpad in Amsterdam. A wide set does not fit in every van, though. Afterwards we pick it up again, dismantled and stacked where the driver can reach it with the van.

A drum weighs more than you think, and on installation work there is sometimes a second person on the boards as well. So it helps to know that each square metre of your deck carries 200 kg, which is what load class 3 in EN 1004 sets. Even so, add it up: two people, a full drum, a case of brackets and a cordless drill puts you nearer that limit than painting ever does. Spread that weight over the whole deck instead of piling it by the hatch.

The basic rules do not change because you are working with cable. Wheels braked the moment anyone goes up, and nobody on the tower while it moves: take the drum off before you shift it as well. Stop in a hard wind, certainly if you have a long support or a length of tray to raise, which acts like a sail. After every move, check all four stabilisers before you take the first rung, because on a wide build they are not optional.

The risk that belongs to this job is the voltage. Isolate at the consumer unit, put a notice on it and measure for yourself that the point you are working on really is dead; somebody else in the house can switch the circuit back on. An aluminium tower conducts, so keep clear of an overhead line or a shared service head on the wall. Keep the zone below you free as well: a falling hammer drill is no small matter. The rules are on the page about the requirements for working at height.