Coating a concrete floor? Choose the right scaffold.

For the work above a concrete floor you hire the Altrex RS44 room scaffold. That model is made for indoors: it comes through an internal door from about 70 cm, so you get it from the hall into the garage or from the utility room down to the cellar without dismantling anything. An ordinary tower jams in a doorway like that. Which sizes belong to it is shown under hiring a room scaffold. Measure your narrowest door frame before you order.

On this job what the scaffold does to the floor counts as well. You roll it back and forth over precisely the concrete you are going to coat, so you want a light build with clean wheels and no heavy chest dragging scratches across it. The room scaffold is the right size for that: big enough to stand on with a light fitting in both hands, small enough to move on your own. A deck of 245 cm gives you the length to finish a row of lamps.

Is the space higher than four metres, a shed or a lock-up with an open roof, then this model falls short and it is better to hire a mobile scaffold, for instance the narrow RS51 of 75 cm. That still passes a double door or a roller shutter, but no longer a normal internal door. So measure the clear height to the ceiling first and the way in afterwards. Where the two models differ is set out in the comparison of the two types.

The highest point here is the ceiling itself, or whatever hangs beneath it: a pipe clip, a cable tray, the gear of a garage door. In a garage or a cellar that sits at two and a half to three metres, and then you hire a working height of 3 to 4 metres. That figure is the height of your deck with about 2 metres of reach on top, so your platform ends up at one to two metres. There is no sense in hiring higher than the ceiling.

Measure from the concrete floor the wheels come to stand on, not from the threshold or the drive in front of it. In a cellar that easily accounts for half a metre, and in a garage with a sunken pit or a drainage channel your starting point differs from place to place. Where the floor falls away to a gully, measure at the lowest point, because that is where the tower stands furthest from the ceiling. A reach of 4 metres working height shows which platform heights fit inside it.

Choosing too low takes its revenge immediately on ceiling work. Stand under your work rather than beside it and your arms stay above your head, everything you unscrew drops in your face and you go at half speed. On a ceiling you want your head just below the soffit, so you work with your elbows bent instead of straight. Pick too high and your head is against a beam or a clip. So take the reach that suits a room on the ground floor.

What is unusual about this job is that your standing place and your workpiece are the same thing: the room scaffold stands on the concrete floor you are going to coat. That is the best base you could wish for, flat and load bearing, but watch two things. Concrete that has not been ground yet is full of dust, and dust under a wheel means the brake has less grip. So sweep the spot where you put the tower down and keep a broom within reach.

The second point is the space around it. A garage or workshop is full: a car, a bench, racking, a boiler in the corner and bikes along the wall. The stabilisers have to be able to come out, so get that lot out before the scaffold arrives and not while you are already building. Where the floor falls towards a drainage channel, position the tower so that no single wheel drops into it. One wheel in a channel puts the whole build out of plumb.

In an enclosed room think about light and air as well. The moment you take the fittings off to do the ceiling you are standing on a platform in the dark, so hang a work lamp somewhere other than where you are working. Ventilate as well: in a cellar without a window everything you release stays hanging. Arrange that before you hire the room scaffold, because building in a half full room with poor light is a bad start and costs you an hour.

This job falls into two parts and only the first part asks for a scaffold. Cleaning the ceiling, making good the walls right to the top, taking down or replacing fittings and tidying pipework costs you two days in an average garage. The coating itself, with grinding, vacuuming, primer and two coats, takes another two to three days after that, but by then the room scaffold has long been outside. So hire it for the first block and not for the whole job.

That first block still holds moments of waiting. Fresh paint on the tops of the walls has to be dry before you carry on beneath it, and an electrician wiring up the fittings comes on his own day. Reckon on three to four rental days rather than two, then, with the collection on the morning you start grinding. The room stands empty at the point where dust free working really counts and no tubes are left in the way.

Taking those days generously need not cost much. The first 24 hours carry the full rate on their own; every rental day after that counts with 95% off, so a spare day for the electrician barely weighs. What you do want to avoid is the room scaffold still being indoors when the primer has to go down. Set that collection date sharply even so. Judging such a period is covered at hiring by the day or by the week.

From the platform you finish a strip of ceiling per position about as long as the deck you are standing on, so 245 cm, and as wide as you can get without stretching. In a garage of six by three metres that means some four positions for the ceiling alone. Keep to one fixed direction while you do it, from the back wall towards the door for instance, so that you finish at the way out and not in the furthest corner.

What you do from the room scaffold is everything above shoulder height: brushing and painting the ceiling, the top fifty centimetres of the walls, clipping up cable trays, fitting a smoke alarm or a light and strapping loose pipework. What you do not do from it is the floor. Coating goes on from the floor itself, walking backwards towards the door, and you want that done with no wheels, legs or bucket on the concrete. That is the entire reason for this order of work.

Repositioning indoors goes faster than outdoors, because the floor is flat and you are not wrestling stabilisers over a garden path. People still underestimate the number of moves: every hole drilled somewhere else is another shift. So take up in one go what you need, from plugs to a vacuum hose, and lay a piece of cardboard on the deck for your tools. If there is ceiling work with paint as well, plan it into these same positions.

The room scaffold comes as a counted set of loose parts, and on this job you do not want that stack lying on the concrete floor. Ask the driver to put the set on the drive or in the hall and carry it in piece by piece. An order that reaches us before 15:00 on a working day is ready for you the next working day. Measure the way through beforehand, because a garage is sometimes reachable only through a narrow utility room.

You decide which morning the set arrives and when it leaves again, and on this job that second moment matters most. Put it on the day before the primer goes down, so the room can be empty before you start. Building is your task: with the manual and the instruction video the room scaffold goes up in about an hour, and with this model you manage it alone. The step by step build instruction sets out what goes where.

Afterwards you take it apart and we load it back into the van, so have the parts waiting outside or in the hall and not in the middle of a floor that is curing. Collecting is allowed too, by appointment in Amsterdam, and a roomy van is enough for a room scaffold. What delivery out and back costs per province is at the delivery rates per province. Count that amount into the budget for the whole job.

A room scaffold sits under EN 1004 just like the rest, in load class 3: that permits 200 kg on every square metre of deck. For ceiling work it sounds generous, until you add up a tool chest, a drill, a carton of new fittings and somebody working beside you. Spread the weight over the platform instead of putting it all beside the hatch. More about that limit is in the explanation of what a scaffold may carry.

The fixed rules stay exactly the same indoors. Brake the wheels before you step on, let nobody stand on the tower while it travels, and put the stabilisers out again after every move. Wind plays no part inside, but a draught through an open garage door does, certainly with sheeting hanging on the frame. Wedge that door or shut it while you are up top. A build that shifts half a metre while you are drilling throws you off balance.

The risks that come with this job arrive from above and from below. Above you are working on electrics, so pull the circuit before you unscrew a fitting, even when you are certain the switch is off. Below you lies hard concrete with no grass or sand to break a fall, so let nothing stick out over the guard rail. Freshly ground concrete is powder slippery too; sweep it before you shift the tower again. The other rules for working at height hold in full.