Cleaning roof tiles? Choose the right scaffold.

With a tiled roof on two storeys you choose the Altrex RS52, at 135 cm of deck width. That size is no luxury here: you work bent forward over the roof edge, you have a bucket or a tray standing beside your feet and moss and grit fall onto that same deck all day. On a narrow deck you are standing in your own mess within the hour and have to go down more often to sweep. All the available models sit together on the page about tower hire.

It pays to see this job apart from a general roof cleaning. There you spray a whole roof surface off in bands and what counts is your reach, while with tiles it is about the joints: you brush between the tiles, lift one now and then and work row by row. That asks for standing still on a stable deck and not for shifting constantly. The platform length of 245 cm decides exactly how many rows you take on from one position.

If you are working alone and the passage to the back garden is tight, the narrow RS51 at 75 cm is a workable alternative, though you keep considerably less room for your bucket and your tools. The MiTower manages only 6.2 metres and falls short on two storeys, and the RS44 room scaffold is an indoor model that passes a door from about 70 cm. For a garden with a narrow path that is a real trade off. See the difference in the comparison of scaffold sizes.

On a roof you cannot simply stand on, the question shifts: how far up the roof surface do you get from your deck. With a brush on a pole you manage roughly one and a half to two metres diagonally upwards from the gutter edge. If the ridge lies above that, you hire higher or you split the roof surface into two strips and set the tower higher the second time. On two storeys both approaches keep you inside the 8 to 12 metre band.

Work out your reach from the deck you will stand on and not from your head. When booking you give a working height, and that figure lies about two metres above your platform because your arm length is counted in. So put your deck at the height of the row of tiles you want to reach, minus those two metres, and measure the rest from the ground under the castors. The build that suits is shown at eleven metres of working height.

Choosing too tight shows up at once here. If you come half a metre short, you will still lean a knee on a tile to reach that last row, and that is precisely what you wanted to avoid with old tiles. Taking a more generous build costs you a couple of frames and nothing else. If you are working on a roof that only starts above the third floor, add the extra storey height neatly beforehand and round upwards.

Everything you brush off the tiles ends up under the set up: wet slabs of moss, sand, weathered grit and sometimes a shard. That heap grows faster than you think and turns the paving around the tower green and slippery. So choose a position on slabs or on the driveway that you can hose off afterwards, and lay sheeting over the border, the terrace and the garden furniture below. On grass the dirt spreads less far, but there the castors sink away once a few showers have passed over.

Keep the foot clear. The four stabilisers reach outwards at a slant, and besides them you want to get past with a wheelbarrow or a bucket to carry the waste off. Sweep that strip a few times a day, because as soon as you walk through it with wet soles you take the mess up the ladder with you. Lay a walking plank down once the strip beside the wall turns muddy. Setting the tower firmly on soft or sloping ground is covered in the piece on stabilising.

Along the wall the usual obstacles turn up on this job: a downpipe sitting exactly at the corner of your position, a shed against the brick, a low extension or a rooflight in the bottom part of the surface. The gully where you have to get rid of your rinsing water counts as well, because you do not want to block it with moss. Walk the round of the house before you hire the tower and settle per side where it can stand.

Per position you are busy longer than on smooth work. You brush the tile, you get the moss out of the joint, you rinse after and you check whether there is no crack under the growth. That takes an hour per 245 cm strip easily, and a roof edge ten metres wide gives four to five positions. For a complete roof surface that comes down to three to four days of scaffold hire; with a dormer or four separate surfaces the number of days runs on.

There is work afterwards that people forget to plan. The gutter fills with what you brush down and has to be emptied before the first heavy shower falls, and the paving under the set up needs a scrub. Reckon half a day for that, and do not forget you are walking to and fro with a wheelbarrow. If rain comes, working on is usually still possible, but with frost or a strong wind it stops and your whole schedule shifts a day.

Planning generously is cheap in this hire. The opening twenty four hours go at the full rate, but all the days that come after carry a discount of 95 per cent, so a spare day hardly becomes visible in your eventual rental price. That makes slack in your planning a sensible choice. You will find every amount per model and reach, including VAT, on the page of hire rates. Having to stop halfway because the van pulls up is a good deal dearer than that one extra day.

The deck length of 245 cm is the strip you clean per position, measured along the gutter. Finish that strip completely up to the height you can manage before you move, because coming back to a half done strip costs you a full repositioning. Start at the top and work towards the gutter, then the loosened moss does not rinse over tiles you have just done. That way you also keep track of which rows are ready and which are still to come.

Lean your weight on the guard rail and not on the tiles. A weathered tile that has lain in the sun for twenty years cracks under a knee or an elbow, and then you have gone from a cleaning job to a repair job. Use a brush or a lance on a pole to get further, and lay a batten or a roof ladder down when you do have to go onto the surface. Keep a few spare tiles ready below, then a breakage need not stop you.

What people misjudge is the number of times the tower has to move. For a roof edge of ten metres that is already four positions, and if you do the surface in two height strips it becomes eight. Every move costs you releasing brakes, stabilisers in, rolling, aligning and fastening everything again, and that adds up over a day. If you combine the work with cleaning out the gutter, do that per position in the same movement, so one move covers two jobs.

You get the scaffold supplied as loose parts, a complete set counted beforehand. Pick a spot for that stack beforehand that falls outside the zone where the moss will come down, so not right under the roof edge. A driveway or a path round the corner of the house is fine for that. Order it on a weekday and stay under 15:00, and the whole set lies ready the next working day, so you can still seize a dry spell in the forecast at the last moment.

Which day the set turns up and which day it goes again is yours to choose, and on this job the forecast is the deciding factor. Have the set come a day before your first brushing day, then you can build up calmly and begin with a full day. You put it up with the enclosed manual and the instruction video, preferably with two of you. Bear in mind that on the building day itself you seldom finish a whole strip of tiles, so count that day separately.

When you are ready you dismantle the tower and lay all the parts together where the van can reach; we drive them off afterwards. Rinse them first, because moss and green growth attach themselves to aluminium and you would rather not scrub on the collection day. Report it straight away if a part has been damaged on the way. What the bringing and fetching costs in your province stands including VAT in the overview of the transport charges.

The platform under your feet complies with EN 1004 and sits in load class 3, so 200 kg per square metre is permitted. With cleaning roof tiles you and a bucket of water and some tools stay well under that limit, so the problem does not sit there. Watch rather where that weight stands, because a full bucket at the edge is harder to lift than one by the ladder. The class itself is explained at the standard for mobile scaffolds.

The standing rules stay: castors braked as soon as anyone climbs on, moving only with an empty deck and nobody on it, and stopping when it blows too hard. On this job one more rule comes with it, namely sweeping. Lumps of moss and wet grit form a more slippery layer on an aluminium deck than water alone, so clear them after every row instead of at the end of the day. That one habit does more for your footing than any other.

Remember too that the norm applies to the tower and not to the roof itself. The tiles beside your deck are unknown territory and it is exactly the weathered ones that give way without warning. So do not sit or kneel on them to reach that one spot; move the set up instead. Keep the ground underneath clear as well, because a tile pulled loose or a falling bucket comes down precisely where somebody else is clearing up. The full rules are at working at height.