Pointing joints? Choose the right scaffold.

For recharging the seams of a brick elevation the RS51 is the obvious choice from the fleet: a tower that builds only 75 cm wide. That dimension pays you back twice over. It travels along a garden path, through a side gate and down the strip beside the house where the boundary fence crowds in, and it shifts one bay along without your having to move the mixing station with it. The rest of the fleet is set out under the mobile scaffolds available to hire.

Up on the deck you barely miss the extra width on this sort of work. Your chest is close to the brickwork, you drive the mortar in with short strokes, and everything you reach for lies within half a metre: the iron, a small brush, a bucket of clean water and the portion you mixed a few minutes ago. What you do notice is how long the boards under your feet run, because that length settles how many seams fall inside one position.

The 135 cm model only starts to make sense when two of you are up there together, or when the whole tub travels up instead of small portions. That choice has a price: more components to carry round the back, and a build that will not pass everywhere. If you are cutting out first and pointing joints later, the balance tips differently. The two widths are compared under a side by side look at both tower widths.

Measure to the highest seam still waiting to be charged. On most terraced houses that is the soldier course or the last course of brick under the eaves, and it calls for a hired reach of six to eight metres. Working height is not the boards on their own: it is those boards plus roughly 2 metres that you still bridge with your arms raised. Stand at four metres and you reach six. That total is the figure you give when you book, and not the height of your gutter.

The starting point for the measurement is the ground the castors come to rest on. If the drive falls away towards the carriageway, if there is a sunken light well along the plinth, or if your terrace drops a step down into the garden, your baseline slips half a metre without your noticing. Where only the bottom two metres are being recharged, above a plinth that has drawn damp, you can hire considerably lower. The build behind an eight metre working height is worked out on that page.

Standing too low shows up immediately when you are pointing joints. Above shoulder height you can no longer pack the mortar fully home, voids stay behind the face of the seam, and the striking runs crooked because you are looking up at it from underneath. That top course comes back to haunt you later as a band in an odd colour with a different profile. Half a metre of reserve is cheap insurance when you hire a mobile scaffold, while a second build to reach that last course costs half a working day.

At the foot of the build, pointing joints puts more on the ground than the tower alone. Your mixing tub turns there, the bags of mortar mix lie dry under a sheet, and the hose from the outside tap hangs within reach so that your irons can be rinsed between bays. Reckon therefore on a band of level ground that is roomier on every side than the tower itself, with the four stabilisers reaching outwards and a walking route beside them that stays clear for your buckets.

The ground has to carry the castors without sinking, even after a day of working with water. Slabs, block paving and a firmed drive are all fine; a planted border or a newly sown lawn is not. Look at what sits beneath your position as well: a cellar hatch, a light dome over the crawl space or a freshly repaired plinth is not something to use as a bearing point. Uneven ground is dealt with in the advice on a sloping or soft surface.

Finally, work out where the mess is going to land. Filling drops mortar, and mortar bonds to paving and car paint harder than you would wish. Spread a tarpaulin below the strip you are charging, and move vehicles well clear before the first tub travels up. Where the hired build takes in part of the pavement, leave enough footway for a pushchair to pass, and ring the council to hear which permissions apply on your particular street.

Filling does not translate neatly into square metres per day, because you spend as long mixing and striking as you do charging. For the front elevation of a two storey terrace most people hire for three to five days, spread over four to six positions. Take in the flank wall as well, or find that cutting out has to come first, and it climbs. Add to that the round in which you go back over the bays you charged on the opening day.

Scattered through that period are hours when nothing can be done. A bay has to firm before it can be struck, and in warm weather you want to damp the fresh seam down a few times afterwards so that it does not dry too fast. If it freezes, or rain drives against the wall, you do not point at all and the whole thing slips a day. Those silent hours fall right in the middle of your hire period, so count them when you book.

That is exactly why the sums work out kindly on a job like this. The full rate applies to the opening twenty four hours only; every following day is charged with 95 per cent taken off. Two days of slack for the aftercare therefore weigh almost nothing, while booking tight leaves you at the collection van with half charged bays. So a generous reservation is the cheap choice here, and a tight count is the expensive one. To sharpen the estimate, read the guidance on how long to book a tower.

Boards of 245 cm sound generous, and they are, because when you are pointing joints your bay is bounded by the batch and not by the tower. An ordinary tub charges roughly one and a half to two square metres before the mortar begins to go off. So you work the full height of the wall that falls inside your position, from the topmost seam down to the plinth, and only when nothing there is still open do you roll one board length further along.

Keep every batch identical to the last. The same water, the same mixing time and the same sand out of the same bag, because a wetter tub dries lighter and you will see that on the wall as a block that does not match its neighbours. Where the seams have been cut out deep, charge them in two passes: press firmly to halfway first, then lay the finishing coat over it. Stuffing a deep seam in one go leaves voids behind the face for damp to find.

Strike with the iron that matches the width of the seam, at the moment the mortar feels thumb dry and no longer clings to your finger. Too early and you drag the seam open; too late and you scrape it to pieces. That moment comes round again in every position, so you keep walking the boards past the bays already charged. This is where people misjudge the job: you move the tower less often, but you stand still far longer.

What arrives at your address is a set of loose components, every one of them counted. Order on a weekday before 15:00 and those components are on the pavement the next working day; which date that turns out to be is yours to decide, as is the day we come back for them. For pointing joints the best delivery day is the one before your first bay, so that you build in the dry and start mixing the following morning.

Agree in advance where the components are to be set down. They go on the pavement or the drive, and that is precisely the place where you will shortly want your mixing tub, so keep two strips free instead of one. Putting the parts together is your own job and takes about an hour with two people. If you would rather not have a delivery day in the diary at all, the set can be collected by arrangement, free of charge, from Zeeburgerpad 89 in Amsterdam.

Let the forecast have a say in your dates. Night frost really does spoil this work, because fresh mortar that freezes has to be done again. So put your delivery day behind a cold spell and your collection day one day after your last bay, leaving room to dismantle and rinse at leisure. What the transport comes to in your own province is listed under the charges for delivery and collection, so there is nothing left to work out afterwards.

There is more weight on your boards on this job than you might guess. A tub of mortar, a bucket of water, half a bag of mix and your own body together climb faster than expected towards a ceiling of 200 kg for each square metre, the figure that EN 1004 attaches to load class 3. So spread that kit out along the length of the boards instead of parking tub, bag and buckets together in one corner, and bring the heavy material down before you move the tower on.

The castors go on the brake before you take the first rung, and they stay locked as long as anyone is working aloft. Never roll the build a step sideways with somebody aboard or your tub still up top, however short the shove to the following bay. If the wind gets up, stop: with a bucket in your hand and your face towards the wall you register a gust a second too late, and that second is the whole problem.

The hazards peculiar to filling are wet and slippery ones. Mortar droppings and rinsing water make the boards greasy, so sweep between bays and never let a puddle stand under your feet. An iron laid down on the edge for a moment is guaranteed to go over eventually, so put tools against the trap door rather than by the guard rail. If a path runs beneath you, close it off while you are up there working.