Repairing a window frame? Choose the right scaffold.

For a repair to a single window you hire a mobile scaffold in the Altrex RS51 build. At 75 cm wide it comes through a garden gate, past a hedge and along the path between two houses, which here weighs heavier than deck area. The damaged window is often in a side or rear elevation where a wide frame simply will not pass. What else stands in the range, with all the sizes belonging to it, you look over on the page with our choice of mobile scaffolds.

On the deck you need little space for timber repair, but you do need ordered space. A chisel, a multi-tool with a plunge blade, a sanding block, a tub of filler, a knife and a vacuum nozzle all sit comfortably beside one another on a deck 75 cm wide. What you want above all is that nothing rolls or drops while you work with your face against the sill. A crate or a bucket that keeps everything upright serves better there than a wider frame.

Only move up to the RS52 at 135 cm if real volume has to go aloft, for instance when you replace a complete sill and a new two metre length of timber must lie on the deck. For point repair in a few places you gain nothing by it and pay mainly in carrying: more parts to lug round the back and more room needed to travel. Both models stand side by side in the overview of mobile scaffold sizes.

Your highest point on this job is not the glass but the junction above the frame: the head, the sealant joint over it and the piece of brickwork or render attached to it. Measure to there, because that is usually the very spot where water tracked inwards. For a window on the first floor you land on 6 to 8 metres. Then count back to your deck, since platform height plus roughly 2 metres of reach is what your hands cover, so the deck need not sit level with the head.

Take the ground under the castors as your zero point. If the side garden falls away towards the fence, or the build stands on a sunken terrace beside an extension, you start half a metre lower and need that half metre on top. Torn between two builds, look at what else has to happen at that window within the same hire period, such as the sealant joint or the top batten. What each build yields on the first floor is set out height by height.

Going too low costs you quality straight away in timber repair. Chisel with your arms up and you cannot see where the sound wood begins, so you take away either too little or far too much. Pressing filler home also asks that you look square at it, otherwise the knife will not run flat. And if you just fail to reach the top corner, you stand on the highest rung stretching at the exact moment you put force in. Take the next build up in that case.

Unlike facade work, your build stays in one place here, and that makes the choice of place important. Set it so the damaged part comes out in the middle in front of you and not in a corner of the deck, or you will be working at an angle all day. Under an upstairs window is often exactly where a border, a downpipe or a cellar light happens to be. Clear that strip out before the parts are delivered rather than shifting things afterwards.

The ground decides how much preparation you need. Paving and a drive are fine, a border of fresh soil is not: a castor sinks into it and then your deck sits crooked while you are leaning on a chisel. Lay paving slabs or thick boards under the castors in that case. Fold the stabilisers out afterwards and watch what lies in their path, because a shed or a bike rack tends to be right where they want to go. Taking up a slope is described under working on uneven ground.

Think about what ends up underneath as well. Chiselling out rotten wood sends splinters, old paint flakes and dust downwards, and all of that lands where the four stabilisers stand. Put a sheet or an old cloth there and you need not go hunting among the plants when the repair is finished. If part of the mobile scaffold reaches over the pavement, leave a gap for people on foot to get by, and check with your own council beforehand what a build on the footway is allowed to occupy in your street.

On this job you count in damaged spots, not in metres of facade. A soft corner ten centimetres across is half a morning; a sill attacked over its full width costs you a day. So before you reserve, walk the window over with a screwdriver and prod the timber at every suspect place. What you find then is almost always more than you saw from the ground, and it is that number of points your hire period rests on.

The real time eater is the waiting. Chiselling and cutting out go quickly, but after that the timber has to be dry before you fill, the filler has to cure before you sand, and the primer has to take before you finish. Every round asks you to come back onto the same deck, and in between nothing at all is happening. For a frame with two or three damaged spots you land in practice on three to four hire days, spread over working sessions of an hour or two.

That waiting is precisely why you book the mobile scaffold generously. The opening 24 hours make up the bulk of your bill, and each further day of hire is discounted by 95 per cent, so one more curing day disappears into nothing. Book tight and you stand with a half filled sill waiting for the van, then start over later. For a feel of how long others keep one, read the piece on hire days.

With a deck of 245 cm you stand in front of an average window frame in its entirety, from one stile to the other, without travelling. That is just what you want in repair work, because you switch constantly between the damaged point and the rest of the frame to see whether the line still runs true. If the damage on a wide frame sits right in the left corner, set your build a little to the left instead of neatly in the middle.

Take everything you need up in one go. Besides chisel, hammer and multi-tool, these are the things people forget: a vacuum or brush to clean out the chiselled hollow, wood hardener, tape to mask off the sealant joint and a moisture meter if you own one. Climbing down to fetch something costs a few minutes each time, and at three or four rounds a day that mounts up. Hang a tool bag on the guard rail where the small stuff stays upright.

The extent of the damage is where nearly everyone misjudges. Rot runs on under the paint and seldom stops where the finish splits open, so the hole grows further than you estimated the moment you start chiselling. Take a spare tub of filler up with you for that reason. Allow for it in your planning by not basing the hire period on that first impression. If the whole frame turns out lost, you move on to replacing window frames with the build already standing.

What lands on your pavement is a full set of loose parts, counted and bundled. A reservation settled on an ordinary working day, with 15:00 as the cut-off, is scheduled for delivery the day after. Point out beforehand where those bundles may lie, and keep the strip under the window free, because that is exactly where your build is going to stand. Tubes lying between your feet during assembly cost nothing but time and temper.

Putting it together is work for you, not for us. We erect no scaffold and never deliver one assembled, but you get building instructions with it and there is a video running through the order of frames, braces and deck. With two people you are busy for about an hour. If you would rather come yourself, the set is ready by appointment at our depot on the Zeeburgerpad in Amsterdam, without any charge attached to that.

When the material arrives and when it goes away again you enter yourself when reserving, and with timber repair it pays to think that through. Filler and paint want dry weather, so let the mobile scaffold arrive as a settled spell begins rather than on the very day the rain sets in. What the transport costs in your province is stated in the overview of delivery and collection charges, so you can reckon it in beforehand.

Each square metre of the deck is rated for 200 kg, the load class 3 figure that EN 1004 lays down. In timber repair you stay well under that, even with a second person and a box of tools up there. More important is that the force on this job works horizontally: every blow on a chisel pushes you away from the wall. So work with short, controlled blows and never lean your weight against the guard rail to make extra force. Heavier chisel work you do low down.

The brakes go on the castors the moment you climb up and stay on until your work for that day is finished. Never move the mobile scaffold with tools or with somebody on it, not even that one bit to the left. If it blows hard, you stop: correcting a multi-tool at height while you yourself are being shoved about is not a combination you want. Check the four stabilisers after every move and set them tight against the ground again.

What makes this job its own is that things drop on two fronts. Chiselled out timber and old paint flakes come off the frame, and on an old window those flakes may hold lead; wear a dust mask then and catch the material instead of letting it blow about. Underneath runs the path to the back door, which is where the debris ends up. Fence that strip off while you work. The complete list of rules sits in the article on working at height.