DIY Projects

Outdoor DIY Projects

Most pool covers do allow the odd leaf or three to land in the pool, but they certainly cut down greatly on the masses that otherwise would have gone in thanks to high winds.

For a 3×5.5m pool, you are looking at anything from R4500 to R5750 or so for a leaf cover, depending on the manufacturer. The one featured here came in at around R2800 or so.

But before we describe how it was made, a word of caution:

CAUTION:

We cannot stress this enough…This COVER IS NOT A SAFETY COVER. It could perhaps be used in conjunction with a purpose-made, factory-made safety net properly rated to take the weight of a small child or large pet, but on its own, THIS COVER MUST NEVER BE REGARDED AS A SAFETY COVER.

Having got that out of the way, here’s how it was made…

The first step is, of course, to confirm the pool’s size – in this case it is 5.5m x 3m – so the 3m-wide shade cloth chosen as the cover just barely covers the pool side to side (the coping slabs bring each side in by about 20mm or so) but it does keep the bulk of the leaves and debris – and small creatures – out.

When deciding on the length of shade cloth to buy, rather go over by a good metre so that you have sufficient on each end for a secure fixing.

This cover has made use of the attachment plates installed for an original leaf cover, and also the attachment dome-head bolts used for a solid cover for use during drought as a water-conservation measure.

If your pool is larger than the one featured here and/or there are no attachment points, you will need to adapt the design and perhaps even the direction of the shade cloth – for example joining two lengths edge-to-edge and positioning them across the pool’s width, for instance.

The main point being made here is how shade cloth can be secured very effectively when sandwiched between two flat strips of aluminium, secured tightly together with blind rivets, bolts and fender washers.

Right, let’s get to it…

Materials*:

  • 40% shade cloth – one sheet 6m long x 3m wide
  • Five 2.5m lengths of 30x2mm aluminium
  • Nylon webbing (15mm) – 3m
  • Steel hooks – 4x40mm – nine
  • Pop rivets – 4.8mm large flange – one box of 100
  • 5x25mm fender washers – 100
  • 6x32mm fender washers – 16
  • 5x16mm flat washers – pack of ten
  • 6x16mm bolts and nuts – 16**
  • Mounting tape (No More Nails) – 19mm – 2 rolls of 1.5m each
  • 5mmØ threaded rod 1m long – two lengths cut to eight lengths of 250mm each***
  • 6mmØ plastic tubing – one length of 3m
  • Polyethylene garden twine – one bobbin.
  • Clear marine silicone sealant – one tube

*1.The materials you require will depend very much on the size of the cover you need to make.

2. 40% shade cloth is used here, but it is available in a range of percentage ratings… select the one you feel works for you best, but bear in mind that the higher the density, the higher the cost, and the more shaded your pool will be from the sun’s warming effect.

Also note that shade cloth is available in a range of colours; green was selected in this case.

3. Note also that all the washers, nuts and bolts and hooks used here are stainless steel for best corrosion resistance.

**I substituted the standard hex-nuts for Nyloc locking nuts to ensure that the straps would always be securely attached.

*** This rod can be stainless, but as it would be covered in plastic tubing to protect the edges of the shade cloth, and be sealed with clear sealant

Method:

  1. Without a leaf cover pretty much every leaf and bit of garden debris that could go into the pool… did!
  2. Having selected the shade cloth and had it cut to length, the next step was to make it more manageable to handle during the construction phase, so I laid it out flat along a wall as shown here and decided to roll it around a 45mmØ curtain rail just over 3m in length.
  3. Line up the pole so that the warp – the threads running along the length of the shade cloth – are as close as you can get to 90° to the pole. In passing, the weft is the series of threads running across the shade cloth from side to side. I used some masking tape to secure the ends of the shade cloth to the pole.
  4. Then it was simply a case of rolling up the shade cloth, ensuring that its sides were always aligned and it was stretched out – to avoid any creases being created. Then I taped up the end to secure it. This makes the sheet easy to lug about.
  5. The next step was to make up a work surface to support the entire 3m width of the shade cloth. I made this up using 222mm planks as the work surface with 22×44 timbers across the back of them to secure them together and also to as a backstop for the roll.
  6. I cut one of the five lengths of flat aluminium into four lengths of 625mm (2500 ÷ 4 = 625mm) or as close as necessary. Then – with use of an end-stop – I aligned them.
  7. As you can see there is a slight discrepancy in lengths (the hacksaw blade does have a width, so it can introduce errors) so I marked off the cut line, using the shortest length as my guide.
  8. Then I clamped the four lengths very firmly to one end of the plank work surface…
  9. And trimmed them square so all four are now exactly the same length.
  10. Here are two lengths set up against the ends of two original 2.5m lengths. Joining the two will give a total length of 3125mm – allowing for a protruding length of flat aluminium of 62mm on each side of the shade cloth, give or take a couple of millimetres.
  11. Laying one pair together, I marked off the centrepoint – 1560mm. Then I laid the lower two strips underneath the top ones and in the following formation:
    Insert MICA – PLC-illi-flat-alu
    This ensures that the two uncut 2500mm lengths support the two 625mm cut lengths at each end.
  12. With the four pieces aligned and clamped together, I drilled a 5mmØ hole at the centreline at the centrepoint.
  13. Do this as accurately as you possibly can – it just looks better, and also, more important, makes aligning the holes easier.
  14.  Then I clamped the remaining four pieces of flat aluminium together in the same configuration, drilled the centre point holes through the lower two – using the upper two as my guide, and bolted them firmly together, but temporarily, to hold them in alignment.
  15. At each end I positioned the 6x32mm fender washers.|
  16. Then I drilled their 6mmØ holes and secured them each with a 16mm 6mm bolt and nut. The washers serve a dual purpose… ‘rounding off’ the square-cut aluminium flats, making them safer for passing feet, and also serving finally as sandwiching pressure plates for ends of the securing straps on each corner of the cover.
  17. I repeated the process where the 2500mm and 625mm strips meet, temporarily bolting them together as well. Note that the bolt passes through the junction between the aluminium flats. With these fixing completed across the entire lengths, all eight lengths of aluminium flats were secured firmly together. This allows all the remaining holes for bolts and rivets to be drilled in perfect alignment along the entire length of both assemblies.
  18. At 100mm on either side of the centre point, I marked off the positions for the middle strap securing bolts.
  19. I found using my home-made centring device made accurate marking off each 6mmØ drill hole a piece of cake.
  20. Here both 6mmØ strap attachment bolt holes have been drilled and the bolts inserted and tightened. It is as well to note here that it is essential that all 12 strap attachment bolts be at exactly the same distance apart. I selected 200mm, but you may need to adapt that if necessary. Giving two attachment points for each strap spreads the load on the aluminium flats. Note that I have also begun to label each hole position – in this case… ‘strap’.
  21. I repeated procedure on each end of the flats – again, note that the two strap attachment bolts are 200mm apart.
  22. Then I marked off the positions for the 5mmØ rivet holes, labelling each one as I went along. The spacing you select is up to you, but I spaced the rivets at 100mm centres between the strap attachment bolts and at 140mm centres on the open lengths. This means a total of 17 rivets and 6 bolts along the entire length at each end.
  23. Having drilled the holes for the rivets, I removed the securing bolts and marking the top of each top surface ‘TOP’ and ‘BOTTOM INNER’ on the upper surfaces of the lower pair of flats I taped the units together in their sets of four ( two lengths of 2500mm and two lengths of 625mm). It is essential that you mark the pieces as described here or in some other fashion so that you can properly align the drill holes. (In factories holes such as these are drilled according to a computer-guided drilling machine that ensures 100% of the time, but if you are like me and using the good old Mark 1 Eyeball, even being off-centre by a quarter of a millimetre from the centreline and reversing one of the flats can see the upper and lower flats out by half a millimetre. No one else light notice, but you will ALWAYS know the error is there.
  24. Now you can pop the roll of shade cloth up on to your ‘workbench’, rolling it out from underneath – i.e. rolling it away from you. And positioning the aluminium flats exactly parallel to the roll – another reason why your original rolling of the shade cloth around the curtain rail need to be very even and accurate.
  25. Mark off the shade cloth’s edge.
  26. With a few centimetres of the shade cloth unrolled, position the lower flat parallel to the roll – note how the warp is at 90° to the flat. The blokes doing the cutting at the shop do the best job they can, but their cut line can be a little ‘out’ so place the front edge of the flat in line with the shortest length of the shade cloth. Just to check what trimming you might be looking at.
  27. Now I cut short lengths of the mounting tape and stuck them over the bolt and rivet holes.
  28. And a double strip at the edges.
  29. The tape is for indoor use only, but the reason for using it here is that it is very thin, as opposed to ordinary mirror tape, and it serves to stick the shade cloth to the flats, making rolling the former around the shade cloth so much easier. Note that when sticking the shade cloth to the flats, there is no need to stretch it across the length of the flats; allow it to take its natural width of 3m.
  30. Confirming the warp is still at 90° you can now trim off the excess shade cloth, using the edge of the aluminium flat as your trimming guide. NOTE: I actually started rolling this the wrong way, and so had to change so that when the top flats are attached, the shade cloth would be sandwiched between both and the shade cloth passing out over the pool from between the two, and not from underneath.


    This illustration shows the correct orientation… if the shade cloth is stretched out over the pool from the bottom edge, there is a turning force on the straps, which will tend to orientate themselves at an angle. This will not only cause them to flex, exposing gaps, but more important, put a lot of strain on those areas of shade cloth in immediate proximity to the securing fended washers. Sooner rather than later, the shade cloth will tear and you will have to redo that end, provided you have sufficient shade cloth to do so. You will also notice that as the securing straps (black) are fasted to both the top and bottom of the flats, they (lower illustration) exert an equal force straight along the line of tension.
  31. Note how the tape keeps the end of the shade cloth in place.
  32. Once you have rolled the flats on to the shade cloth – I suggest about three turns – you can position the top flats on it – ensuring that the orientation is correct.
  33. I pulled the shade cloth snugly (don’t overdo it) on to the flats and then used a small flat screwdriver to shift the shade cloth thread aside, trying to not break any. An awl is better (but I had misplaced mine) and in retrospect, a Philips screwdriver would have been better as the flat blade I used did tend to snag the threads.

  34. Then I turned the first bolt through the shade cloth and secured it with a washer and nut. Bear in mind that the shade cloth going out over the pool should be between the two flats, as per the illustration above. The 6x25mm fender washer spreads the load and really secured the shade cloth to the flats. I suggest that you attach all the bolts first because if you pop a rivet in one of the holes intended for a bolt, you will need to drill it out.
  35. The rest of the holes you drilled are for the rivets – so mark them as such. I used a piece of scrap wood with a 10mmØ hole drilled into it to clamp the 5x25mm fender washers tightly in position. Remember, you cannot use a rivet to tighten a join, as you can with a bolt, so it needs to be tight in the first place. Note: the hole in the wood to accept the rivet pin is 10mmØ so that as the rivet is secured, the mandrel (the steel pin running through the rivet) is pulled up, expanding the lower end of the rivet pin and securing it against the washer, you won’t find it locking into the wood. Note the use of the two clamps to hold the washer tightly against the shade cloth and the aluminium flats.
  36. Top view of a rivet secured in position…
  37. …And the lower side, showing how the 5x25mm fender washer secured the shade cloth.
  38. Back to the bolts for a second… the junction between the 2500mm and 625mm lengths of flats is secured – and hidden – by being sandwiched between 6x32mm fender washers.
  39. Like so… these bolts can be tightened completely as they will not be coming off again – unlike the strap bolts that will be when the straps are fitted.
  40. See? The junction is almost invisible. Note also the use of the Nyloc nut to ensure the join remains secure from now on.
  41. The rivet at the centre point is intended to sit directly in the hole in the centre of the weir cover.
  42. I did a dry fit to get an idea of how long the straps should be.
  43. Then I cut six identical lengths.
  44. I sealed the ends with a small blowtorch to prevent the ends unravelling.
  45. Then I used a punch to make a 6mmØ hole about 20mm in from the end of each strap.
  46. Then used the blowtorch again, very carefully, to melt the treads. It is very important that the straps and holes be accurately cut and accurately punched, respectively, so that both straps take an equal share of the force exerted on them when the shade cloth is stretched out over the pool.
  47. Each end of each strap is secured under a 6x25mm fender washer. The only exceptions are the ends of the straps attached to the very ends of the flats, where they are secured under the 6x32mm fender washers.
  48. The straps have been secured with their bolts. Note that in order to equalise the tension on the components, the first two ends of the straps are secured to the upper and lower surfaces, then the other ends are secured to the lower and upper surfaces – so they cross where they meet the hook.

    This illustration shows how the straps cross over… one has been coloured light blue to show this more clearly. The detail lower right shows how the straps cross at the hook.
  49. The ends of the straps are secured with their bolts and washers snugly, but allowing a little movement as shown here…
  50. … And here. This ensures that as the cover is tensioned, the straps can find their natural position. Only then are they secured firmly in their final resting positions.
  51. Now for the tensioning straps… using these chain links to keep the cover tight over the pool. Use a bolt cutter or a hacksaw to cut out six links. Be quite liberal with the tensioning straps – I made mine about 600-700mm. Remember to melt the threads on each cut to stop them unravelling.
  52. Then use a 5mm punch to punch out the rivet securing holes.
  53. Slip two chain links on to end of the strap, fold it back and with a 5x16mm flat washer on the reverse side of the strap loop, secure the loop with a single rivet.
  54. Like this…
  55. Now repeat the process about 50mm back from the first loop to create a second smaller loop – as shown here. This holds the ends of the strap on the hook so you can easily tension it without having to stop the strap sliding around the hooks. Also note how the other end of the strap will be passed through both chain links and then back and under the one in front. When the strap is pulled tight, the link on the left is pulled hard up against that on the right, locking the strap in position. To release them, the links are pushed into a position at 90° to the strap. This releases the strap.
  56. This shows the attachment of the securing straps at the ends of the cover on the weir end.
  57. And this shows the attachment of the securing straps on the tensioning end of the cover. Note in both cases, the ends of the straps at the very ends of the flats are secured under the 6x32mm fender washers.
  58. And here is the completed arrangement. Not the use of some extra plastic tubing over the hook attaching the tensioning strap to the securing straps on the flats – stopping the hook from falling off every time you want to remove the cover for a lively dip in your leafless pool.
  59. To tension the sides of the cover, I would need side stays, so I measured the gaps in the reinforced attachment webbing along each edge of the shade cloth and decided that threaded rod cut to 200mm lengths would be about right.
  60. I cut the eight lengths required with a hacksaw and then cut eight 260mm lengths of plastic tubing with the utility knife.
  61. I slipped the rods into the tubing, centring them and sealed the ends with the silicone sealer.
  62. Like so…
  63. I punched a small hole – about 2mmØ in the silicone at each end and inserted a 100mm length of the polyurethane garden twine into each… though afterwards I discovered that only one length was required to keep the plastic-cover rod in position on the cover.
    I measured the distance between the edge of the cover to the securing plate installed with the first (factory-made) leaf cover.
  64. I measured the distance between the edge of the cover to the securing plate installed with the first (factory-made) leaf cover.

  65. Then I inserted the rods into position. Their purpose is to spread the load further along the edge of the cover and the plastic tube covering is to prevent the thread on the rod from chaffing the thread making up the shade cloth’s reinforced attachment webbing. I used a suitable length of the polyurethane garden twine on each, looped through the original hooks supplied with the first net, to secure the threaded rod in position. To apply equal tension across the width of the cover and on each rod, ensure that that the twine is centred on the threaded rod. Then I finally fully tensioned the cover along its length. Job done!
  66. The completed pool leaf cover. It has proved to be effective and cost far less than a manufactured version.

Project guide

Skill level: 5

Estimated time: a couple of weeks

Cost: R2800 or so – but this will depend very much on how large a pool you need to cover

Assistant: at various stages

Tools required:

Drill/driver, hacksaw or bolt cutter, pop riveter, socket and adjustable spanners, utility knife.

Panel:

These materials are available at Selected Mica Stores. To find your closest Mica and whether or not they stock the items required, please go to www.mica.co.za, find your store and call them. If your local Mica does not stock exactly what you need they will be able to order it for you or suggest an alternative product or a reputable source.