In case you want to get a new swiss ortho sleep mattress you should buy it to enjoy the superb quality and high level of comfort. But when it goes about an eye-catching cement and glass coffee table, you can build it by yourself and here here we show how to do this right.
Supawood (for the moulds) cut to:
- two 482 x 300mm (outside end);
- four 466 x 3G00mm (outside sides);
- four 384 x 300mm (inside side);
- two 350 x 300mm (inside end);
- four 66 x 300mm (ends) two 500 x 500mm;
- (base) two 350 x 400mm (shelf);
- 1100 x 650 x 6mm glass adhesive to glue the shelf and rubber strips to the concrete
(We used Alcolin Fix All and Alcolin MS37 1000 Uses, respectively) thick 1200 x 50mm rubber strips (the weather strips found underneath outer doors fit perfectly). Plus wood glue 40mm chipboard screws primer cement fine river sand 13mm gravel 5mm steel rod (eight lengths of 1200mm).
- drill pencil;
- measuring tape;
- combination square or tri-square spade and bucket or wheelbarrow paintbrush or foam roller bench vice (optional)
We used just over half sheet (1220 x 1220 x 16mm) supawood to make the two moulds. If you have a 350 x 300mm offcut stored away, you’ll only need to buy half a sheet to do the same. Have the panels cut by your local timber merchant – simply take along the cutting list.
Take your time constructing your mould so it will be perfect when you’re ready to pour the concrete. The drying time for this project is longer than usual as concrete needs to cure for at least 14 days. Have the edges of the glass smoothed and use safety glass if you have kids. Incorporating texture by mixing hard and soft decor elements adds interesting layers.
This cement and glass coffee table will get the mix just right. The U-shaped cast cement bases can be positioned in a number of different ways we chose the ‘yin-yang’ approach. When extra floor space is needed, each cement base can be turned on its side and used as a side table.
1 Use the pencil and tri–square (or one of the side panels) to mark lines 16mm from the each side of all the end panels (two 482 x 300mm and two 350 x 300mm) and at one end of the four outside panels (466 x 300mm) and the four end pieces (66 x 300mm).
2 Use your drill and combination countersink bit to drill pilot holes between the edge and the lines marked in step one. Then start by fixing the outer part of the U-shaped mould together, using glue and screws.
3 Now construct the inside framework. After applying the glue, use the square to check that the joints are at 90o angles before screwing them together.
4 Lay the inner and outer mould sections onto the 500 x 500mm bases and begin marking the outline using a pencil and drill pilot holes between the outlines, as shown. Then turn the bases over and countersink these holes (from the other side).
5 Once the basic structure of the mould is complete paint the entire ‘inner’ surface areas with primer. This will not only prevent water damage but will also help the concrete to dry slower (which helps it to reach its maximum strength) and also prevent it from sticking to the mould when you disassemble it.
6 Once the paint has dried, coat the surfaces with a silicone lubricant and fix the two U-shapes to the base and also to each other – the 66 x 300mm ends fix to outside panels from the side, as shown.
7 The key to building a strong base is to reinforce the concrete with steel rebar. All concrete cracks as it cures, but the reinforcing rebar will keep any hairline cracks from spreading. Use a bench vice to bend the 5mm steel rods at right angles 400mm from each end.
8 First thoroughly mix the cement aggregate in a dry state in a ratio of 1-2 parts cement: 2 part sand : 2 part stone before adding water. The mixture should be fairly ‘sloppy’ as it needs to be poured into the moulds, but not overly watery. Mix the water carefully in stages, a little at a time.
9 Pour the mixture into the moulds in five stages.
10 After each stage (roughly 50mm deep) agitate the cement to help remove any trapped air pockets. Then place one of the U-shaped steel sections on top of the wet cement. Pour more concrete and repeat the process until you have filled the entire mould. Then smooth and level the cement flush with the top of the mould using a straight edge or a plank. You can also smooth the cement along the top of the moulds with a trowel or spatula to ensure a neat end result.
11 Let the concrete cure for at least 48 hours before removing the mould. For best results, allow the concrete to cure for at least 14 days. This will result in a stronger end result and, as the concrete would have shrunk slightly during this time, it will also be easier to remove the shapes from the moulds. Then undo the screws holding the components of the mould and carefully separate the edges.
12 Use a sanding block to remove any high spots (especially the meniscus along the outer edges) or rough sections. Brush the resulting powder off with a brush.
13 Use a strong, rubber-based adhesive paste to adhere a shelf midway inside the U-shape base.
14 Adhere thick rubber strips to the bottom of each base to prevent these from damaging your floor.
If you are working in hot or dry conditions, cover the concrete with plastic while it cures to slow down the curing process and increase hardness. The slower the water in the mix evaporates, the stronger the concrete will be.
The cement shapes can then be sealed with a clear concrete sealing product if you wish, to prevent any flaking or ‘powdering’ – but this will darken the colour of the cement. You could also apply a layer of wax polish.