A patio has to meet the same demands as a living room, says Heike Roettgen from the Federation of German Landscape Architects: it offers space for family life to develop and sparkle. Even the keen DIY enthusiast is best advised to leave the planning of a patio to a professional - especially if it is a structure physically attached to the house, such as a balcony.
"Its slope, base and waterproofing all have to be perfect so your home's walls don't get damaged by rainwater draining off the wrong way," says book author Falko Kullmann. Carefully sealing the point where a terrace attaches to the house wall is especially important. Genuine stone flagging has grown in popularity as a patio surface over the years. Concrete flagstones are cheaper than real stone ones, and are more robust and relatively easy to lay. The type of flagstone you choose, and its colour, should match your home's walls.
Don't forget that flagstones take on a darker colour when wet. "Don't skimp on cost when it comes to flagstones," advises Kullmann. A rule of thumb: the smaller the outdoor area, the larger the flagstones. "Large flagstones can be laid in a gravel bed with mortar filled between the gaps," says Kullmann. You won't be able to do that with small stones or tiles, because they wobble and break easier, which is why they need to be laid in a cement bed.
When it comes to wooden decking, grooved wood has been popular for many years. But don't imagine that grooves reduce the risk of slipping. When wet, a grooved board is just as slippery as a smooth board. Serrated decking also requires constant sweeping: "Otherwise plant particles and earth tend to collect in the grooves," warns Roettgen. "Wooden decks should be made from timber that's been impregnated against rot and left to dry for a long time," says Kullmann.
He recommends treating the decking with a wood stain, saying other products are less convenient: "Oiled timber tends to form watermarks when it gets wet. Varnish and paint will just flake off." Wood stain needs to be refreshed every two years. Woods suitable for decking include robinia, larch and oak. "These types of hard wood are weather-proof and can even be used untreated." But that's only the case when the surfaces can dry completely after every shower of rain. To emphasise the indoor-outdoor flow between the living room or dining room indoors and the terrace outside, some house owners like to choose the same surface for a patio as is used inside the home.
But a visual break between interior and exterior can look very attractive. "Planting moss and grasses in the gaps between the flags can give the exterior a certain something," advises Kullmann. But creating a indoor-outdoor break with a step does not make sense and can end up becoming a tripping trap. A level transition between the house and terrace is better, provided there is no risk of flooding on the balcony side.