Flat rooftops can offer great opportunities for conversion into attractive entertaining or relaxing areas, but contemplating a vast expanse of drab concrete or asphalt and envisaging how to attack such a problem, can be a rather daunting prospect.

Two important points need to be considered at the outset. Firstly, any objects on a roof top which are not securely fixed, need to be of sufficient weight or size that they will not move or blow away in strong winds.

Secondly, if there is a waterproof membrane on the roof, extreme care must be taken that the membrane is not punctured or damaged in any way. You will probably need to consult the building owner before placing any objects on the rooftop to ensure you are not faced with any potential liability issues.

The most important thing that then needs to be decided is what to install on the surface. If theres a waterproof membrane, then your choices are rather limited as its obviously not possible to lay conventional porcelain tiles. You could however lay interlocking plastic or rubber tiles although they would need to be of sufficient weight and securely joined so as not to blow away in strong winds.

One of the best options may be to cover the area with interlocking wood deck tiles. These tiles are generally manufactured using the same high durability lumber species as traditional decks but have wood slats screwed to an integral plastic base with inbuilt connecting tabs. The weight of the tiles and the gaps between the wood slats ensure the tile are generally unaffected by strong winds (except in areas prone to tornados or hurricanes). The tiles are typically available in 12 x 12 modules and are laid by just snapping the tiles together (see for example http://www.ezydeck.net). The gaps between the wood slats and the plastic mesh base also allows water to drain freely away so that pools of water do not lay on the rooftop.

The plastic bases of these tiles have multiple feet which distribute any load evenly over the surface below. A geotextile could be laid under the tiles as an extra precaution against membrane damage or if the building owner required extra assurance that the tiles would not damage the membrane.

Some manufacturers produce tiles in a variety of different designs, so it is possible to create borders, centerpieces, feature areas etc. to suit your individual preference. Or you could use different designs to divide the area in to several sections depending on how you plan to use the rooftop.

As well as the wood tiles, porcelain interlocking tiles are also now available which can provide additional opportunities for creativity in designing the total rooftop landscape. These tiles are designed to interlock with the wood tiles, so for example you could have a dining area paved in the ceramic tiles where tables and chairs are situated, surrounded by wood tiles.

If possible, try to divide the area into rooms by using a row of tubs with bushy plants, some trellis, modular fencing etc. With the addition of some large pots, attractive plants, and maybe a few favorite pieces of sculpture in strategic spots, that forsaken roof top can easily become an attractive and useful relaxing an entertaining area.