Timber or WPC terrace flooring. Your freedom.

There is no universally better option. Timber feels natural, varies in colour and grain and develops a patina outdoors; keeping the original colour requires regular surface care. WPC has a more uniform appearance and usually needs less maintenance, but its substructure, joints and expansion details must match the specific system. The choice should therefore reflect feel, desired ageing, maintenance effort, sun exposure and available build-up height.

A credible service life cannot be derived from the board name alone. It depends on the durability of both boards and substructure, rapid drying, adequate ventilation, working drainage, correct fastening and ongoing maintenance. Lignum recommends a substructure at least as durable as the decking. A specific number of years is meaningful only when product, build-up, use and warranty terms are all known.

No outdoor surface is slip-free in every condition. Profile, surface condition, moisture, slope, algae, leaves and dirt all affect grip; the Swiss BFU therefore recommends selecting the surface for its intended use and using tested values where the risk is higher. Regular cleaning and level installation without raised edges matter as much as the material. For pool surrounds, exposed stairs or demanding barefoot areas, the specific surface must be assessed rather than relying on a generic product label.

Direct sun heats every surface; darker colours generally absorb more radiation and can become noticeably hotter than lighter ones. Timber is often perceived as warm and comfortable underfoot, but it can still heat up considerably. For an unshaded south-facing terrace, colour, texture and a physical sample should be assessed in sunlight. Barefoot comfort also depends on clean edges, low-splinter grading, safe fastening and regular surface inspection.

Untreated timber changes colour under UV light and weathering, gradually developing a grey to silver-grey patina. This is primarily a visual change and, for suitable decking timbers, does not automatically reduce durability. Oil or an approved coating is useful when the original brown tone should be retained, but it must then be cleaned and renewed in line with the manufacturer's instructions. If natural greying is acceptable, many suitable decking timbers can be used without a colour-preserving coating.

Leaves, soil and organic deposits should be removed regularly because they retain moisture and can make the surface more slippery. For many timber and WPC systems, water, a suitable soft brush and a manufacturer-approved cleaner are sufficient; Braun suggests cleaning timber once or twice a year, while megawood recommends basic cleaning at least twice yearly. A concentrated pressure-washer jet can damage fibres or surfaces and is not a universal standard method. Always follow the product-specific care guide and test cleaners in an inconspicuous area first.

The substructure carries the load, controls board spacing, creates drainage and ventilation space, and receives fasteners and movement. Its material, centres, supports and screws must match the chosen board and installation situation; the maximum possible span is not automatically the best design. For timber, Lignum recommends a substructure at least as durable as the decking. A premium board on an unsuitable or permanently damp base is therefore still a poor overall system.

There is no single percentage that applies to every material and build-up. Lignum states at least 1.5 cm per metre for hard substrates beneath timber terraces; Braun mentions at least 1 percent for effective drainage, while individual WPC systems such as megawood may specify or recommend 2 percent. The product guide, drainage path, profile and substrate therefore govern the design. Water must drain in a controlled way, outlets must remain accessible and the construction must be able to dry quickly.

It may be possible, but a visual inspection from above is not enough. Once opened, the material and durability, moisture or decay damage, level, fixings, supports, centres, ventilation and drainage path must be checked. The geometry must also suit the new board and fastening system. Only demonstrably sound and compatible sections should be retained; damaged or incorrectly spaced parts need replacement or reinforcement.

No. Hidden fastening creates a calm board pattern, but it works only when groove, clip, screw, substructure and the material's movement are compatible. Braun lists systems with 4, 6 or 7 mm joints and distinguishes between grooved boards, strongly moving timbers, and timber or aluminium substructures. Visible A4 stainless-steel screws can be the technically clearer solution for ungrooved or highly moving timber. The approved system combination matters more than invisible appearance alone.

Timber and WPC change dimensions with moisture and temperature. Joints allow this movement, drain water and support airflow; perimeter clearances stop expanding boards from pressing against façades or borders. Exact values depend on the system: Braun clips create 4, 6 or 7 mm depending on the solution, while Lignum's general timber guidance states at least 7 mm between boards and 20 mm to adjacent components. Joints should therefore follow the product, board width and length, and installation situation rather than guesswork.

In principle yes, provided load capacity, waterproofing, available height, junctions and drainage have been checked. On hard or waterproofed surfaces, loads are distributed and the membrane is protected with compatible pads or pedestals; drains and inspection points must remain accessible. Existing slabs do not prove that the waterproofing is intact or the slope adequate. Planning therefore starts by establishing the water path, available build-up height and any special details at thresholds, railings and edges.

Timber naturally varies in colour and grain, greys outdoors, and swells and shrinks within limits; depending on the species, fine surface checks or slight distortion may occur. WPC can undergo product-specific colour maturation after installation and moves with temperature. Loose fixings, raised edges, persistent standing water, soft or decaying components and excessive deformation should not simply be dismissed as normal ageing. These changes should be documented early and assessed professionally.