Bespoke Garden Decking in Cardiff

Timber or composite?

This is the first real decision and it changes the price, the look and what you do every spring. Neither is the right answer for everyone.

• Softwood. Lowest cost and easy to work. It needs cleaning and re-treating roughly annually to hold its colour, and it will silver if you let it. Boards can cup or twist if the substructure does not ventilate.
• Hardwood. Dense, long-lasting and considerably more expensive, with the hidden cost being labour — it needs pre-drilling and slower fixing.
• Composite. No re-treating, stable colour, and a higher up-front price. It expands and contracts more with temperature than timber does, so the gapping and the fixing system matter. Cheap composite scratches and fades; the mid-range and up generally does not.

What holds it up matters more than what you walk on

Decks fail from underneath. The boards are the visible part and the least likely thing to be wrong. What decides whether a deck is still solid in ten years is the substructure:

• Joist spacing. Set by the board being used and the direction it runs. Composite and diagonal laying both need closer centres than a straight softwood deck.
• Ventilation. Air has to move under the deck. A deck boxed in tightly to the ground traps moisture against the timber and rots from below while looking fine on top.
• Ground preparation. Weed membrane and a stable base under the frame, not a frame dropped onto soft soil that will settle unevenly.
• Post fixing. Posts into concrete or on galvanised anchors, not buried directly in soil where they rot at the ground line.
• Fixings. Stainless or properly coated. Ordinary screws react with treated timber and stain the boards as they corrode.

Raised decks, and where the rules come in

A low deck is generally straightforward. Once it is raised, two things change. A raised platform can fall outside permitted development — broadly, decking more than 300mm above ground level is the point at which it is worth checking rather than assuming. And a fall of any height means balustrade with proper handrail heights and spindle spacing, which is a safety requirement rather than a styling choice.

Overlooking is the other thing worth thinking about early. A raised deck that looks straight into a neighbour's garden is the most common reason a decking scheme attracts an objection.

Slip, shade and where the deck should go

Cardiff gets a lot of damp days, and a north-facing deck under trees will grow algae and get slippery whatever it is made of. Grooved boards help a little; position helps far more. Where a shaded spot is the only option, a grit-faced or textured board and a realistic cleaning routine are worth building into the plan rather than discovering in the second winter.

Looking after it

Softwood wants a wash and a re-treat most years, ideally in dry spring weather. Composite wants a wash and nothing else. Both want the gaps between boards kept clear, because trapped leaf litter holds water against the timber and against the frame below. Clearing the gaps once a year does more for the life of a deck than any product you can buy.