How do I lay timber decking in my garden in Hong Kong

I'm thinking of laying timber decking in my garden. Is this something I could tackle myself?

Constructing timber decking is relatively straightforward. Basically you construct a frame from wooden joists and then add deckboards to create a flat surface.

Mark out the area you want your deck to occupy with wooden pegs and string. This will help you visualise the size of the finished decking and also serve as a guide when preparing the site. Cut the four side joists that will form the outer frame of the decked area, and for the inside. cut the vertical floor joists that will be placed at 40cm intervals. Treat all cut ends with end seal preservative. Place all the joists in position and assemble the framework using three 7.5cm screws in pre-drilled holes at every joint.

You can now fit the decking boards on top. Cut the deckboards to length and seal all the cut ends with preservative. Place the first board flush with the face of the joist at the front of the deck and fix using 5cm screws in pre-drilled holes. Install the remaining boards leaving a 3mm gap between the boards to allow for any expansion of the timber. Finish by fitting fascia boards to conceal the end of the deckboards.

All materials are available from Hop Sze Timber at 425 Lockhart Road, Wan Chai (tel: 2833 6069). Treated pine costs HK$180 for a 2.8cm x 14.5cm x 300cm plank, HK$210 for a 1.4cm x 7cm x 300cm piece of deckboard.

What Wood Is Best for Outdoor Decking in Hong Kong?

Choosing the right timber is absolutely critical in Hong Kong. I have seen people lay standard pine decking only to have it buckle and rot within two years. Our combination of extreme humidity, intense UV, heavy rainfall, and the occasional typhoon means you need to think carefully about your timber choice.

Here is what I recommend based on nearly three decades of building decks across Hong Kong:

• Balau (also called Bangkirai) -- This Southeast Asian hardwood is my top recommendation for Hong Kong decking. It is incredibly dense, naturally rot-resistant, and handles moisture beautifully. Expect to pay around HK$350-450 per 300cm deckboard. It weathers to a lovely silver-grey if left untreated, or you can oil it annually to maintain the warm brown colour.
• Ironwood (Merbau) -- Another excellent tropical hardwood that thrives in humid conditions. Slightly more affordable than Balau at around HK$280-380 per board. It does bleed a reddish-brown tannin initially, so keep it away from light-coloured walls for the first few months.
• Treated pine -- The budget option at HK$180-210 per board. Perfectly serviceable if you commit to annual maintenance -- sanding and re-staining every year. If you skip the maintenance, it will deteriorate fast in Hong Kong's climate.
• Composite decking -- Not timber, but worth mentioning. Made from recycled wood fibre and plastic, it requires almost zero maintenance. Costs around HK$400-600 per board but lasts 15-20 years without staining or sealing. A good option for roof terraces where carrying heavy hardwood boards up stairs is impractical.

Whatever you choose, make sure all fixings are stainless steel. Standard zinc-plated screws will rust within months in Hong Kong's humidity. Stainless steel decking screws cost around HK$150-200 for a box of 200 from Hop Sze Timber. If you are building a gazebo alongside your deck, the same timber choices apply.

How Much Does Decking Cost Per Square Foot in Hong Kong?

This is one of the most common questions I get asked. The total cost depends on the timber, the substructure required, and whether you are building on a ground-level garden or a roof terrace (which is more complex).

Here are rough all-in costs per square foot, including materials and labour:

• Treated pine deck (ground level) -- HK$80-120 per sq ft
• Balau hardwood deck (ground level) -- HK$150-220 per sq ft
• Composite deck (ground level) -- HK$180-250 per sq ft
• Roof terrace deck (any material) -- Add 30-50% to the above for waterproofing membrane, drainage, and the additional structural work required

A typical Hong Kong garden deck of around 100 square feet will cost roughly HK$12,000-22,000 all in, depending on your timber choice. Roof terraces are more complex because you need to ensure proper drainage, lay a waterproofing membrane underneath, and often get building management approval before starting work.

Important note on roof terraces: If you live in a managed building, you will almost certainly need written permission from your building management office before constructing a deck on a roof terrace. Some buildings have strict rules about weight loading and drainage modifications. I have had projects delayed for weeks waiting for approvals, so start this process early. You should also factor in ongoing maintenance for your terrace surfaces to keep everything looking its best.

For ground-level gardens, particularly in village houses across the New Territories, Sai Kung, and Discovery Bay, the process is more straightforward. You will want to lay a weed membrane underneath and ensure the ground is well-compacted and slightly sloped for drainage. In Hong Kong's heavy downpours, standing water under a deck is a recipe for rot and mosquitoes -- neither of which you want.

Once your deck is built, protect the timber with a good quality oil or stain. I recommend Sikkens Cetol or the Osmo range -- both handle Hong Kong's UV and humidity well. For more on keeping outdoor timber in good condition, see my guide on repairing sun-damaged wood. Budget around HK$300-500 per year for maintenance products.

When Should You Call a Professional?

Basic decking on flat, solid ground is a manageable DIY project if you are comfortable with power tools. However, I strongly recommend calling in a professional for:

• Roof terrace installations -- Getting the waterproofing wrong can cause leaks into the flat below, which will cost far more to fix than the deck itself
• Sloped gardens -- These require a stepped substructure that needs proper engineering
• Decks larger than 150 sq ft -- The substructure becomes more complex and needs to handle significant weight
• Any deck that connects to the building structure -- This may require typhoon-rated fixings and must be done properly to prevent damage during storms

I have built decks everywhere from Sai Kung village houses to Mid-Levels roof terraces, and every job has its own challenges. If you are unsure, send me some photos on WhatsApp and I can give you an honest assessment of whether it is a DIY job or one for the professionals.

Last updated: March 2026