How to Build a Deck Around a Pool: The Ultimate DIY Guide

This six-step process assumes an above-ground pool and a rectangular deck—adapt as needed for in-ground pools or unique shapes. It’s detailed enough for beginners but thorough for seasoned DIYers. Safety first: work with a partner, wear gear, and double-check every measurement.

✅ Step 1: Prepare the Ground & Set the Foundation

A rock-solid base prevents your deck from sinking or tilting.

• Measure & Mark: Stake out your deck’s outline with string, ensuring it’s square (diagonal measurements should match). Add 10-15 cm beyond the pool’s edge for clearance—check with a tape measure.
• Clear the Site: Dig out grass, rocks, and roots to 5-10 cm deep. Use a rake and tamper to level—or rent a plate compactor ($50/day) for larger areas. Slope slightly away from the pool (1-2 cm per meter) for drainage.
• Set Footings: Dig post holes (60 cm deep, 20 cm wide) every 1.2-1.8 meters along the frame. Pour concrete footings (mix in a wheelbarrow) or use pre-cast deck blocks for speed. Insert anchor bolts into wet concrete; let cure 24-48 hours.

Pro Tip: Add a gravel layer (5 cm) under footings for extra drainage—Auckland’s rain demands it.

✅ Step 2: Build the Frame & Secure Support Posts

The frame is your deck’s backbone—build it to last.

• Cut Posts: Use 100×100 mm pressure-treated posts. Height = pool edge + 10 cm (for decking and a drainage gap). Cut with a circular saw; sand rough edges.
• Attach Posts: Secure to footings with post anchors and galvanized bolts. Check plumb with a level—adjust with shims if needed.
• Add Beams & Joists: Attach 150×50 mm beams to posts with joist hangers (galvanized for rust resistance). Space joists 40 cm apart, perpendicular to beams, and secure with screws or hangers. Check level across the frame.

Common Mistake: Skimping on bracing—add diagonal supports under beams if spanning over 3 meters.

✅ Step 3: Install Deck Boards

Here’s where it starts looking like a deck!

• Lay Boards: Start at the pool edge, leaving a 5-10 mm gap for water to drip through (use spacers). Run 25×140 mm boards perpendicular to joists for strength. For curves, trace the pool’s shape and cut with a jigsaw.
• Secure Them: Pre-drill holes to avoid splitting, then use stainless steel screws (2 per joist, 6 cm long) or hidden fasteners for a sleek finish. Space boards 3-5 mm apart—wood expands when wet.
• Trim Edges: Use a chalk line to mark straight cuts; saw off excess. Sand edges for a polished look.

Expert Hack: Rent a flooring nailer ($40/day) for faster installs—saves your knees and time.

✅ Step 4: Add Railings & Safety Features

Safety isn’t optional around a pool.

• Install Railings: Use pre-made kits (wood, composite, or aluminum). Posts should be 1.2 meters high, balusters no more than 10 cm apart (NZ code). Bolt posts to the frame; attach rails with screws.
• Non-Slip Surface: Apply a non-slip coating (like Cabot’s Aquadeck) or choose textured composite boards. Test with wet shoes—traction matters.
• Reinforce: Tighten all bolts and add knee braces under railings if they wobble.

Real-Life Win: Tom in Albany added solar-powered post caps—safe and stylish after dark.

✅ Step 5: Build Stairs & Access Points

Make entry a breeze.

• Plan Stairs: Aim for 3-5 steps (20 cm risers, 25-30 cm treads). Buy pre-cut stringers ($15 each) or cut your own from 50×250 mm lumber.
• Assemble: Secure stringers to the frame with angle brackets. Attach treads and risers with screws—double up on treads for durability.
• Add Handrails: Install on one or both sides (1 meter high). Bolt securely—wet hands need grip.

DIY Caution: Uneven steps are a tripping hazard—use a level obsessively.

✅ Step 6: Apply Finishing Touches

Make it yours—and make it last.

• Seal Wood: For pressure-treated decks, wait 30-60 days (wood must dry), then apply a waterproof sealant or stain (e.g., Resene Woodsman). Roll on two coats; reapply every 1-2 years.
• Enhance It: Add LED strip lights under railings, built-in benches, or planters. Edge with gravel or low shrubs for drainage and flair.
• Final Check: Walk every inch, jump lightly, and listen for creaks. Tighten loose screws; reinforce weak spots.

Pro Touch: Stain in a coastal blue or natural cedar tone—pairs perfectly with pool vibes.