Confirm the deck can support the plan
For unusually heavy pieces, large planters, fire features, spas, or concentrated loads, seek appropriate professional advice. A heavy table may be manageable while an oversized storage box filled with dense items creates a different load pattern.
Protect boards and coatings
Use feet or glides recommended for timber, composite, tile, or membrane surfaces. Avoid trapping wet debris under broad bases. Lift furniture when moving it rather than dragging it across boards or waterproof coatings.
Plan for wind
Upper decks can be much windier than the garden below. Lightweight chairs, umbrellas, covers, and cushions need secure storage or restraints. Never rely on a closed umbrella alone to make a poorly anchored base safe.
Leave inspection and drainage access
Do not permanently block drains, scuppers, flashing, service panels, or areas that need periodic inspection. Arrange furniture so leaves and dirt can be removed before they hold moisture against the deck.