Gravel Under a Deck: Weeds, Drainage, and Depth
Gravel under a deck is a simple way to keep the area underneath clean, dry, and free of weeds. The usual approach is to clear vegetation, slope the soil so water runs away from the house, lay landscape fabric, and spread 2 to 3 inches of stone. Clean 3/4-inch stone or pea gravel are common choices. Gravel will not support the deck; footings do that. But it makes the space under the deck easier to maintain and helps reduce moisture that can encourage mold and rot.
Volume and tonnage calculator →Why put gravel under a deck
- Weed control: blocks sunlight and slows growth from below.
- Moisture: dries faster than bare soil and reduces humidity under the framing.
- Pests: fewer places for burrowing animals to hide.
- Appearance: a neater look, especially on low decks with visible gaps.
Choosing stone
| Stone | Notes |
|---|---|
| 3/4 in clean stone | Drains well, stays put, inexpensive |
| Pea gravel | Smooth, attractive, can shift |
| River rock | Decorative, more expensive |
| Crusher run | Packs firm but holds moisture in fines |
Clean stone without fines is best for drainage. See 3/4 inch clean stone.
Step by step
- Clear plants and debris, including roots where practical.
- Grade the soil to slope away from the house, ideally about 1/4 inch per foot.
- Lay landscape fabric with 12-inch overlaps, cutting around posts. See landscape fabric under gravel.
- Pin the fabric along seams and edges.
- Spread 2 to 3 inches of stone.
On low decks, it is much easier to do this before the decking goes on.
How much gravel
A 12x16-foot deck at 3 inches needs 48 cubic feet, about 1.8 cubic yards or 2.5 tons. See how much does a ton of crushed stone cover, or use the asphalt base calculator.
Drainage near the house
Make sure water from the deck and roof drains away from the foundation. If downspouts empty under the deck, extend them beyond it. See drainage gravel around a house foundation.
Gravel vs other options
| Option | Pros | Cons |
|---|---|---|
| Gravel over fabric | Inexpensive, drains | Leaves and debris collect |
| Concrete slab | Usable storage | Costly; must drain |
| Under-deck drainage system | Dry patio below | Higher cost |
| Bare soil | Free | Weeds, moisture |
Maintenance
Blow leaves out periodically, since decaying leaves on top of gravel become soil where weeds sprout. Top up thin spots every few years.
Bottom line
Put 2 to 3 inches of clean stone or pea gravel over landscape fabric on soil sloped away from the house to keep the area under a deck dry, tidy, and weed-free. Extend downspouts beyond the deck, and do the work before decking goes on if you can.
Questions people ask
Should I put gravel under my deck?
It helps control weeds and moisture, especially with fabric underneath.
How deep should gravel be under a deck?
About 2 to 3 inches.
What kind of gravel is best under a deck?
Clean 3/4-inch stone or pea gravel.
Do I need landscape fabric under deck gravel?
It is recommended to slow weeds and keep stone separate from soil.
Related guides
- Landscape Fabric Under Gravel: When It Helps
- 3/4 Inch Clean Stone: Uses, Weight, and Coverage
- How Much Does a Ton of Crushed Stone Cover?
- Drainage Gravel Around a House Foundation
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