Answers
Direct answers to the questions DIY warriors actually search. Each page has the math, a worked example, and a link to the calculator.
Concrete4 answers
How many 80 lb bags of concrete for a 10×10 slab?
Bag counts by thickness for a 10×10 ft pad, and the threshold where ready-mix wins.
ReadConcrete slab thickness guide: how thick does it need to be?
How thick a slab needs to be by use, sheds, patios, driveways, garages, footings.
ReadConcrete bag yield: cubic feet per bag (every size)
Cubic-foot yield for every common bag size, plus the math to convert volume to bag count.
ReadReady-mix vs bagged concrete: when does the truck win?
The threshold where the concrete truck wins on cost, time, and quality.
ReadFence2 answers
Gravel3 answers
Gravel shed base calculator + sizing guide
Cubic yards and tons of crushed stone needed for any shed footprint.
ReadHow many tons of gravel do I need?
The fast formula: square feet × depth ÷ 81 = tons of crushed stone.
ReadGravel driveway depth guide: layers, thickness, and total tonnage
The 3-layer system: #3 base, #57 middle, #8 top, total 8–12 in for a driveway that lasts.
ReadMulch4 answers
Mulch: bag vs bulk, when does bulk actually win?
The break-even between bagged and bulk mulch, usually around 5–6 cubic yards.
ReadHow much mulch do I need by bed size?
Bag and yard counts for every common garden bed dimension.
ReadMulch depth guide: how thick should you spread mulch?
Why 3 inches is the sweet spot, and why piling mulch against tree trunks kills them.
ReadTopsoil depth guide: how thick for lawns, beds, and leveling
How much topsoil for new lawns, garden beds, leveling, with volume math and ordering tips.
ReadPavers4 answers
Paver base depth guide: how thick should it be?
Base + sand layer thickness for paver patios, walkways, and driveways.
ReadHow many pavers do I need? Coverage by size and pattern
Pavers per sqft for every standard size, and how cuts inflate the count.
ReadPolymeric sand coverage guide
Bag count for joint sand on every common paver layout.
ReadPaver patio layers explained: from subgrade to joint sand
The 5 layers that make a paver patio last 25+ years, and what each one costs.
ReadDecking4 answers
Deck board spacing guide: gap, expansion, and fasteners
How big the gap should be, by material, climate, and season.
ReadHow many deck boards do I need?
Board count by deck size, board length, and orientation.
ReadJoist spacing and board count guide
Joist spacing rules + how OC choice affects board count and feel.
ReadDeck screw quantity guide: how many screws per board and per deck
Plan on ~350 screws per 100 sqft. Use 2.5 in for 5/4 boards, 3 in for 2× boards.
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