Every tool your concrete project needs alongside it

Most residential slabs require 4 inches of compacted gravel or crushed stone base for drainage and frost protection. Slabs carrying vehicle loads (driveways, garage floors) typically need 6 inches. In cold climates with freeze-thaw cycles, 6–8 inches is standard to prevent heave. Because gravel compacts 10–20% after compaction, you need to order more loose material than the finished depth implies — for a 4-inch compacted base, order enough loose material for approximately 4.5–4.8 inches. The gravel calculator applies the compaction factor automatically.

Soil compaction is the process of mechanically densifying soil to reduce void space and increase load-bearing capacity. For concrete work, inadequate subgrade compaction is one of the leading causes of slab cracking and settlement — the soil beneath settles over time, creating voids that cause the unsupported slab to crack under load. Standard specifications require 90–95% of maximum dry density per ASTM D698 (Standard Proctor) for residential work, and 95–98% for commercial. The soil compaction calculator helps you verify target density and estimate the fill volume needed at your required compaction level.

For a standard single-skin brick wall using 215 × 102.5 × 65 mm bricks with 10 mm mortar joints, you need approximately 60 bricks per square metre of wall face. For a double-skin (full brick) wall, double that to 120 per square metre. Always add 5–10% for cuts, breakage, and waste. To get the mortar quantities, a standard 1:4 cement:sand mix uses roughly 0.5 bags of cement and 0.07 cubic metres of sand per square metre of single-skin wall. The bricks count calculator handles all of this automatically for any wall area and joint size.

Asphalt driveways cost $3–$9 per sq ft installed in 2026 vs $6–$14 for concrete. Asphalt is faster to install and easier to repair, but requires sealing every 3–5 years and resurfacing every 20–30 years. Concrete lasts 30–50 years with minimal maintenance, handles heavier loads better, and doesn’t soften in high heat — but cracks are more expensive to repair. In cold climates, asphalt is more flexible through freeze-thaw cycles. In hot climates, concrete holds up better. Use the asphalt calculator for tonnage and cost, then compare directly with the concrete driveway cost calculator for a like-for-like comparison.

Plum concrete (also called rubble concrete or cyclopean concrete) is a plain concrete mix in which large stones or “plums” — typically 150–300 mm in size — are manually embedded to reduce the total cement and aggregate consumption. It is used for mass foundation fills, retaining wall bases, and deep footings where strength requirements are modest and economy is the priority. The stones typically replace 30–50% of the concrete volume. Plum concrete should not be used for structural reinforced elements. The plum concrete calculator gives you the plain concrete volume and stone quantity needed for any fill area and plum percentage.