Concrete Driveway Replacement in Lost Creek, Texas

The City of Austin annexed Lost Creek in December 2015. At that point residents voted to turn the Lost Creek MUD into the Lost Creek Limited District, which still funds the common spaces and enforces the deed restrictions. Voters then approved leaving the city on May 4, 2024; the City Council passed the disannexation ordinance on August 29, 2024, and it took effect on September 10, 2024.

Beyond city limits, permits are the job of Travis County Development Services. Paving is on the County's list of what counts as development, and the County requires a permit for every development within its borders. The Limited District adds that Travis County, City of Austin and ESD 9 (Westlake Fire Department) permits may also be needed for a project, and that its architectural committee doesn't issue any of them. Ask the County how its rule applies to replacing a drive on your own lot before the old slab comes out.

Where the drive meets the street

Which agency approves the approach depends on the road. A county-maintained road means Travis County and its Driveway Permit; a state road means TxDOT; and a road the County doesn't maintain gets no County permit at all. Who maintains Lost Creek's streets since disannexation is the first thing to confirm. The County accepts only concrete or asphalt for an approach, ruling out pavers and stone, and caps its grade at 15% unless it signs off on a steeper one. On curb-and-gutter streets a property gets two approaches per street at most, spaced 35 feet or more apart measured between their inside edges, and the drive's grade can't pass 2% where a sidewalk crosses it.

Break-out and base

A replacement starts with getting the old drive out, and a cubic foot of normal-weight concrete comes to 140 to 150 pounds. Crushed, recycled concrete can serve well as the base course under the new slab. Under ACI 302, the base is a compactable granular material carrying 10 to 30% fines, free of clay, silt and organic matter, and the subbase and base together should total at least 4 inches.

Mix and joints

Driveway concrete should have a slump of about 4 inches, with slumps above 5 inches to be avoided (a Portland Cement Association warning) and a water-cement ratio below 0.50. NRMCA sets contraction-joint depth at one-quarter of the slab thickness or more, never under 1 inch, with the cuts made 1 to 4 hours after finishing using early-entry saws or 4 to 12 hours after using conventional ones.

Pouring in summer heat

In hot weather, the American Concrete Institute's specification caps concrete temperature at 95°F at discharge. NRMCA adds that chilling the mixing water can lower the concrete's temperature by up to 10°F, and using ice by up to 20°F. It also warns against adding water to a batch past 1½ hours old in hot weather, and calls for at least 3 days of curing. Heat is routine here: Camp Mabry, Austin's official climate station, averaged about 29 days a year reaching 100°F or above over 1991–2020. Seven days in, a new driveway has gained about 70% of its potential strength, but an RV, a large truck or anything similarly heavy should wait 28 days or more.