How to build a concrete slab in District of Columbia

Permits & code in District of Columbia

State-level rules only — cities and HOAs frequently add stricter requirements. Always confirm with your local building department before you dig.

What most people get wrong

• Pouring straight onto uncompacted soil. Compact the base in 2" lifts or you'll crack.
• Skipping the vapor barrier — moisture wicks up and destroys anything you put on top.
• Screeding without a wet edge. Cold joints show as permanent lines.

The 5-step concrete slab plan

1. Step 1
   Confirm site and permit path
   Locate property lines, call 811 for utility marking, and check whether your city/HOA needs approval before you break ground.
2. Step 2
   Order materials
   Use the shopping list from our planner. Confirm delivery vs pickup — bulk lumber and concrete are usually cheaper delivered.
3. Step 3
   Lay out and prep the site
   Batter boards, string lines, level the base. Getting this right saves days later.
4. Step 4
   Frame the structure
   Follow the cut list. Check for square with the 3-4-5 method every few pieces. Fasten with the right structural screws.
5. Step 5
   Finish and inspect
   Sand, stain/seal, and (if required) schedule your final inspection before backfilling or closing anything up.