Shed and equipment pads are usually reinforced slabs over compacted soil and a base, kept out of easements and set high enough to drain. Workshops and garages need thicker slabs with thickened edges or grade beams. Foundations for additions need a permit, a design suited to expansive clay, and inspections. Contact Texas 811 before digging.
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Storage sheds, workshops, detached garages, carports, generator pads and room additions all need something solid underneath. In Greater Houston that something is almost always a concrete slab, because slab-on-grade construction is the norm here. A simple pad for a shed is a modest project. A foundation for an addition or living space is an engineered piece of the house that has to work with the clay the rest of the house sits on.
Common slab and foundation projects
- Pads for storage sheds, playhouses and garden buildings
- Slabs for workshops, detached garages and carports
- Pads for standby generators, pool equipment and AC units
- Foundations for room additions, sunrooms and enclosed patios
Sheds and equipment pads
A shed pad is usually a reinforced slab over compacted soil and a base, often with a thickened edge. Size it to the building plus a little extra, keep it level for the structure but high enough that water drains away, and confirm it meets setbacks and stays out of easements. That last point matters here: many Houston-area lots have utility and drainage easements along the back or sides, and HOA and township standards often bar slabs from them. The City of Katy lists storage buildings among the work that needs a permit, and other cities set their own thresholds. Check before you pour.
Elevation and flooding
Much of the region is flat and low, and parts of it sit in mapped floodplains. Where a structure goes and how high its slab sits can affect how it fares in a heavy storm. Some permit processes treat floodplain lots differently; Harris County, for example, says new development in the floodplain doesn't qualify for its minor site development review. If your lot is near a bayou or creek, ask about floodplain rules early.
Workshops and garages
A slab that holds vehicles or heavy tools needs more thickness and reinforcement than a shed pad, plus thickened edges or grade beams to carry the walls. If you plan to air-condition the space, ask about a vapor retarder, and plan where plumbing and electrical conduit go before the pour.
Additions and structural work
Foundations for additions carry the structure and must follow the building code your city or county has adopted. Several area cities, including Katy and Sugar Land, enforce the 2021 International Codes. That typically means a permit, an engineered design suited to the soil, and inspections before concrete is placed. The tie between a new foundation and the existing one is an engineering decision on expansive clay, because the two can move differently. Texas doesn't issue a statewide license for general or concrete contractors, but cities require permits, some require contractor registration or proof of insurance, and electrical and plumbing work is licensed by the state. Concrete crews commonly pour these foundations under a builder who holds the permit.
Before you dig
- Contact Texas 811 so underground utilities are marked before excavation.
- Locate sprinkler lines, septic components if you have them, and drainage pipes.
- Get HOA or township approval in writing if your community requires it.
Questions to ask
- Does this project need a permit, and who will pull it?
- How thick is the slab, and what base and reinforcement are included?
- Is an engineered design needed, and when are inspections?
- How high will the slab sit relative to the yard and the house?
Planning a building or addition? Request a slab or foundation contractor and include the structure's size and use.
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Frequently asked questions
Do I need a permit for a shed slab near Houston?
Often. The City of Katy, for example, lists storage buildings among work that needs a permit, and other cities set their own size thresholds. HOAs and township standards may also bar slabs from easements. Check with your city or county and HOA first.
Does Texas license concrete contractors?
Texas doesn't issue a statewide license for general or concrete contractors. Cities require permits, and some require registration or proof of insurance; Pearland, for example, asks contractors for a certificate of insurance. Electrical and plumbing work is licensed by the state.
Can an addition's slab tie into my existing foundation?
It can, but on expansive clay the new and old foundations may move differently, so how they connect is an engineering decision. Expect an engineered design, a permit and inspections before the pour.
Sources and further reading
- Houston Permitting Center: Residential Driveway, Sidewalk, or Curb & Gutter Permit
- Harris County Office of the County Engineer: Minor Site Development & Driveways
- Harris County Precinct 2: Service Request Guidance (culverts and driveways)
- The Woodlands Township: Residential Design Review Committees
- The Woodlands Township: Residential Development Standards (2024)
- City of Katy: Permit & Building Services
- City of Sugar Land: Residential permits
- City of Pearland: Contractor Requirements
- City of League City: Building Department Fee Schedule
- Harris-Galveston Subsidence District
- Houston Geological Society Bulletin: Beaumont Formation clays
- Texas A&M AgriLife Extension Service
- Houston Public Works
- Texas Department of Licensing and Regulation (TDLR)
- Texas 811: call before you dig
- American Concrete Institute (ACI)
- Portland Cement Association (PCA)