What Pad Preparation Includes in Folsom
Pad prep is the earthwork sequence from raw or improved ground to a compacted, level subgrade ready for concrete or gravel surfacing. We handle everything up to the pour — scope depends on what's currently on the footprint and what the finished pad is for.
- Site clearing — brush, vegetation, and surface debris removed from the footprint
- Demolition of existing improvements — old slabs, sheds, or structures on the footprint if present
- Cut/fill grading — establish level subgrade, balance cut and fill or import/export as needed
- Subgrade compaction to 90–95% relative density per CA HCD/IRC requirements
- Aggregate base (AB) rock — 4–6 inches of 3/4-inch crushed aggregate for slab pads
- Gravel surfacing for non-slab applications — compacted DG or road base finish
- Spoils and excess soil hauled to Kiefer Landfill
- Grade verification before concrete contractor mobilizes
Folsom Soil Conditions and Pad Requirements
Folsom's east-west soil variation is the main factor that differentiates pad prep costs across town. Valley-side clay and foothill DG require different approaches to reach the compaction spec the building department needs.
- West Folsom clay: seasonally expansive — moisture conditioning required before compaction; engineered fill may be specified by geotech
- East Folsom DG: loose and friable — native DG is not adequate subgrade for structural pads; AB rock placement is required
- Granite outcrops east of Folsom Blvd: can be encountered at 12–24 inch depth — adds equipment time and cost
- Sacramento County expansive soil maps: some Folsom valley-side lots on known expansive clay require geotech sign-off
- Compaction testing: nuclear densometer test by geotech firm — City of Folsom inspection before pour
- Imported fill: if cut doesn't balance and fill must come in, material is quarry-sourced and compacted in lifts
ADU Pad Preparation in Folsom's Older Neighborhoods
The Briggs Ranch, Natoma Station, and East Bidwell corridor lots are the most active ADU pad prep market in Folsom. These are typically 0.25–0.5 acre lots with enough backyard depth for a detached ADU after pool removal or existing structure demo.
- Common sequence: pool demolition → backfill/compact → ADU pad grading — one mobilization where access allows
- Lot sizes: Briggs Ranch and Natoma Station lots typically 0.25–0.5 acre — room for detached ADU
- California AB 68: ADUs permitted by-right in all residential zones — Folsom applies state standards
- City of Folsom compaction inspection: may be required before concrete pour — we coordinate scheduling when applicable
- Utility stubs: coordinate with your plumber before AB rock placement so stubs are not missed
- Access for concrete truck: we confirm truck access path during site assessment — tight lots may need approach work
- Combined scope (pool removal + pad prep): $14,000–$28,000 typical range depending on pool size and pad dimensions
Gravel Pads vs. Concrete-Ready Subgrade in Folsom
Not every pad leads to a concrete slab. Equipment storage, RV parking, shop staging areas, and some shed applications are finished with compacted gravel or DG. The earthwork is similar — the finish course and compaction spec are different. Know which you need before the job starts.
- Concrete-ready subgrade: compacted native + AB rock base, ready for vapor barrier, rebar, and pour — requires permit and inspection
- Compacted DG pad: cost-effective for equipment storage or non-structural use — DG is available locally in Folsom area
- Road base / AB rock finish: 4–6 inches compacted, suitable for equipment staging and parking on east Folsom lots
- Structural pads require inspection: if a permitted structure sits on it, the subgrade gets inspected
- Drainage slope: all pads need minimum 1–2% slope away from structure — we establish this in finish grade
- Non-structural gravel pads: typically no permit required — confirm with City of Folsom for your specific scope
Frequently asked questions
How much does pad preparation cost in Folsom?
Typical range is $3,500–$15,000. Simple pads on flat, cleared lots run $3,500–$6,000. Sloped east Folsom lots requiring significant cut/fill land in the $6,000–$12,000 range. Complex jobs with pool demolition, rock encounters, or large spoils volumes reach $15,000+. AB rock and spoils export are priced in the overall quote.
Does Folsom's soil type affect pad preparation?
Yes significantly. West Folsom clay lots may need moisture conditioning and engineered fill if the subgrade is expansive. East Folsom DG lots require AB rock placement since native DG alone won't hold up under a structural slab. We assess soil conditions at the estimate visit and adjust the scope and cost accordingly.
Does the City of Folsom inspect pad compaction before the concrete pour?
Yes. The City of Folsom requires a compacted subgrade inspection as part of the ADU and accessory structure permit process. We coordinate the inspection scheduling with your permit timeline. A geotech firm typically performs the compaction test; the city inspector verifies.
Can you prep an ADU pad on a lot where a pool was previously located?
Yes. This is a common Folsom sequence — pool out, site backfilled and compacted, then ADU pad graded. The key is confirming the backfill material and compaction match what the ADU permit set specifies. We work from your architect's plan and can coordinate the pool demo and pad prep as a single mobilization.
What is aggregate base rock and why is it needed on east Folsom pads?
Aggregate base (AB) rock is 3/4-inch crushed aggregate placed and compacted in a 4–6 inch layer under concrete slabs. Native decomposed granite in east Folsom lacks the stability and load distribution of processed AB rock — using DG alone as subgrade under a slab leads to settlement and cracking. AB rock is standard practice for any structural pad in DG soil areas.