When a general contractor should self-perform the slab
When a commercial GC should pour their own slab and when to sub it out. Cost, schedule, quality, warranty, and what owners should look for in either approach. From actual Borderplex projects.
There is a recurring conversation in commercial preconstruction that goes roughly like this. The owner asks the general contractor whether they will pour the slab themselves or sub it out. The GC says "we self-perform site work and structure." The owner nods and moves on. Then six months later the owner is on the phone with us asking why the slab cracked at every cold joint and nobody can tell them who is responsible.
The conversation everyone should be having is more specific. Here is how to think about it.
What self-performing actually means
A self-performed scope is one the general contractor's own crews, own foreman, and own equipment execute. The wages on the timecard go to W-2 employees of the GC. The truck that hauls the concrete is owned or leased by the GC. The finisher that troweled the joint reports to the GC's superintendent, not a subcontractor's super.
This matters because the contract document, the insurance certificate, the warranty, and the recourse if something goes wrong all point at the same name. When the slab cracks, there is no fingerpointing because there is no other finger.
When self-performing the slab makes sense
The economics work when three things are true.
The GC pours enough concrete annually to keep crews productive. A foundation crew that only pours four projects a year loses skill between projects. They make mistakes setting forms, misread the soil prep, or hold the trowel too long. A crew that pours one or two slabs a month stays sharp.
The GC owns the equipment. Renting a 60-foot pump truck for every pour erases the margin you would otherwise capture by self-performing. The contractors who self-perform well own the pumps, the bull floats, the laser screeds, and the sawing equipment. They are not arbitrating between a rental yard and a project schedule.
The project schedule benefits from direct control. When the slab pour sits on the critical path and the next trade has been scheduled tight, having direct control over weather calls, mix design tweaks, and overtime decisions matters more than the dollars saved. The GC can hold their own crew an extra hour to finish a section. They cannot hold someone else's crew the same way without a change order conversation.
When subcontracting the slab makes more sense
For ground-up projects where the slab is a one-time scope and the rest of the work is interior, subcontracting is usually right. The GC does not have the volume to keep a foundation crew busy. Hiring a specialist who pours fifty slabs a year produces a better product than asking your in-house carpenters to fake it.
The same logic applies to scopes that need specific licensure or specialty equipment the GC does not own. Drilled piers, mass concrete, post-tensioned slabs. Those go to subs who do them every day.
What owners should ask
The right question is not "do you self-perform?" The right question is "what specifically do you self-perform on a project like mine, and can I walk a job where your crew is doing it?"
A contractor with confidence in their self-performed work will say yes to a walk-through this week. We have brought owners onto active job sites in El Paso on three days' notice. The crew is the same crew that will be on their project.
A contractor that hedges on the walk-through is signaling something. Maybe their self-performed work is one scope they advertise but rarely run. Maybe the crew they describe in the proposal is actually a sub they rebrand. Either way, the owner needs to know before signing.
The warranty conversation
Self-performed scopes carry the GC's warranty directly. Subcontracted scopes carry the sub's warranty, backed up by the GC's prime contract obligations. In practice, both should be backed by the GC, but the path to enforcement differs.
When a self-performed slab cracks, the owner calls the GC and the GC sends a crew. When a subcontracted slab cracks, the owner calls the GC, the GC calls the sub, the sub schedules a visit, and the timeline drags. Neither approach is wrong; the owner should know which one they are buying.
Where Expert Construction Group lands
We self-perform site work, concrete, and roofing across the Borderplex because we run the volume to keep crews sharp and own the equipment to make the schedule call without renting. We subcontract finishes, MEP, and most steel because we do not have the volume in those scopes to justify keeping crews on payroll year-round. Owners ask. We tell them which is which. Then we let them watch the work.
If you want to see how we self-perform a slab before you sign anything, send us the project. We will tell you what we would do, and we will let you walk an active pour before the conversation is over.