Generators, HVAC units, transformers, and tanks all need a concrete foundation that holds them steady through years of operation. We pour engineered equipment pads that carry the full loaded weight, position anchor bolts to match the equipment's frame, and isolate vibration where the equipment spec requires it. Every pad starts with the equipment cut sheet and ends with a written estimate.
A pad that looks right can fail silently. The concrete slab must carry the equipment's full weight when it is running (not the dry weight from the spec sheet, but the weight with water, refrigerant, or fuel inside), resist the vibration and movement the equipment generates during operation, position every anchor bolt so it threads into the equipment's mounting frame without forcing or shimming, and remain stable through Boston's freeze-thaw cycles.
We start with the equipment cut sheet to understand the footprint, loaded weight, anchor pattern, and any vibration isolation requirements. The slab is sized to those specs, reinforced to carry the loads, and the anchor bolts are positioned using a template built from the equipment's mounting frame so they land in the exact spot the installer expects.
We collect the equipment's footprint, loaded weight, anchor bolt pattern, vibration class, and any isolation requirements from the supplier or your facility team. This drives every decision about the pad's size, depth, and reinforcement.
Excavate and prepare the base
For exterior pads, we dig below Boston's frost line, compact the subgrade, and place a gravel base to the engineered depth. Interior pads on existing slabs may tie into the floor depending on the load and site conditions.
Build forms and set anchors
Forms are built to the pad's final dimensions, rebar is tied per the load calculations, and anchor bolts are positioned using a template that matches the equipment's frame. Vibration isolation embeds are placed if the equipment spec calls for them.
Pour, finish, and cure
Concrete is placed and finished to the elevation the equipment expects. The pad is protected through cure, and as-built dimensions are verified before the equipment installer arrives.
Common pad failures
Why Anchor Bolt Position Matters Most
An equipment installer showing up with a generator or HVAC unit that cannot bolt into the anchor bolts because they are out of position creates a costly delay. Most equipment pad disputes trace back to anchor bolts that ended up a half-inch off the equipment frame. We template every anchor pattern from the equipment cut sheet and verify position during the pour, not after it hardens.
Coordinate with the equipment supplier early so the cut sheet is accurate and drives the pad design. Equipment pads frequently pair with ADA ramp or loading dock work on larger site projects, and we sequence everything to keep the schedule tight.
Anchor patterns, vibration isolation, sizing to loaded weight and equipment-installer coordination.
The pad has to support the loaded weight of the equipment (full of fluids, under service load) with a margin, and provide enough footprint for the anchor pattern plus access for maintenance. We size from the equipment cut sheet, not from generic tables.
We template the anchor pattern from the equipment cut sheet, build a wood or steel template that holds the bolts in exact position, and place that template in the form so the bolts are anchored during the pour at the right spacing and projection.
Some equipment requires it (especially generators, compressors). We use vibration isolation pads or specialized embedded systems per the equipment's spec sheet. Not every pad needs it; we follow what the equipment requires.
Exterior equipment pads need footings below the frost line in Boston, which is typically several feet. Interior pads on existing slabs can be much shallower or even tied into the existing floor depending on load. The engineering drives the depth.
Equipment installers typically wait for the pad to reach a specific cure strength before mounting the unit; for most pads that is within a few days of the pour. We give the installer the cure timeline so installation schedules without delay.
Client reviews
What Boston Operations Say About Their Equipment Pads
HVAC pad with anchor bolts that lined up exactly with the unit frame. The HVAC installer commented that it was the easiest install he had done that month. Templating is everything.
X. A.
Facility Manager, Boston
★★★★★
Generator pad engineered for the unit's vibration and weight. Three years of regular generator runs, zero crack development, zero shift. The engineering held.
Y. Y.
Industrial Operations Director, Cambridge
★★★★★
Transformer pad replacement during a planned outage. Coordinated the schedule tightly with the utility, pad cured and ready in the window. Power back on as scheduled. Real timing discipline.
Z. P2
Property Manager, Somerville
★★★★★
Multiple equipment pads across a plant expansion. Every cut sheet honored, every anchor template right, every pad finished to the elevation the equipment expected. No improvisation, no surprises.
Y. N2
Plant Engineer, Quincy
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