The Monument
Scope
Single-Ply (PVC) Restoration
Location / Area
Rapid City, SD · 193,018 sf
Site parameters
- Building type
- Civic event venue
- Venues restored
- 3
- Roof levels
- 6, from 15 ft to 100 ft+
- Existing system
- Mechanically fastened reinforced PVC, 20+ yrs
- Roof area
- 193,018 sf
- Completed
- 2024
GacoFlex single-ply restoration system
- Manufacturer
- Gaco / Holcim
- Topcoat
- S-2000 silicone
- Primer
- E5320 epoxy
- Applied at
- 2.5 gal / 100 sf
- Wet film
- 40 mil
- Cured film
- 38 mil
- Roof area
- 193,018 sf
- Warranty
- 20 yr
Delivered in 2 phases
- Rushmore Hall
- 83,332 sf
- Fine Arts Theatre
- 38,708 sf
122,040 sf
- Barnett Fieldhouse
- 70,978 sf
70,978 sf
Inspection and testing
A fluid-applied system is bonded to the roof it covers, which makes the old membrane the substrate. Nothing was priced or promised until that substrate had been proven sound. Before Phase 2 was quoted, A-1 and a Holcim representative inspected and tested the Barnett Fieldhouse roofs together on 23 August 2023.
- Moisture, isolated and repairable
- Across the Barnett Fieldhouse roofs, a moisture meter and core samples traced roughly 2,800 sq ft of saturation to isolated ponding areas around unrepaired hail penetrations. The insulation underneath was intact with some moisture present — a repair, not a tear-off.
- Adhesion, passing
- Several adhesion tests came back passing, confirming that once the field was cleaned and primed the new fluid membrane and the existing PVC would fuse into a single system rather than sit on top of one another.
- Hail, quantified
- Impact damage was estimated at one hit per 250 sq ft across the fields, previously patched with elastomeric products as a temporary measure. Quantifying it up front is what let the repair scope be priced instead of discovered.
- Permission to warrant
- The pre-inspection report, test results, and pre-installation notices went to Holcim's technical department for review. On 13 October 2023 Holcim issued an official letter of intent to warrant the twenty-year system.
What changed
On arrival
- A 20-plus-year-old PVC single-ply membrane, oxidized and turning brittle
- Cracked and shattered flashing components throughout
- Over five miles of failing seams
- Hail damage at roughly one hit per 250 sq ft, temporarily patched
- Scattered wet insulation board beneath the membrane
- Phantom leaks that were difficult to trace to a source
- An expired manufacturer warranty
- A traditional replacement would have meant a full tear-off
On completion
- Flashings and seams repaired and reinforced across all three venues
- Hail damage rebuilt with the three-course reinforcement process
- Wet insulation removed and replaced where cores found it
- A seamless 38 mil silicone membrane over the entire 193,018 sq ft
- A 20-year manufacturer NDL warranty covering labor and material
- Roughly 30% less than a traditional overlay would have cost
- Renewable in place — washed and recoated to reset the cycle
- No tear-off, and nothing sent to the landfill
What the job included
- Pre-installation inspection, moisture cores, and adhesion testing
- Hail and flashing repair by the three-course process
- Wet insulation removed and replaced where found
- Full wash, prime, and seam detail ahead of topcoat
- S-2000 silicone spray-applied to 38 mil dry film
- Factory inspection and a 20-year NDL warranty
PRJ-02 scope of work
Work performed
Repair
Hail splits and shattered flashings identified, cleaned, stripped of loose material, and rebuilt with polyester mesh embedded between two wet coats of Gaco fluid.
Moisture removal
Wet insulation and underlayment removed and replaced where the cores found it, so no saturated material was sealed in beneath the new membrane.
Clean
Each section blown free of debris, then washed with concentrated GacoWash, mechanical agitation, and high-pressure surface washers once the repairs had fully cured.
Prime
GacoFlex E5320, a two-component water-based epoxy, spray-applied across the field at 250 sq ft per gallon to fuse the new system to the old membrane.
Detail
Every seam, sidelap, corner, boot, and patch reinforced with SF2000 fibered silicone or GacoPatch at 70 linear feet per gallon, before any topcoat went down.
Topcoat
S-2000 100% silicone spray-applied at 2.5 gallons per 100 sq ft through airless rigs holding 5,000 psi at the tip, to a 40 mil wet film.
Assembly, substrate to membrane
- 1
Substrate
The existing insulation board and mechanically fastened reinforced PVC membrane, left in place, repaired, and washed. Nothing came off the deck.
- 2
Primer
GacoFlex E5320 two-component water-based epoxy across every joining surface, bonding the restoration to the original membrane.
- 3
Reinforcement
SF2000 fibered silicone, GacoPatch, or U91 with 66S polyester mesh at every seam, lap, termination, and repaired area — the step that turns a seamed roof into a seamless foundation.
- 4
Membrane
GacoFlex S-2000, a solvent-free 100% silicone coating, sprayed to 38 mil dry film across all 193,018 sq ft. Monolithic, UV-stable, and recoatable without removal.
What made this one hard
Nearly 200,000 sq ft over a live civic venue is not a bigger version of a small roof. Six conditions on this job would each have cost time or spec compliance if they had been met with a standard crew and a standard plan.
Six roof levels, 15 feet to over 100
The venue's roofs step across six levels. Every one of them changed the fall-protection plan, the staging footprint, and how far material had to travel to reach the gun. A-1 added safety training and equipment for the heights, brought in additional production equipment, and assigned a dedicated ground crew to nothing but keeping the rigs fed and running.
No room for product or labor overrun
Across a field this size, a few extra mils compounds into thousands of gallons, and a shortfall costs the warranty. A-1 put dedicated quality-control personnel on continuous wet- and dry-film gauging rather than checking the work at the end of it.
Oxidation fighting the primer
Two decades of weather had left the PVC heavily oxidized, and a conventional wash was not leaving a surface the epoxy primer could bite into. A-1 added abrasive mechanical scrubbers ahead of the high-pressure washers to cut through the oxidized layer.
The building could not supply the water
The added cleaning outran the facility's water service. A-1 sourced municipal water and a delivery system to hold the volume and pressure the wash process required, rather than slowing the wash to match the tap.
Holding spec without wearing the crew out
Maintaining a 40 mil wet film over acres of roof punishes an applicator, and a tired applicator drifts out of spec. A-1 ran a SprayWorks Spray Bot, an automated robotic applicator, to carry the open field at a consistent rate.
A presidential rally, mid-project
A Donald J. Trump rally at the venue raised security requirements sharply and cost the job production time. A-1 planned staging, access, and equipment placement directly with facility personnel and the Secret Service, met the security requirements, and kept the production timeline on track.
Verification on completion
- Wet film thickness
- Gauged continuously during application
- Dry film thickness
- Verified with MIL-spec reticle gauges
- Defect sweep
- Full roof walked in a grid pattern
- Factory inspection
- Holcim technical personnel, all details and terminations
- Thickness cores
- Sampled and recorded at random every 2,000 sf
- Warranty issued
- 20 yr NDL, labor and material
Specifications referenced
- Gaco SP-S2000-38-20
- GacoFlex S-2000 PDS
- GacoFlex E5320 PDS
- GacoFlex SF2000 PDS
- GacoFlex U91 + 66S PDS