A spec that names GAF gives the bid two jobs: price what the maker requires and price what the city requires, then show where they overlap. GAF's commercial line covers single-ply membranes, led by TPO, along with modified bitumen and built-up components. The warranty paperwork and the maker's installation details set the minimum. In Coeur d'Alene, ID the city's 60 psf snow and 115 mph wind designs can push the roof past the maker's minimum.
We price the maker's system and the snow-country additions on separate lines, so the owner decides what stays in.
The Call: What a GAF Spec Means for the Bid
A named system tells us the membrane type, the insulation and cover board, the attachment method and the warranty the owner expects. It does not tell us the drift pockets, the drain count or the edge metal, which come from the building and the site. Our first step is to read the spec against the plans and mark the gaps.
We then build the bid in three parts. The base scope follows the spec as written. The alternates cover the snow-country items the spec is silent on. The change-order triggers list the surprises we can predict, such as wet insulation found at tear-off, with unit prices attached. A GC comparing bids will see the same structure and can compare line to line.
Where an existing GAF roof is under warranty, the first call is to the warranty paper, not the roof, because the terms decide who may touch it. Many terms ask the owner to report leaks promptly and to use an approved repairer. We read the terms, document the leak and help the owner notify the right party, then fix what the warranty allows us to fix.
What the Maker Offers: Single-Ply and Layered Systems
On the single-ply side, the center of the line is TPO, a heat-welded white or tan membrane installed mechanically attached, fully adhered or ballasted. On the layered side, the maker's modified bitumen and built-up components suit roofs that want redundancy and a granule or gravel surface, the same reasoning behind our modified bitumen and built-up roofing installs.
Each system comes with insulation, cover board, fasteners, adhesives and flashing accessories sold to go with it. The warranty depends on using the approved set. We install what the spec calls for and flag any substitution before it reaches the roof, because a mismatched accessory can cost a warranty.
Insulation and cover board matter as much as the sheet. A rigid polyiso board with a cover board over it gives the membrane a flat, stable bed, and it protects against hail and foot traffic. We show the board as a priced line in the insulation and cover board scope, with thickness set by the energy code and the snow load.
What It Costs: Warranty Tier and the Lines Under It
Maker warranties come in tiers, and the tier changes the price. A longer or more inclusive term usually asks for a stricter installation standard, more inspections and sometimes thicker membrane or added attachment. The owner should know what each tier adds before choosing it. We list the tiers the maker offers for the system and the cost step between them.
Beneath the warranty, the same lines move every bid: insulation thickness, attachment method, edge metal, drains and tear-off. Edge metal and perimeter fastening are where the city wind number shows up. One hard windstorm is reason enough not to price the perimeter at the minimum. The warranty and the wind rating are different documents, and we make sure both are met.
Lead time is a cost too. Membrane, insulation and accessories ship from different places, and a late shipment idles a crew. We confirm delivery dates before we release the start, and we stage material on the roof or in a protected laydown so the first dry week is not lost. A short material delay in September can push a job into the snow, so we flag that risk in the bid.
What the City Sheet Says: The Overlay on the Maker's Details
A maker's standard detail is written for a wide range of climates, and the city rates this one as severe. Ice barrier at the eaves, heavier edge fastening and drift-pocket drainage often sit on top of the standard detail.
City Building Services checks submittals against its sheet under the statewide 2018 International Building Code. We prepare the submittal with the system data, the wind uplift rating and the fastening pattern, so the permit does not hold up the start date. Where the maker and the city differ, the stricter requirement governs.
Idaho's statewide energy code adds its own requirement for insulation value, and the roof assembly has to satisfy it along with the structural numbers. We show the insulation thickness that meets the code, the thickness the spec calls for, and the difference if there is one, so the GC sees the choice before the order is placed.
Where It Gets Specified: Warehouses, Retail and Institutions
Specs naming GAF show up on the same kinds of buildings as any major maker. Tilt-up warehouses at Riverbend Commerce Park in Post Falls, retail like the Village at Riverstone and institutional work such as the 18-school Coeur d'Alene School District can all produce roof bids that name a maker. Owners weigh makers by warranty term and support, and the same plans can be priced against Carlisle SynTec, Johns Manville or Versico systems for comparison.
For roofs we maintain after installation, our preventive maintenance visits keep the records the maker's warranty asks for: inspection dates, repair logs and photographs. That file matters when a claim arrives.
Closeout: Inspection, Punch List and Paperwork
Closeout follows a short list. The maker's inspection, when the warranty requires one. Our own walk with the GC. A punch list closed before the crew leaves. The warranty application and the as-built notes submitted on time. We keep photographs of every flashing and seam, because a warranty review asks for them, and we label each with its location on the roof plan.
Timing matters in this climate. A roof closed in October is warranted before the first snow, and a roof that waits until spring is exposed through the winter. We schedule to finish ahead of the freeze, and we price a short extension if the owner wants to wait.
After closeout the roof goes into a maintenance rhythm: a fall walk before the snow, a spring walk after the melt and a look after any severe storm. The record of those visits is what a warranty reviewer asks for, and it is cheaper to build it as we go than to reconstruct it after a leak.
Commercial Roofing Questions
Do you install GAF systems?
We install and repair roofs of the types the maker's line covers and follow the published details for the system named in the spec. Send us the spec and we price it as written.
What if the spec says GAF or equal?
We price the named system as base and show an equal as an alternate, with the warranty difference listed. The owner picks.
Does the warranty cover wind and snow damage?
Many warranties set wind limits and exclude storms. Send us the warranty document and we read the terms before the bid.
Can a GAF roof be repaired by another roofer?
Some warranties require the installer or an approved applicator. We read the terms before touching the roof.
How long does a spec review take?
Usually a few days, once we have the plans, the spec section and the snow-load sheet.