Multifamily roofs get replaced one building at a time, and the number that matters is the cost per building after the first. A complex with a dozen buildings pays mobilization once, learns the details on building one, and finishes the rest faster. In Coeur d'Alene, ID every building on the site faces the same winter, with severe weathering on the city's sheet and ice barrier underlayment required at the eaves, and a good bid uses that sameness to hold the price down.
We write an apartment bid in phases, one building or one stair-tower group per phase, with a price for each and a discount for grouping. Residents get a notice before their building opens. The property manager gets a schedule, a punch list and a closing walk for each phase. The owner sees the full program and chooses how many buildings to take on in a season.
The Call: One Building at a Time
Phasing is the heart of the job. We walk the site with the property manager, mark which buildings leak, which have the oldest roofs, and which have residents with special needs, such as night-shift workers or families with infants. The first phase goes on the worst building. The second goes on the building next to it, which lets the crew reuse the same staging area.
Each building gets a dry-in at the end of every day and a final walk before the crew moves. Parking, trash enclosures and walkways are protected, and we agree with the manager on a laydown area that does not block resident parking. The notice to residents says what happens, when it starts and who to call. One phone number, answered, prevents many complaints. We also ask the manager to flag any resident who works nights, has a newborn at home or keeps a pet that reacts to noise, so the crew can start the loud work on the other side of the building first. A resident who got the notice and the phone number rarely needs to call the owner.
What It Costs: Pitch, Flat Sections and Fall Protection
Apartment buildings often mix roof types. A pitched shingle or metal roof covers most of the area, with flat sections over entries, balconies, stair towers and mechanical rooms. The mix drives the bid: each type is its own system and its own unit price. Steep sections add fall protection and slow the crew, and the labor line reflects.
The other lines are familiar. Tear-off or recover depends on the number of existing layers. Drainage on flat sections, gutters and downspouts on sloped ones, flashing at walls and chimneys, and ventilation in the attic space all have prices. Balcony and breezeway roofs are small but numerous, and a complex with many of them should see that count on the sheet. Each one needs a wall flashing, an edge and a drain path, and the hours add up faster than the square footage suggests. A bid that lumps them into the main roof price hides the line that most often turns into a change order.
Where It Fails First: Ice Dams, Valleys and Balcony Tie-Ins
Winter does the damage on multifamily roofs. Heat escapes from the units into the attic, melts the snow on the upper roof and sends water running to the cold eave, where it freezes into a dam. Water backs up behind the dam, slips under the shingles or the metal laps and appears as a stain on the ceiling of the top-floor unit. The City design sheet calls for ice barrier underlayment for exactly that reason.
Valleys, dormers and the joint where a balcony roof meets the main wall are the next weak points. They gather snow, and the melt concentrates at the seam. Buildings along the State Highway 41 growth corridor between Post Falls and Rathdrum sit in a place that sees about 59 inches of snow a year, so the pattern repeats from one building to the next. A roof that sheds well and vents well fails less often, and the attic is where the answer lies. Frost on the underside of the roof deck in February, damp insulation near the eave or rust on nail tips are all signs that warm, wet air is reaching the cold side of the roof, and each one is a cheap thing to look for before the bid.
What the Code Sheet Says: Underlayment, Ventilation and Insulation
Idaho enforces the 2018 International Building Code and 2018 International Energy Conservation Code statewide, and the city sheet requires ice barrier underlayment. For an apartment reroof, the code drives three things: an ice barrier at the eaves and in valleys, attic ventilation that matches the insulation, and insulation depth at the roof or the attic floor.
Balcony roofs and lower roofs below a taller wall collect drifts, and wet snow in those pockets is heavy. We check the framing and the drift locations before the bid is final. If the owner wants snow guards over walkways and entries, those are an alternate with a clear price.
Alternates: What the Owner Can Add Across the Site
Multifamily owners compare options against the long-term plan:
- Taking a second and third building in the same season
- Snow guards above walkways, entries and parking
- Heat cable at problem eaves and valleys
- Added attic ventilation and air sealing at the ceiling plane
- Gutter and downspout replacement with the roof
- A yearly roof visit across the complex
The ventilation and air sealing line stops ice dams at the source. Heat cable treats the symptom and costs power every winter. We list both and say which one we would pick: ventilation and air sealing first, cable only at the eaves the attic work cannot reach. A property manager who sees both prices side by side can answer an owner's question about why the cheaper line is not the better one.
Closeout: A Roof Record for Every Building
Each building leaves the project with its own record: layers, underlayment, ventilation, photos and warranty papers. The owner keeps those in a single file, which feeds the next capital plan. A roof capital plan spreads the buildings across years, and a commercial roof inspection sets the order. Real estate investors who buy a complex can start with a due diligence roof survey. Common areas and lobbies are planned the way a hotel lobby roof is, and a complex for older residents gets the same quiet-hours planning as a senior living roof. TPO serves the flat sections, and complexes in Post Falls and Rathdrum follow the same plan.
Commercial Roofing Questions
Do residents have to move out during the reroof?
No. We work one building at a time with notices posted ahead, a daily dry-in and protected walkways and parking.
What causes ice dams on an apartment roof?
Heat from the units melts snow from underneath, and the water refreezes at the cold eave. Ventilation, insulation and ice barrier underlayment fix the cause.
Is heat cable worth installing?
It treats the symptom and uses power all winter. Where the attic cannot be fixed, it helps. Where it can, ventilation is the better spend.
Can we do the whole complex in one summer?
Often, depending on the number of buildings and the crew. Larger complexes run over two seasons, starting with the worst roofs.
How do you handle balcony roofs?
As their own count on the bid. Each has a flashing at the wall and a drain or edge, and each leaks into the unit below if it fails.