A self-storage roof is cheap to build and expensive to ignore, because every leak lands on a tenant's belongings and ends up in your claims folder. A long, light metal building has to meet the city's 60 psf snow design and 115 mph wind design. Price the facility by row. Rank the rows by leak history. Fix the worst row first and stage the rest across seasons. Send the site plan and the snow-load sheet, and we return a priced scope for each building.
The call: bid row by row, not site by site
A storage site is a set of repeating buildings. Buildings from the same kit tend to age together, but they do not leak together. The row that faces the prevailing wind, the row with the drift between two buildings and the row beside the office all age at different speeds.
A site-wide lump sum hides that. A row-by-row bid shows which buildings need work now and which can wait. It also lets the owner start with the row that has the most claims, then spread the rest across two or three summers. Cash flow improves, and the crew works in one area at a time, which keeps the lot open to tenants.
Row-by-row bidding also exposes the cheap fixes. Many leaks trace to a few missing closure strips, a cracked ridge cap or a corner trim that was never sealed. Fixing those across the whole site costs a fraction of a retrofit. We list them as a separate base line, so the owner can buy the cheap fixes now and choose whether the retrofit is needed at all.
What it costs: fasteners, laps and the retrofit alternate
On an exposed-fastener metal roof, the cost is in the screws. They back out as the panels expand and contract, the washers crack in the sun and the holes weep. Replacing every fastener with a larger one and new washers is a labor line. It is also the cheapest fix on the site.
If the panels are rusted or the laps are open, the bid moves to a retrofit: a new metal roof over the old one on a subframe, or panel replacement. A metal roof retrofit costs more up front and avoids tear-off and the open-roof risk. Break both options out. A third option, a coating over sound panels, costs less than either and works only when the metal is not rusted and the fasteners have been replaced first. The owner chooses with the difference in front of them.
What the code sheet says: 60 psf, 115 mph and 24 inches of frost
The city sheet adds severe weathering and a 24 inch frost line, and the statewide 2018 International Building Code applies. Light metal buildings are designed to those loads, and retrofit work adds weight, so the framing gets checked before any new layer. Purlin spacing, connection condition and any past sag all go on the checklist, and an engineer reviews anything that looks stressed. The check costs little and keeps a retrofit from becoming a repair job.
Wind matters on a long, low building with big flat walls. Edge trim, ridge caps and end-wall flashing hold or fail first when a big wind comes through. Price a heavier fastener pattern at the edges as its own line, and do not fold it into the base.
Where it fails first: ridge, laps and the drift between buildings
Ridge caps leak when the closure strips deteriorate. Laps leak when sealant dries out. Eave fasteners leak because that is where meltwater refreezes and the panel moves most. The gap between two buildings collects a drift that loads both eaves, and sliding snow can hit a driveway or a parked vehicle.
Snow guards belong above drive aisles and unit doors. Gutters and downspouts need to discharge away from the doors, where ice builds and tenants slip. A downspout that dumps onto the drive aisle makes a skating rink by December, and the fix is a short extension or a drain tile, priced as a line item. We price edge metal, coping and gutters as a line item, because ice at a roll-up door is a liability issue as much as a roof issue.
Alternates: standing seam, coatings and snow guards
A standing seam metal roofing panel hides its fasteners and lasts longer, but costs more than an exposed-fastener panel. A coating on a sound metal roof can seal laps and fasteners for less. Snow guards protect the drive aisles. Each is a bid alternate with a price.
We say which one we would buy and why, then let the owner pick. An owner with several sites, in Post Falls or out toward Rathdrum, can carry the alternates from one site to the next. Long spans and repeated bays work the same way on a warehouse or a flex industrial building, so the row-by-row method carries over.
Schedule and snow window: finish a row before it snows
Roofing on metal needs dry panels and calm days, and Post Falls sees about 59 inches of snow a year, so the window is summer and early autumn. A site with ten buildings takes a few seasons if the owner phases it. Book in winter so material and crew are set.
Tenants stay in their units. We stage material on a vacant row or a corner of the lot, keep drive aisles open and tell the manager which doors are blocked each day. Daily dry-in is not needed on metal retrofit, but open panels are tied down at the end of each shift.
Office buildings and manager units on a storage site have their own roofs, usually a different type from the storage rows. Bid them as separate lines. A leak in the office is the one the owner sees first, and a small membrane or shingle repair there is a quick win that builds confidence in the larger program. Keep it separate so it does not bury the storage rows in the bid.
Closeout: a row-by-row record
The owner gets a record for each building: photographs of ridge, laps and eaves, a list of fasteners and trim replaced, and a note on what remains. A fall visit checks gutters and downspouts before snow, and the photographs give the manager a dated record of the condition each row was left in, a record of which rows were done, which is the first thing an insurer asks for after a tenant claim. A spring visit looks for lifted panels, ice damage and any downspout that froze shut and sent meltwater across a drive aisle. The same schedule works for a site in Rathdrum and one in Coeur d'Alene.
Commercial Roofing Questions
Why do exposed-fastener roofs leak at the screws?
Panels expand and contract, which backs the screws out and cracks the washers. Larger screws and new washers fix it at low cost.
Should we retrofit or replace the panels?
Retrofit if the framing is sound and the old panels can carry a subframe. Replace if the panels are rusted through. We check both on the first walk. A retrofit adds weight on top of snow load, so the framing check comes first.
Do we need snow guards over drive aisles?
Yes, above aisles and unit doors. Sliding snow on a metal roof can hit a vehicle or a tenant.
Can tenants stay in place during the work?
Yes. We stage on a vacant row, keep aisles open and tell the manager which doors are blocked.
How do we rank which row goes first?
By leak history, tenant claims and the core or moisture results. The row with the most claims goes first.