Commercial Roofing in Midland Boulevard Corridor, Nampa, ID

A tie-in is where a new roof joins an existing one: an addition against an older wall, a new bay beside an old bay, or a remodel that raises part of the roof. The two roofs may be different heights, different ages and different systems, and water that runs off the upper one lands on the lower. The tie-in has to handle that water, allow the two structures to move slightly against each other, and keep the membranes from touching dissimilar materials.

We inspect each junction for four things: the termination at the wall, the flashing lapped over the lower roof, the wear surface under any runoff, and the sealant at the top edge. A lower roof under a high wall often shows scuffing, ponding or a thinned membrane where runoff concentrates. A wear strip, a splash pad or a diverter fixes that. The photographs show each stage, and the repair limit is written in terms of the junction and the sections on either side of it.

Expansion joints between roof areas need their own attention. A joint that has been painted over, filled with the wrong material or covered by a membrane without slack will split with the first season of movement.

Infill buildings often share a wall or a lot line with a neighbor. Water that leaves one roof can land on another, and a blocked scupper on a neighboring roof can send water into a wall. When a leak appears near a shared wall, the first step is to establish which roof, which flashing and which owner.

The record handles this by photographing both sides of the wall where access allows, marking the flashing heights and noting where each roof drains. If drainage crosses a boundary, the file says so, and the owner can raise it with the neighbor on the basis of dated photographs. We do not alter a neighbor's roof; we document the condition we can see from the owner's side and the access we have.

Where two roofs on the same owner's property share a drain or a gutter, the sizing is checked against the combined area. Undersized drains are a common cause of ponding and overflow, and a drain and scupper upgrade is priced as its own item.

A building in an area with infill opportunities may have been altered several times. A walk finds the evidence: patches in different materials, abandoned penetrations, old curbs, different insulation thicknesses and changes of deck. Each alteration is a detail that someone made at a specific time, often without a drawing. We number the sections by alteration and rate each separately, so the oldest and the newest parts do not hide behind one overall opinion.

We do not assume a building's age, roof type or condition from its address or its place in the plan. The cores and the walk establish them. A roof with three layers of membrane, for instance, is not a candidate for another recover, and the record states that plainly. A roof with a single layer and dry insulation may take a recover, and the file shows the core results that support it.

Infill and remodel work changes what sits on a roof. A new kitchen exhaust, a relocated rooftop unit, a skylight added to brighten an interior or a vent for a new use each cut the roof. The risk is that the work is done by a trade that does not roof, with the opening closed by sealant and a hope. We ask for the remodel scope before it begins, so the roof detail can be specified and the work sequenced.

A skylight or penetration flashing detail uses the roof membrane itself where possible: a prefabricated boot, a welded or adhered flashing, a curb with a counterflashing. Each new penetration is entered in the penetration log with its date, the trade and a photograph of the flashing before it is covered. Without the log, a leak search years later has to treat every opening as a suspect.

If the remodel adds weight to the roof, such as new equipment, the structure is checked against the original design loads. Nampa's 25-pound minimum uniform roof load is a design reference, not a statement about any particular building, so the drawings or an engineer settle it.

On buildings with several roof areas of different ages, the choice is rarely all or nothing. A replacement may be phased: the worst section this year, the next in a later season, with the condition record deciding the order. Phasing spreads cost and keeps the building in use, but it also creates more junctions, and each new junction has to be detailed with care. The scope lists the phases, the junctions between them and the temporary details that hold until the next phase.

Repairs on the sections left for later are priced separately and carry their own limits, so an owner can see the full cost of waiting. A section that is repaired now and replaced in two seasons is not the same as one that is replaced now, and the file shows both numbers without a recommendation dressed up as a fact.

Under the local criteria, ground snow counts as 20 pounds, roof design load starts at 25, and frost reaches down 24 inches. Most of the valley's precipitation falls between November and May, and winter inversions can make valley locations colder than the airport readings. Junctions, drains and low areas are the places where a wet season shows its effect. So the fall walk concentrates on tie-ins and drains, with photographs taken before the first storm.

The spring walk repeats the same positions. A junction that has opened, a sealant bead that has cracked or a drain that ran slowly will show in a side-by-side comparison. That comparison is the basis of the repair priority and the maintenance budget.

Owners in the west quadrant can hold more than one property. The Downtown Village and the Caldwell Boulevard corridor appear in the same plan, yet a roof in each is filed and rated separately.

What fails first at a tie-in?

The top termination or the flashing over the lower roof, where movement and runoff concentrate. A photo of the junction at each visit shows whether it is opening.

Who is responsible when water crosses a lot line?

The file records what is visible from the owner's side with dated photographs. Responsibility between neighbors is a matter for the owners and their documents.

Why number sections by alteration?

Parts added at different times have different materials and different weaknesses. Separate numbers keep the older and newer parts from sharing one rating.

Can a third layer of roofing be added?

A roof that already carries multiple membranes generally goes to tear-off, with cores showing the layers. The record states the reason.

What does an expansion joint need?

Slack in the membrane over the joint, the right filler and no paint or sealant bridging the gap. A joint that cannot move splits within a season.