Sika Sarnafil Roofing Systems in Nampa, ID

A PVC roof is made of reinforced thermoplastic sheets that are joined by hot-air welding, which fuses the overlap into one piece. The welded seam is strong when the surface was clean and the temperature and speed were right. Flashings are made from the same family of materials, often prefabricated at corners and pipe penetrations, and are welded to the field sheet.

Because the system relies on welds, the inspection concentrates on them. A probe is run along each seam edge, and any entry point is marked and photographed. The flashings at penetrations, curbs and walls are examined for shrinkage, cracking at corners, and loose termination bars. Findings are entered against the section number so that a repair can be located without a second search.

Aging in a thermoplastic sheet is gradual. The surface may chalk, dirt may collect in low spots, and the sheet may lose some flexibility, especially at corners and where it bends over a curb. None of these is a failure alone. The report ranks them by what they threaten: a stiff sheet at a drain sump matters more than a dirty sheet in the middle of an open field.

Nampa's north quadrant plan names food-processing activity among the uses in that part of the city, and the city's economic profile lists food processing and agribusiness among its target sectors. Roofs on buildings like those, and on restaurants and grocery stores, receive exhaust discharges that can include fats, oils and cleaning chemicals. Exposure patterns follow the equipment, and the walk maps where the stains fall.

The remedy is practical. Grease traps on exhaust fans are checked and cleaned, splash pads are placed beneath discharge points, and a membrane section that has been softened or stained is tested before it is trusted. For a restaurant roof, the record includes the position of every exhaust fan and the condition of the membrane beneath and downwind of it.

Where equipment is added or moved after the roof is installed, the exposure map changes. A new exhaust fan on the upwind side puts discharge onto sections that were clean before, so the visit log records equipment changes by date and the next inspection checks the sections downwind of them.

Thermoplastic sheets do not always tolerate contact with asphalt-based materials, so a recover or repair over an older built-up or modified bitumen roof needs a separation layer. Mixing materials without that layer can cause the new membrane to soften and lose strength at the contact point, sometimes months after installation.

Before any detail is specified, we identify the layers on the roof by core cut and photograph them. Where an old asphalt surface sits beneath, the specification names the separation layer, the insulation or cover board, and the attachment method. A recover is possible only when the moisture evidence supports it, and the plan states what was found so the choice can be reviewed later.

Insulation and cover board selection matter as well. A cover board between old insulation and a new thermoplastic sheet adds a flat, firm base for adhesion, and it protects the membrane from fasteners that may back out of an older deck. The thickness and type are written into the scope, and the closeout photographs show the board before the membrane covers it.

Most thermoplastic roofs show their first leaks at details: pipe boots, drain flashings, curb corners and skylight perimeters. A prefabricated boot is welded to the field sheet and checked with a probe. A curb that has been raised or moved is reflashed with a new corner piece, not patched over the old one. A skylight or penetration flashing gets a photograph before and after, taken from the same position.

Where hot work or welding is limited by wind or low temperature, the detail is staged. Water is stopped with a temporary measure, and the permanent weld is made when the surface is clean and the conditions are right. The work order notes which measure is temporary so it cannot be mistaken for a finished repair.

Drains deserve a separate look. A sump that has settled, a clamping ring with loose bolts, or a strainer that has been removed can each let water run beneath the flashing. The repair resets the ring, replaces the gasket where needed, and welds a new flashing collar to the field sheet. The test is a water run at the drain, observed from below where access allows.

The valley sees over 75% of its annual precipitation between November and May, and the city's winter design temperature is 10 degrees Fahrenheit. Thermoplastic sheets stiffen in cold and move at seams, so the autumn walk checks that welds are tight and drains are clear. Spring brings a second walk to check for lifted seams and damaged flashing.

Along Karcher Road, where the north quadrant plan lists an I-84 interchange and describes industrial tracts, and across North Nampa, buildings with process exhaust get a closer look at the membrane surrounding each stack. The file includes a photograph of the stain pattern, so future visits can tell whether it is spreading.

The warranty that comes with a roof has its own terms, and our role is to keep the file that supports them: installation evidence, visit logs, repair photographs and test results. A warranty file built that way helps whether the claim is large or small. Owners weighing a thermoplastic roof against another can compare it with Duro-Last or Holcim Elevate systems in the same inspection record.

Why is a PVC roof used where kitchen exhaust lands on it?

The sheet is made to resist many fats and oils, and its welded seams stay closed under that exposure. Fan traps and splash pads still reduce what reaches the surface.

Can a thermoplastic roof go over an old asphalt roof?

Only with a separation layer, and only when the insulation below is dry. Direct contact with asphalt can soften the new sheet, so the specification names the layer that prevents it.

What is a probe test?

A small blunt tool is drawn along the edge of a weld. If it slips into the seam, the weld is open and gets marked, photographed and repaired by re-welding.

Do stained areas near exhaust fans mean the roof is failing?

Staining shows where discharge falls. We test the membrane there for softness, check the seams, and decide whether it needs cleaning, protection or a section replaced.

Is welding possible in winter?

On workable days with a clean, dry surface, yes. In deep cold we use a temporary seal and return for the permanent weld when conditions allow.