Metal Roofing, From Two Boilermakers

Standing seam versus exposed fastener

This is the choice that matters most, and the one homeowners are rarely given straight.

Exposed fastener

Screws go through the face of the panel, each one with a rubber washer to seal the hole. Cheaper to buy and quicker to install. The catch is that every one of those washers is a gasket sitting in the sun, and in the Fraser Valley the UV and the freeze and thaw work on them until they harden. Then the panel expands and contracts against a hardened washer and the hole starts to weep. On a house that means re-screwing the roof at some point. On a barn or a shop, where the budget is different and the building is not heated, it is often the right call.

Standing seam

The panels clip to the deck with concealed clips and the seams are folded over each other. There are no fasteners through the surface at all, so there are no gaskets to fail, and the clips let the panel move as it heats and cools instead of fighting it. It costs more up front, it will outlast two asphalt roofs, and on a house we will usually recommend it.

Thermal movement, which is where metal roofs go wrong

A long steel panel on a Fraser Valley roof can swing 40 degrees between a February night and an August afternoon, and it grows and shrinks measurably as it does. A panel fastened as though it were static will oil can, the seams will work loose, and the fastener holes will elongate.

So the clip spacing, the allowance at the eave and the ridge, and which seams are fixed versus floating are all calculated rather than eyeballed. That is the part our trade drilled into us: a pipe run without expansion allowance tears itself apart, and a roof is the same problem with a nicer view.

Where the water actually gets in on metal

• Penetrations. A pipe or a vent through a standing seam panel has to be flashed and boot detailed properly. It is the single most common metal leak we are called to.
• Transitions. Where metal meets a wall, a lower roof or a chimney. Same rules as any roof: lapped metal, not sealant.
• Valleys. A metal valley carries a lot of water fast. It needs to be sized for the roof above it and left open enough to shed debris.
• Galvanic corrosion. Copper flashing touching galvanised steel, or the wrong fastener in the wrong panel, and you get corrosion rings around every fixing within a few years. Material compatibility is not optional.
• Cut edges. A panel cut on site has raw steel at the cut. It gets treated, not left.

Snow, rain and noise

Metal sheds snow, which is why it suits Hope and the higher ground where snow load is a real structural concern. It also means snow comes off in one go, so above a door, a walkway or a gas meter we fit snow guards. That is a detail people only think about after the first slide.

On noise: a metal roof over a solid deck and underlayment in a heated house is not noticeably louder in rain. The drumming people remember is from an uninsulated barn roof fixed straight to purlins, which is a different assembly entirely.

Barns, shops and outbuildings

On the acreages around Yarrow, Greendale, Rosedale and out past Agassiz, most of the metal work is barns, shops and equipment sheds, and it is work we like. If you have a house and two outbuildings, quote them together. One mobilisation, one crane, one bin, and it is meaningfully cheaper than three separate visits.

What it costs

We do not publish a price for standing seam, and that is deliberate. Profile, pitch, the number of penetrations and how cut up the roof is move it more than floor area does, so any range wide enough to be honest is too wide to tell you anything. We measure it and give you a number. Exposed fastener agricultural metal on a barn or a shop is considerably less per square foot.

Divided across the service life the annual cost is usually lower than asphalt, which is the honest case for metal. It is still a bigger cheque on the day, and if you are selling in five years it may not be the right spend. We will say so.

Every quote carries the crane, the bin and the delivery as line items. The inspection is free and you get one clear price by email.

Warranty

Our 10 year labour warranty on the installation. The panels and the paint finish carry the manufacturer's own warranty, and on a quality PVDF finish that covers fade and chalk for a long time. We will show you the document rather than summarise it in our favour.