U.S. President Donald Trump has increased tariffs on steel and aluminum imports from 25 per cent to 50 per cent.

The presidential proclamation went into force at 12:01 a.m. EDT Wednesday. In that document, Trump said the new rate would better counter “foreign countries that continue to offload low-priced, excess steel and aluminum,” undercutting the U.S. market.

Ottawa called the additional levies “unlawful and unjustified.” About a quarter of all steel used in the United States is imported and Canada is its largest supplier.

Here’s what happened throughout the day:

6 p.m. EDT: Canadian businesses who rely on steel and aluminum grappling with tariff hike

For the Laplante family, steel has been their business for close to a century.

As manufacturers of steel roofs and siding, as well as a supplier of products such as steel coils, screws, and sheet metal for HVAC and construction companies, U.S. President Donald Trump’s doubling of tariffs on steel and aluminum is impacting their business directly.

“We can’t swallow a 50 per cent increase, and the customers in the U.S. won’t pay 50 per cent more for the same product,” said Ideal Roofing CEO Claude Laplante. “We’ve been working hard at developing an American market for the last 50 years… We’ve had trucks going into the U.S. every week, twice a week, three times a week, and now that’s all going to stop.” The company tries to source as much as they can domestically, though with more than 300 Canadian workers on the payroll and sales decreasing, the worry is there.

“We’ve always been… a proud supporter of Canadian steel, buying Canadian steel, employing, keeping the jobs in Canada. That’s going to be deeply affected,” said his son, Philippe Laplante, the company’s vice-president of sales and marketing.

Brewers across the country are also feeling crushed, by the rising cost of aluminum cans.

Among them, Ottawa’s Dominion City Brewing Co. After stockpiling more affordable cans before the tariffs took hold, co-owner Josh McJannett says the cost of supplies is gradually increasing. “The fear is that, you know, come fall, when a lot of the stores of inventory that our own suppliers had stocked up on, run out we’re going to be taking significant price increases on a lot of these things.”

“There’s a lot of upward pressure for a small business like ours,” he said. “The things we use to make our product are just all kind of getting more expensive.”

McJannett said while they’ve been trying to absorb the costs rather than pass them on to consumers, but they still need to ensure business sustainability. He’d like to see governments adjust policies that could offer some relief, such as making permanent the reduced rates of excise duty on beer brewed by domestic brewers.

“Our urgent call is while all of these things are happening that are accelerating our costs, I think that it’s all the more important that we are grabbing those levers that we can control. And I think some of those calls around excise tax, other things we can do that can make our businesses more competitive, those are the places to start.”