Lumber, building materials, expert advice, and full-service project support — everything under one roof, from a team that knows your name.
From framing lumber to finish trim — explore our full range of building supplies and home improvement products.
From planning to completion, our team helps you build smarter, faster, and on budget.
We review your blueprints and prepare a complete, itemized materials list with accurate pricing — no guesswork, no budget surprises.
Get an estimate
Visualize your dream deck before a single board is cut. Customize size, shape, colour, levels, stairs and railings with full material costing.
Start designing
Free contractor delivery in the Kapuskasing area. Residential deliveries also available — we bring it right to where you need it.
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Bring in any sample and we'll match it exactly. Our paint-matching service takes the guesswork out of your next painting project.
Explore paint
From cabinetry to countertops and fixtures, our team helps you plan a functional, beautiful kitchen or bathroom renovation.
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Need a spare house key, a new padlock key, or a copy for the cottage? We cut keys in-store while you wait — fast, accurate, and affordable.
Visit us in-store
We're not a box store — we're the local team that knows your project, your timeline, and your name. Our 10,000 sq. ft. store, covered warehouse, and full-service lumberyard mean you get everything in one trip.
As Castle Building Centres members since 1974, we deliver competitive pricing backed by a national network — while remaining independently owned and community-driven.
Framing lumber, plywood, decking, fencing, roofing, drywall, insulation, hardware and more — stocked in our covered warehouse and outdoor yard.
Our 15-member bilingual team brings hands-on construction experience and building code knowledge to every single customer interaction.
Active members of the Northern Corridor Chamber of Commerce, CFIB, LBMAO, and the Canadian Retail Hardware Association. This is our home, too.
Whether you're framing a house or fixing a fence, we have the materials, expertise, and service to back you up.
Tackling a renovation, building a deck, or need the right hardware? We'll help you plan, pick materials, and stay on budget.
We understand job-site timelines. Count on us for accurate take-offs, reliable stock, fast delivery, and competitive pricing.
✦ Free 3D Design Service
Our complimentary 3D deck design service lets you visualize the finished product, experiment with materials and colours, and get an accurate materials estimate — all before breaking ground.
“Planned my entire garage build through Knowles. They did the take-off from my blueprints, delivered every stick of lumber on schedule, and the price beat the big box stores in Timmins. Couldn't ask for more.”
“20 years running crews in Northern Ontario. Knowles is the only supplier that consistently gets my orders right the first time. Their take-off service alone saves me hours every week. That reliability is why I keep coming back.”
“First time staining a cedar deck and I had no idea where to start. The team spent 20 minutes with me picking the right product and walking through application. Turned out perfect. Love supporting local.”
Proudly serving Kapuskasing, Smooth Rock Falls, Hearst, Moonbeam, Fauquier, and surrounding communities across Northern Ontario.
Whether you need a complete materials list from blueprints or a quick price on lumber, our team will get back to you within one business day.
Fill in the details below and we'll prepare your estimate.
Visit us in Kapuskasing or Smooth Rock Falls, give us a call, or request a quote online. We're here to help — and we always have been.
