Welding near you

Welders choose a process for the metal, its thickness and condition, and where the work happens. A good welder explains that choice rather than using whatever machine happens to be on the truck.

A mobile welder spares you from cutting out a railing set in concrete or towing a broken trailer, and most repairs to fixed railings, gates and equipment are done where they stand. A shop offers room to work, lifting equipment, tools for bending and cutting and shelter from the weather, which suits aluminum, fine TIG work, larger fabrication and anything that can be unbolted and brought in.

Welding works well on sound metal that has broken, cracked or come apart at a joint. It works poorly on metal that rust has thinned, because the weld has nothing solid to fuse to and the metal beside it keeps failing. A welder should probe the surrounding metal before quoting and say frankly when a section, or the whole piece, should be replaced instead.

Steel posts and beams that carry a floor, wall or roof are sized by an engineer, who also specifies the connections: the type and size of welds, bolts and bearing plates. Your municipality decides whether the work needs a building permit, and in Quebec the contractor doing the construction work needs a licence from the Régie du bâtiment du Québec that covers it. The welder's role is to build exactly what the drawings show, never to size steel by eye.

For structural and code-governed work, look for a company certified by the Canadian Welding Bureau under CSA W47.1, the standard for companies that fusion weld steel. Certification requires qualified welding supervisors, welding procedures reviewed and approved by the bureau, and welders tested for the processes and positions they use in production, and the bureau publishes a directory of certified companies. An engineer's drawings may call for a certified fabricator outright.

The Canadian Centre for Occupational Health and Safety (CCOHS) calls welding, cutting and soldering near flammable materials hot work, and its precautions translate directly to a house. Sparks and spatter land in dry leaves, siding, insulation or the gaps of a wood floor, and heat carried along a steel post or beam can ignite material hidden in a wall. CCOHS says a trained fire watcher should stay in the work area for at least 60 minutes after the work stops, and that some jobs need monitoring for up to 3 or more hours.

Much of the steel around a house is coated, and that matters once it's welded. CCOHS notes that the zinc on galvanized steel vaporizes into zinc oxide fume, which can cause metal fume fever, and lists paints, solvents, lead oxide primers, oils and rust inhibitors among the coatings that release harmful vapours or fumes. Its guidance is to remove coatings from the weld area without grinding them, since the dust may be toxic, and to capture fumes with local exhaust ventilation close to the source.