Ductwork Services in York

Gravity furnace duct conversions remain one of the most common ductwork projects across York, particularly in the pre-war housing stock of Weston and Mount Dennis. Original gravity systems used oversized round trunk lines — often 14 to 18 inches in diameter — designed for natural convection rather than forced air. When homeowners converted to forced-air furnaces decades ago, many contractors simply connected the new furnace to the existing oversized trunks without properly resizing branch runs or adding adequate return air paths. A full gravity-to-modern duct conversion in York typically costs $8,000 to $14,000 and involves replacing the trunk line, installing properly sized 6-inch and 7-inch branch runs, adding return air ducts to each bedroom, and sealing the entire system. This work dramatically improves comfort and can reduce heating costs by 25 to 35 percent.

Moisture intrusion is a serious concern for ductwork in York homes near the Humber River floodplain, especially in Weston and Rockcliffe-Smythe. Basements in these neighbourhoods frequently experience elevated humidity levels, and uninsulated metal ductwork running through these damp environments develops condensation that leads to interior rust and mould colonization. Homeowners should budget $2,500 to $5,000 for duct insulation wrapping on exposed basement runs, and $1,200 to $2,500 for mould remediation inside contaminated duct sections. Flex duct connections in these areas are particularly vulnerable — moisture wicks into the fibreglass insulation layer and creates hidden mould problems. Replacing flex connections with sealed rigid metal and adding vapour barrier insulation is essential for homes within the floodplain zone.

The 1940s and 1950s bungalows found throughout Keelesdale and Lambton present a specific ductwork challenge: many have floor-embedded duct runs cast directly into the concrete slab. These in-slab ducts collect decades of dust, moisture, and debris, and they cannot be cleaned or sealed using conventional methods. When these ducts deteriorate, the only practical solution is to abandon the in-floor system entirely and install a new overhead duct network through the basement ceiling, routing supplies up through interior walls. This conversion costs $10,000 to $16,000 for a typical three-bedroom bungalow and requires careful planning to minimize ceiling height loss in the basement. Some Keelesdale homeowners opt to combine this work with a basement finishing project to offset the disruption.

Return air deficiency is endemic in York's older homes. Many houses in Silverthorn and Mount Dennis were built with a single central return air grille — often located in a hallway — serving the entire home. Modern HVAC standards call for return air in every bedroom and main living area. Adding dedicated return air runs typically costs $800 to $1,500 per room and involves cutting into walls, running new ductwork back to the furnace plenum, and installing transfer grilles or jump ducts where full return runs are impractical. Without adequate return air, bedrooms with closed doors become pressurized, forcing conditioned air out through gaps and pulling unconditioned air through the building envelope, which increases energy costs significantly.

Asbestos-containing duct tape, sealant, and insulation are commonly found in York homes built before 1980. The white cloth tape used to seal joints on galvanized ductwork in Weston and Rockcliffe-Smythe houses from the 1940s through 1960s frequently contains chrysotile asbestos. Before any duct modification or replacement work, a professional asbestos assessment is recommended, costing $300 to $600. If asbestos materials are confirmed, abatement by a licensed contractor adds $2,000 to $5,000 to the project depending on the extent of contaminated materials. Ontario Regulation 278/05 governs asbestos handling, and homeowners should never attempt to remove suspected asbestos duct materials themselves.

Many York homeowners in Silverthorn and Keelesdale are converting single-storey homes into two-storey dwellings or adding second-floor additions, which requires extending ductwork to the new upper level. Running new supply and return ducts to a second storey costs $4,000 to $8,000 depending on the number of rooms and the routing complexity. The most effective approach uses a dedicated second-floor trunk line with individual branch runs rather than simply extending existing first-floor branches upward. In these older homes, interior wall cavities are often too narrow for standard rectangular duct, so contractors frequently use 2.25-by-12-inch slim duct or flexible duct routed through closets and soffits to reach upper-floor registers without extensive wall demolition.