Fast facts
| Trade code | 451A |
|---|---|
| Sector | Construction |
| Classification | Voluntary trade |
| Certifying exam | Required (O. Reg. 876/21, s. 3) |
| Apprentice to journeyperson ratio | Subject to a ratio (O. Reg. 876/21, s. 4) |
| Red Seal trade | Yes |
| Active apprentices in Ontario | 1,169 (reported in Ontario's apprenticeship dataset) |
| Approved sponsors | 37 |
| Certifying body | Skilled Trades Ontario |
Last verified August 20, 2026 against the sources listed below.
What does a drywall, acoustic and lathing applicator do?
A Drywall, Acoustic and Lathing Applicator erects exterior structural steel studs and sheathing, shaft wall systems, installs and finishes lath and drywall, partition walls and furring, ceiling systems and access flooring types as well as applies thermal and sound insulation.
Skilled Trades Ontario describes the work of this trade as follows:
- reads, interprets, and applies blueprints and specifications for job layout
- erects exterior structural steels studs and sheathing
- erects light gauge residential steel studs, sheathing and demountable partitions
- applies thermal insulation, sound insulation, and fire stopping
- installs partition walls and furring and shaft wall systems
- installs lath, drywall, moulded and cast forms and ceiling systems
How long is the drywall, acoustic and lathing applicator apprenticeship?
| Total training hours | 5,400 (about 3 years) |
|---|---|
| On the job | 4,800 hours |
| In school | 600 hours |
| In-school levels | 2 |
These hours are set by the Registrar of Skilled Trades Ontario under section 14 of the Building Opportunities in the Skilled Trades Act, 2021.
What do you study in school for the 451A?
The in-school portion covers, but is not limited to:
- trade knowledge and safety orientation
- trade calculations
- plan reading
- partitions and curtain walls
- suspended ceiling systems
- residential steel-stud construction
- thermal and sound theory and application
- geometry theory and application
- metal cutting and welding
- drywall partitions and ceilings
- raised-access flooring
Is drywall, acoustic and lathing applicator a compulsory trade in Ontario?
No. Drywall, Acoustic and Lathing Applicator is a prescribed trade under section 1 of O. Reg. 876/21, but it is not on the compulsory list in section 2. That means you can legally work in this trade in Ontario without holding a Certificate of Qualification. Certification is voluntary and serves as formal proof of competency to employers and clients.
Voluntary classification only covers certification under the Building Opportunities in the Skilled Trades Act. Specific work within the trade can still require separate licences or permits under other Ontario statutes, so confirm the rules for the actual work being done. The 23 trades where certification is mandatory are on the compulsory trades list.
How do you become a drywall, acoustic and lathing applicator in Ontario?
The apprenticeship pathway for this trade is administered by Skilled Trades Ontario under section 14 of the Building Opportunities in the Skilled Trades Act, 2021:
- Find a sponsor and register a training agreement. An employer or union sponsor takes you on and the training agreement is registered with the ministry.
- Complete the on the job and in school training. The skills are set out in the trade's Apprenticeship Training Standard, signed off by your sponsor as you demonstrate them, alongside levels of in school theory at a training delivery agent.
- Receive your Certificate of Apprenticeship. Skilled Trades Ontario issues it when the program is complete.
- Pass the certifying exam. This trade has a certifying exam under O. Reg. 876/21, s. 3. Passing it earns the Certificate of Qualification, the voluntary proof of qualification for this trade.
The exact training standard, current curriculum and program details are on the Skilled Trades Ontario page for Drywall, Acoustic and Lathing Applicator. On the job hour requirements vary by trade and are not published on this page yet; confirm them in the training standard before signing an agreement.
Is there an apprentice to journeyperson ratio for the 451A?
Yes. Drywall, Acoustic and Lathing Applicator is one of the 33 trades that section 4 of O. Reg. 876/21 makes subject to an apprentice to journeyperson ratio. The regulation establishes that a ratio applies, but the numeric ratio itself is not stated in section 4. Confirm the current ratio with Skilled Trades Ontario before registering an additional apprentice, because it limits how many apprentices a sponsor may train at once.
Is the 451A a Red Seal trade?
Yes. Drywall, Acoustic and Lathing Applicator participates in the Interprovincial Red Seal Program, the national standard for the trade across Canada, stewarded by the Canadian Council of Directors of Apprenticeship. A Red Seal endorsement on an Ontario Certificate of Qualification means the qualification is recognized in other provinces and territories without re examination, which matters for workers moving between provinces and for employers hiring from outside Ontario.
The Red Seal exam for this trade, written under the national title Lather (Interior Systems Mechanic), has 125 multiple-choice questions, each with four possible answers and exactly one correct answer.
Already experienced? The Trade Equivalency Assessment
Workers with experience from outside Ontario's apprenticeship system, or from another country, can apply for a Trade Equivalency Assessment instead of starting an apprenticeship. Approval requires verifiable evidence of competency in the trade's Training Standard and experience at least equal to the trade's total training time; if approved, you challenge the certifying exam directly. The assessment costs $235 plus HST, and a reassessment with new evidence costs $100 plus HST, per Skilled Trades Ontario's Trade Equivalency Assessment page.
Certification is not the only paperwork
A Certificate of Qualification covers the person. Running a business in the trade carries its own obligations: many Ontario municipalities require a contractor licence on top of personal certification, and construction employers must complete WSIB registration before work begins. Both are indexed on our sister site: municipal contractor licensing requirements by city and WSIB Form 1000, registration of constructors and employers, on Ontario Trade Registry.
What does a drywall, acoustic and lathing applicator earn in Ontario?
| Median wage | $35.48 per hour |
|---|---|
| Low | $24.00 |
| High | $48.73 |
| Occupation measured | Plasterers, drywall installers and finishers and lathers (NOC 73102) |
| Reference period | 2023-2024 |
Published by Employment and Social Development Canada through Job Bank, for Ontario as a whole. Read it as the pay range for the occupational group this trade belongs to, not a guaranteed rate: one NOC code can cover more than one trade, and wages vary by region, employer and experience.
Is the 451A recognised outside Ontario?
This trade has been part of the Interprovincial Red Seal Program since 1991. 11 of Canada's 13 provinces and territories designate it Red Seal: AB, BC, MB, NB, NL, NS, ON, PE, QC, SK, YT, Ontario among them. Its National Occupational Classification code is 73102, which is how federal labour market data refers to this occupation.
Where can you train as a drywall, acoustic and lathing applicator in Ontario?
| Private training providers | 4 |
|---|---|
| Approved sponsors | 37 employers registered to train apprentices |
| Apprentices in training | 1,169 |
Counts are from Ontario's published apprenticeships dataset. A sponsor is the employer or union that registers and trains the apprentice; you need one before an apprenticeship can start.
How dangerous is construction work in Ontario?
Ontario does not publish injury figures per trade, only by sector. In 2024 the Ministry of Labour recorded 18 worker fatalities and 442 critical injuries under the construction health and safety program. See the ten-year counts and what they leave out.
Related Ontario trades
Other construction sector trades with certification records on this registry:
Official verification sources
- RegulationO. Reg. 876/21, Prescribed Trades and Related Matters (e-Laws)
- Certifying bodySkilled Trades Ontario: Drywall, Acoustic and Lathing Applicator
- ActBuilding Opportunities in the Skilled Trades Act, 2021 (e-Laws)
- WagesJob Bank wage data, Employment and Social Development Canada
- Red Seal profilered-seal.ca: Drywall, Acoustic and Lathing Applicator trade profile
- Participation dataOntario open data: Apprenticeships dataset
Classification, exam requirement and ratio status on this page are read directly from O. Reg. 876/21 as consolidated on e-Laws, not from secondary summaries. Facts not yet verified against a primary source are marked as not published rather than estimated.