WETT Notes for inspectors

SUPER CHIMNEY:

  • 2/3/10 rule.
  • Must be braced to roof if taller than 5′, lags must be in rafters.
  • Vertically supported every 6′ with stand offs.
  • Look for pitting, rusting, loose or damaged.
  • Must have chimney cap.
  • Look for Tee with clean out.
  • Super chimneys should be enclosed when passing through living space.
  • Insulation needs to be kept away 2″ when in attic.  Either with radiation shield or boxed in
  • A dropped ceiling still needs combustible clearance.  A cathedral ceiling support can be used.
  • Basements should NOT have a super chimney for 2 reasons:
    • In winter, basements are usually de-pressurized.
    • It’s nearly impossible to clean out because Tee is at ground level.
  • Ice deflector is recommended when super chimney is near eaves.

 

MASONRY CHIMNEY:

  • 2/3/10 rule.
  • Over 30″ wide requires cricket or saddle.
  • Check masonry and chimney cap.
  • Make sure flue tile is not cracked.
  • Ember arrestor rain cap required.
  • Needs lateral support every 12′.
  • Masonry chimney MUST rest on foundation that is deeper than the frost line.
  • If clay liner is severely damaged, recommend pulling new stainess steel liner.
  • Flue must not be inclined more than 45 degrees.
  • There should be a sealed bond-break between masonry cap and flue.
  • Masonry chimneys must have a clean-out at base of chimney.
  • Roof framing must be kept away 1/2″ for exterior chimneys and 2″ for interior chimneys.
  • Joists can be fastened to masonry chimneys provided that masonry is minimum 11.5″ thick.

 

FLUE PIPE:

  • Can’t exceed 10′ in length.
  • 18″ clearance unless double-walled.  Shield either on wall or on pipe (28 gauge minimum), 7/8″ away for 66% reduction.
  • Offsets not to exceed 180 degrees.
  • No galvanized steel allowed.
  • Horizontal slope minimum 1/4″ per foot.
  • Expansion joint/slip joint required for fully vertical installations.
  • Minimum 3 screws per joint.
  • Crimped/male end down unless double-walled pipe.
  • Must NOT EVER pass through combustible framing without an insulated thimble.
  • NOTE:  Ceiling pass-through may provide less than 18″ clearance for flue pipe below, however this is acceptable.

 

STAINLESS STEEL LINER:

  • Approved connectors are available if liner is not long enough.
  • Insulation surrounding a liner in a masonry chimney MAY or MAY NOT be allowed, depending on mfg. recommendations.
  • Liners surrounded by insulation develop draft faster, are more stable and don’t develop creosote build-up as fast.
  • For hearth-mounted stoves, the opening (abandoned firebox) must be sealed to prevent drawing room air into chimney cavity.

 

WOOD STOVE:

  • Certified vs. Un-certified.
  • Un-certified clearances:  4′ on all sides(w/o shielding), 3′ if shielded, & 60″ to ceiling.
  • See list for un-certified leg heights.
  • Certified:  follow certification data plate.  Ceiling height: (82″) – (stove height) = Ceiling clearance.
  • Check stove for damage, cracks, etc.
  • Required:  4′ space at feeding door (front or side, depending on stove).
  • 18″ front floor protection, 8″ sides and rear.
  • Floor protection must be non-combustible, continuous material.
  • Check firebrick inside.

 

WOOD STOVE INSERT:

  • Continuous stainless steel liner.
  • Try to check liner connection.
  • Check box condition.
  • Check firebrick inside.

 

FACTORY-BUILT FIREPLACE:

  • Mandatory make-up combustion air vents required in Ontario.

 

MASONRY FIREPLACE:

  • If fireplace floor is LESS than 6 sq. ft, 16″ hearth at front and 8″ at sides.
  • If fireplace floor is MORE than 6 sq. ft, 20″ hearth at front and 12″ at sides.
  • Additional 1″ extension needed for every 2″ in height over 6″.
  • Must be on 4″ concrete slab, ensuring that wood form is removed from below.
  • Must have flue damper.

 

MANTLE:

  • If mantle is combustible and projects LESS than 1.5″, then 6″ clearance between top of firebox opening and mantle is required.
  • If mantle is combustible and projects MORE than 1.5″, then 12″ clearance between top of firebox opening and mantle is required.
  • If heat circulation vents are present HIGHER than top of firebox opening, mantle clearances will be measured from top of vents.

 

GENERAL NOTES:

  • Wood stoves installed in modular homes must be certified for this particular use (combustible walls and floors).
  • Appliances located in rooms with fuel vapours present (eg: garage) must be located 18″ above floor on non-combustible pad.
  • Carbon monoxide detector is MANDATORY in rooms with wood burning appliances.
  • Oil and wood burning appliances can share a flue, provided that:
    • Oil appliance is approved for such use.
    • Appliances are both on same floor.
    • Oil appliance connects ABOVE wood appliance to flue.
  • Metal shields must always be 28 gauge minimum material thickness.
  • Flue pipe may be reduced, provided sufficient draft is still provided.