Harvia WHM22 Rubber Rain Collar for Tilted Roofs (Rain Flange, Black)

The Harvia WHM22 rubber rain collar (Harvia part SPWHM22, “rain flange, tilted, black”) is the replacement weather seal for Harvia WHP steel chimneys installed through tilted / pitched roofs. The flexible black rubber boot clamps around the 220 mm insulated chimney casing and conforms to the roof slope, keeping rain and meltwater out of the lead-through. If the tilted rain flange on your chimney kit has aged, cracked, or was damaged during installation, this is the correct replacement.

Features

• Genuine Harvia replacement rain collar (SPWHM22) for WHP steel chimneys
• Tilted profile — conforms to pitched roof slopes
• Flexible black rubber seals around the insulated chimney casing
• Restores the weather-tightness of the roof lead-through
• Limited 2-year warranty (consumer use); limited 1-year warranty (commercial use)

What’s Included

• Rubber rain collar, tilted

Specifications

Compatibility

Replacement for the tilted rain flange used in the Harvia WHP1500 / WHP1500M chimney kits and the WHP-AS tilted roof accessory kit. For flat roofs and barrel saunas, use the WHM24 symmetric rain collar instead.

Note: as a manufacturer replacement part, this item is not returnable — to preserve the originality, operation, and safety of replacement parts.

Good to Know

WHM22 or WHM24 — which collar do I need?

WHM22 is the tilted rain flange for pitched roofs; WHM24 is the symmetric flange for flat roofs and barrel saunas. Match it to how your chimney exits the roof.

When should the rain collar be replaced?

Inspect it whenever you sweep the chimney. UV exposure and heat cycling eventually stiffen and crack the rubber; replace it at the first sign of cracking or if water stains appear around the ceiling lead-through.

How is it installed?

Harvia specifies silicone sealant beneath the flange, roof screws spaced no more than 35 mm apart, and a fully tightened clamp with no gaps in the seal. Where sliding snow can hit the flashing, fit a snow barrier above the chimney.

Designing a Harvia Chimney System

Every part on this page belongs to Harvia’s modular WHP steel chimney system: a 115 mm (4.5″) smoke path inside a 220 mm (8.6″) insulated casing, assembled with slot-and-lock joints. Here is how a complete system comes together:

1. Start with the chimney. For pitched roofs, the WHP1500 kit (1500 mm chimney plus rain cap, tilted rain flange, smoke pipe, and ceiling lead-through set) is the core of the system. For flat roofs and barrel saunas, the WHP1000500 package bundles the chimney with the symmetric roof kit.
2. Connect the stove. Bridge the stove collar to the insulated chimney with 115 mm WZ smoke pipes (20 cm, 50 cm, or 1 m). Add the WZ115030SP damper plate at the stove to control draft while firing, a WZ115120 reducer where pipe sections step down, or the WZ115155 adapter if you are transitioning to 6″ US Class A pipe.
3. Reach your height. Add WHP500 (500 mm) or WHP1000 (1000 mm) extensions. Stay within Harvia’s limits: 5.0 m (16.4 ft) total chimney height, no more than 2.0 m (6.5 ft) above the last support, lateral supports every 3.0 m (9.8 ft).
4. Go through the roof. Choose the roof kit that matches your roofline — WHP-AS for tilted/pitched roofs, WHP-ASSYM for flat roofs and barrels. Replacement rain collars: WHM22 (tilted) and WHM24 (symmetric). Add a snow barrier above the chimney where sliding snow can load the flashing.
5. Seal and control. The WHM25 vapor barrier restores the vapor-tight layer where the chimney passes the sauna ceiling; the WHP270 insulated damper closes the flue after the fire is fully out so the sauna holds its heat.
6. Finish the stove side. Stone-filled covers — WL300 for Legend stoves, WL300PC for Cilindro — absorb radiant heat from the smoke pipe and significantly reduce its required safety distances.

Key clearances and rules: vertical installation only; 100 mm (4″) from the insulated casing to combustibles; 500 mm (stainless) or 375 mm (black) from non-insulated smoke pipe unless shielded; designed for wood-burning stoves in standalone outdoor sauna buildings. Confirm your plan with your local building authority — and if you would like help speccing the system, talk to us; we design these daily.

Shop the Complete Harvia Chimney System

1. Start with the chimney

• WHP1500 Chimney Kit, 1500mm (stainless or black) — the system core
• WHP1000500 Complete Chimney Package for flat roofs & barrel saunas

2. Connect the stove

• WZ Smoke Pipes, 115mm (20 cm / 50 cm / 1 m, stainless or black)
• WZ115030SP Stove-Side Damper Plate (draft control while firing)
• WZ115120 Reducing Pipe (joins mismatched pipe sections)
• WZ115155 Adapter, 4.5″ Euro to 6″ USA (hybrid Class A transitions)

3. Reach your height

• WHP500 Chimney Extension, 500mm
• WHP1000 Chimney Extension, 1000mm

4. Go through the roof

• WHP-AS Roof Accessory Kit for tilted / pitched roofs
• WHP-ASSYM Roof Accessory Kit for flat roofs & barrel saunas
• WHM22 Replacement Rain Collar, tilted roofs (this page)
• WHM24 Replacement Rain Collar, flat roofs & barrels

5. Seal and control

• WHM25 Chimney Vapor Barrier (seals the ceiling penetration)
• WHP270 Insulated Smoke Damper (retains heat after firing)

6. Finish the stove side

• WL300 Smoke Pipe Cover for Legend stoves (cuts clearances)
• WL300PC Chimney Cover for Cilindro stoves (cuts clearances)