A roof for the flue, and the gap that has to stay open

Rain caps, compared on clearance as much as on cover

A rain cap keeps water out of the flue, and the whole of its design is a compromise between covering the opening and leaving it open. The internal diameter or the stack dimensions decide fit. The overhang — how far the cover extends past the opening — decides how much driven rain it actually stops. And the opening height, the gap between the top of the flue and the underside of the cover, decides whether the flue still breathes: too low and the cap throttles the draught, which shows up as a stove that lights badly on still days. Makers publish the first two and rarely the third, which is why the pages here print it whenever it appears. The material is stainless, copper or galvanised steel, and on a rain cap the choice is visible for twenty years — galvanised streaks, copper weathers, stainless does neither. The fixing is the practical question: an internal clamp needs a round flue in good condition, a strap or a plate suits a masonry stack, and a cap that relies on its own weight is a cap that will be recovered from a gutter. We compare material thickness, material, hood diameter, pipe diameter, dimensions, fixing, claimed effect and origin.

These parts, set out figure by figure

1. 

   QWORK Stainless 304 Rain Cap, 110 mm

   A small 304 stainless cap with a stainless screen and curled edges — the smallest and cheapest fit on this shelf.

   Material thickness

   Not published

   Material

   Stainless steel 304, stated rustproof, corrosion-resistant and not easily deformed · A stainless barrier grid, stated to keep dirt out · Curled, stated so they do not easily cut hands

   Hood diameter

   The maker does not state it.

   Pipe diameter

   110 mm — the smallest in this family

   Dimensions

   The maker does not state it.

   Fixing

   Not published

   Claimed effect

   Stated suitable for any climate and resistant to cold and high temperatures · Roof ventilation outlets as well as chimney caps

   Origin

   The maker does not state it.

   Amazon reference

   B0CPXW4JLK (one reference across 6 Amazon marketplaces)

   EAN

   0795973636584

   • Curled edges rather than raw cut sheet, which is the detail that matters when fitting at roof height
   • A stainless screen included, so it is a debris barrier as well as a rain hood
   • No material thickness published, where three listings in this family give theirs

   Best for: A 110 mm vent or flue outlet, where a small stainless cap with a screen is all that is wanted

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2. 

   KOTARBAU Galvanised Rain Cap, Ø 130 mm

   The 130 mm version of a fully dimensioned galvanised hood — seven published measurements, and a draught claim contradicted elsewhere on this shelf.

   Material thickness

   Approximately 0.1 cm

   Material

   Galvanised steel · 0.53 kg

   Hood diameter

   23 cm

   Pipe diameter

   13 cm

   Dimensions

   19.5 cm · 31 cm

   Fixing

   The maker does not state it.

   Claimed effect

   Stated to improve the air supply and so the efficiency of the stove

   Origin

   The maker does not state it.

   Amazon reference

   B0CTMCR6DL (one reference across 5 Amazon marketplaces)

   EAN

   5904994074274

   • Seven published measurements, which only one other listing in this family approaches
   • The pipe length is published, so how far it engages the flue is known before ordering
   • The draught claim is contradicted by another listing on this shelf, which states the draught is slightly impaired

   Best for: A 130 mm flue pipe where a fully dimensioned cap matters more than the grade of steel

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3. 

   H&M Germany Push-In Rain Hood, 150 mm

   Acid-resistant V4A stainless on spring clips, with both insertion diameters published — and the only honest account of draught on this shelf.

   Material thickness

   The maker does not state it.

   Material

   V4A 1.4404 acid-resistant stainless, 0.6 mm thick, throughout

   Hood diameter

   Approximately 148 mm at the top, approximately 145 mm at the bottom including the spring clips · Not published

   Pipe diameter

   All chimney types with a round inner pipe — refurbishment liners, clay or fireclay pipe, twin-wall stainless chimneys, garden fireplaces

   Dimensions

   The maker does not state it.

   Fixing

   Spring clips — no screwing and no gluing, stated · Measure the internal diameter of your chimney mouth BEFORE buying, stated in capitals

   Claimed effect

   Stated that the large distance from hood to mouth impairs the draught only minimally, and clearly improves it where downdraughts strike the mouth · Downdraughts and spark throw

   Origin

   The maker does not state it.

   Amazon reference

   B00ZIM10PY (one reference across 1 Amazon marketplace)

   EAN

   4250112305463

   • The only acid-resistant grade on this shelf, which is what flue condensate actually attacks
   • Publishes both insertion diameters and tells the buyer which measurement to take
   • Point six millimetres is the thinnest material published in this family

   Best for: A round flue liner or clay pipe where the cap has to grip without fixings, on a chimney that suffers downdraught

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4. 

   VEVOR Stainless 304 Chimney Cap, 416 × 416 mm

   A meshed square cap in 304 stainless, 416 mm across, with two mounting methods, pre-drilled holes and all the screws in the box.

   Material thickness

   The maker does not state it.

   Material

   Stainless steel 304, stated more rust-resistant than galvanised steel or 430 stainless · Stainless mesh

   Hood diameter

   The maker does not state it.

   Pipe diameter

   Masonry chimneys, metal chimneys and outdoor stove chimneys

   Dimensions

   416 × 416 × 250 mm

   Fixing

   Two methods — side mounting or mounting from underneath, with pre-drilled holes and a four-step procedure · Expansion screws, stated to prevent tipping in the worst weather · Sufficient screws and nuts plus assembly instructions

   Claimed effect

   Birds, rodents, other animals, leaves, rain, snow and sparks

   Origin

   The maker does not state it.

   Amazon reference

   B0CD7FN1V3 (one reference across 6 Amazon marketplaces)

   EAN

   0840349948812

   • Two mounting methods, which is what a stack of unknown construction needs
   • Pre-drilled holes and all the fixings supplied, so nothing is improvised on a roof
   • Mesh collects soot and needs an annual look, which the listing does not raise

   Best for: A masonry or metal stack around 400 mm square where animals, not just rain, are the problem

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5. 

   FIREND Stainless Chimney Cover, 600 × 600 mm

   The thickest material on this shelf, with the bracket count published — and the size above which a third bracket is fitted.

   Material thickness

   The maker does not state it.

   Material

   Stainless steel, 1.0 mm — the thickest in this family · Not published

   Hood diameter

   The maker does not state it.

   Pipe diameter

   600 × 600 mm

   Dimensions

   Not published

   Fixing

   2 stainless brackets; 3 brackets from a size of 860 × 1,000 mm upwards, stated · Stated robust and stable · Not described

   Claimed effect

   Four, all about the material and the supports

   Origin

   The maker does not state it.

   Amazon reference

   B08Q7MX15V (one reference across 2 Amazon marketplaces)

   EAN

   5902539901023

   • One millimetre of stainless, the heaviest gauge published on this shelf
   • Publishes how many brackets it has and at what size a third is added
   • No grade, no height, no fixing method and no weight

   Best for: A 600 mm stack where the gauge of the metal matters more than the description

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6. 

   SAREI Haus- und Dachtechnik Stainless and Copper Chimney Hood, 700 × 700 mm

   Stainless and copper at 0.8 mm in the largest size on this shelf, 700 × 700 mm — with a fitting video the maker made for it.

   Material thickness

   0.8 mm, described as professional gauge

   Material

   Stainless steel and copper

   Hood diameter

   The maker does not state it.

   Pipe diameter

   The maker does not state it.

   Dimensions

   700 × 700 × 200 mm — the largest in this family

   Fixing

   Extra robust screw points on the bracket, stated · A purpose-made video from the maker, stated

   Claimed effect

   Optimal extraction of flue gases, stated optimised by less wind ingress · Excessive wet in the chimney pipe and strong wind ingress

   Origin

   German manufacture, stated

   Amazon reference

   B00MEL5YAO (one reference across 6 Amazon marketplaces)

   EAN

   4260036892093

   • The only listing on this shelf to publish a height as well as a footprint — 200 mm of clearance
   • Copper as well as stainless, which weathers to a finish rather than staying bright
   • The stainless grade is not published, and neither is the copper’s role in the construction

   Best for: A large stack on a visible roof, where the hood is part of the elevation and not just a lid

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7. 

   KÖNIGSPROD Napoleon Stainless Chimney Cover, 600 × 600 mm

   A stainless cover on profile supports at 600 × 600 mm, offered in every size — described in five lines that carry no other figure.

   Material thickness

   Not published

   Material

   Stainless steel, grade not published · Stated to improve the look of the chimney

   Hood diameter

   The maker does not state it.

   Pipe diameter

   600 × 600 mm, with the title stating all sizes are available

   Dimensions

   Not published

   Fixing

   Profile supports, stated to give a very stable construction · Stated maintenance-free and corrosion-resistant

   Claimed effect

   Optimal extraction of flue gases

   Origin

   The maker does not state it.

   Amazon reference

   B0DLPBNHX3 (one reference across 5 Amazon marketplaces)

   EAN

   4251428113704

   • Offered in all sizes, which a masonry stack needs since no two are alike
   • Profile supports rather than flat straps, which resist bending under wind uplift
   • Five published features and not a single figure among them

   Best for: A stack of an unusual size, where the range matters more than the specification

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