Why Use a Stainless Steel Rain Cover for Your Chimney? There is a Very Good Reason…
I have been installing stainless steel rain covers since the beginning of my career (1991). This has been the standard because we did not want to sell a cover that would rust out after 5 or 10 years.
Having said that, there are rain covers made of galvanized steel that are well designed, well constructed and of high quality. There are also galvanized covers that are junk.
The cost difference between a high-quality stainless steel cover and a high-quality galvanized cover is about $30.00 to $40.00 – you will potentially save a lot more than that in the long run (not to mention the hassle) if you just buy a really good quality cover (stainless steel).
Galvanized steel rain caps can fail over time, especially when installed over an oil-fuel furnace flue. Oil furnace exhaust just tears up these types of caps after a few years.
Stainless steel rain covers are best over oil furnace chimney flues.
Exception: Do not put a stainless steel cover over a chimney flue that exhausting a natural gas-fueled appliance.
It has been my experience that the natural gas exhaust will actually cause the stainless steel to rust. Use a galvanized steel cap or an aluminum cap over a chimney flue that is exhausting a natural gas furnace or hot water heater.
Above: Stainless steel cap with a large top to deflect rain. Good, sturdy material and construction.
Above: Galvanized steel cap beginning to rust.