A spark arrester also known as a cap will keep out rain. Additionally it will also keep out birds, squirrels, other critters, as well as debris.
of blockage in the flue can choke a fire, causing smoke and
dangerous carbon monoxide fumes to spill back into the room.
Here are some links to more important information:
Serving Clark County since 1982
Washington State Contractor # matchcs895mq
P.O. Box 87023
Vancouver, WA 98687