why don't fireplaces get filled with water when it rains?

Question

some chimneys have tiny lttle roofs, but what about the ones that don't?

Answer 1

Most chimneys, if they are built properly, have a positive updraft all of the time. Air flows UP the chimney from the house, preventing the water droplets from entering the chimney and 'filling the fireplace with water'.

The little 'roofs' as you called them, actually prevent any downdraft and help create a cross-draft for the smoke if there is any wind blowing while a fire is burning.

Answer 2

Large chimneys usually have small roofs to cover the opening. All chimneys have a flue (an adjustable metal plate inside the top of the fireplace where it goes into the chimney. It is used to regulate the draft {airflow} in the chimney) to prevent water from dousing the fire. Also, if the fire is going, the heat would evaporate the rainwater before it got far down the chimney. Additionally, soot in the chimney acts as a sponge, of sorts, to absorb the moisture. When the humidity returns to normal the soot will dry out. The bad part of this is that this is what causes buildup of soot in the chimney so, to stay safe (prevent chimney fires), you should have the chimney swept at regular intervals.

Answer 3

All chimneys are constructed with various items that prevent sparks going to your roof as well as items of some kind to prevent rain entering. Some of the latter even have a channel that diverts to water to another place.

Answer 4

It's not a box. If the water came in, it would run through the chimney, through the fireplace and onto the floor!

Answer 5

Depends on how much rain, in a really hard downpour I do get a little down by the hearth. I have put a cap on it now to help stop it and it has worked so far. good luck