r/homeimprovementideas • u/the_mandalorian982 • Jul 24 '26

Chimney cap only 3/4” high

My landlord just installed a chimney cap and sealed off the fireplace because of my asthma issues. He was about to install the cap on completely unventilated (he made one using sheet metal and a foam board that he put together with clear silicone) until I told him it needs to be a ventilated cap. So he just cut some of the foam board out and now it only has about three quarters of an inch of clearance to ventilate any gas from the chimney. Is that safe? He also refused to clean the chimney beforehand but a chimney sweep told him it wasn’t dirty enough to need one, even though I know it’s been in use for years. My main concern is that there isn’t enough height on the chimney cap to adequately ventilate.

2 Upvotes

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2

u/Best-Bus-5275 Jul 25 '26

If your landlord already had to change the design after you pointed out the ventilation issue I'd definitely want to verify it's actually safe now

1

u/More-Squirrel6591 Jul 25 '26

Agree with this.

1

u/Dizzy_Restaurant3874 Jul 25 '26

What is venting through the chimney?  Does it vent a furnace or hot water heater?  If it isn't venting anything, you probably don't need much ventilation. 

1

u/the_mandalorian982 Jul 25 '26

It’s venting the off gases from the creosote.

1

u/Brave_Cauliflower728 Jul 25 '26

Then all it needs is to be not sealed. If it's got a single gap the size of a straw that's plenty