Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

The home I purchased has a crawlspace below an addition that was put on to the original structure. The HVAC contractor that did the work ran 2 long runs of flex-duct to the 2 registers in the room of the the crawl space.

Is this acceptable? Do I need to be concerned about the elements or possibly animals getting into the crawl space and chewing holes in the flex duct?

share|improve this question

Flex duct is commonly used in crawl spaces. That said it is vulnerable to punctures, animals and other hazards. Animals have no particular reason the chew the ducts, but sometimes they will anyway. Flex duct is cheaper to install than hard duct, and (at least initially) it is easier to make it not leak.

Put in some rat traps and be happy I'd say.

share|improve this answer

I would not use flexible duct in a crawl space. It is like a 4 lane freeway for animals and bugs. Rigid duct is very easy to piece together. Even long runs might take you an extra few minutes.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.