Should I vent my attic when adding open cell spray foam insulation to the walls and rafters, given the conflicting information and existing air handler in the unconditioned space?
Asked by Pat Young 
7 months ago
Last Updated: May 22, 2024
Right now, I have blown in cellulose insulation on my attic floor, and I’m planning to add open cell spray foam insulation on the walls and rafters. I’m a bit confused about whether my attic should be vented or non-vented. I have an air handler up there, but the space isn’t conditioned. Also, my attic currently has a ridge vent and baffles for ventilation.
You’re all set
So, thinks the attic should not be vented?
I personally don’t believe it makes a big difference. The insulation seems fine. I would proceed with it if it was my own house. Have you consulted with the insulation company?
I’ve never come across anything like that before, but I have constructed many homes
It’s important to have proper ventilation in your attic
From the insulation company mentioned that open cell spray insulation doesn’t require ventilation
Anonymous contributor I’ve been reading up on this article online but I’m still not sure about vented and unvented. I saw online that unvented seals everything off and stops moisture
I came across this article online but I’m still uncertain about vented and unvented. From what I’ve read, unvented completely seals everything off and prevents moisture.
https://www.retrofoamofmichigan.com/blog/does-my-roof-need-to-breathe?hs_amp=true
It’s sort of similar to trying to self-diagnose your illness using Google… it’s best to consult a professional haha
You might be able to skip the baffles and seal it up, but I would recommend having a ridge vent installed on my home
Thanks for the info, . I’ll stick with the ridge vent but I’m considering a non-vented attic based on the recommendation from the insulation company.
For your ventilation system, consider using the ridge vent and air handler. Just make sure not to block them when spraying insulation. It’s important to allow airflow so heat can escape in the summer and moisture can escape in the winter. That’s my advice, but I’m not an expert.
Make sure the air handler has both an intake and an exhaust on that floor.