Discussion Forum

Discussion Forum

Sealing Air Ducts with mastic

Zach | Posted in Energy, Heating & Insulation on

I want to seal the metal air ducts in my crawl space with mastic. Can I run my A/C right after I’ve applied the mastic?  It’s summer in North Carolina and I’m not sure how long I can go without running the A/C.

Replies

  1. florida | | #1

    I'd let it dry for at least 4 hours before running the AC.

Log in or create an account to post a comment.

Become a member and get full access to FineHomebuilding.com

Video Shorts

Categories

Discussion Forum

Recent Posts and Replies

  • |
  • |
  • |
  • |
  • |
  • |
View More Create Post

Up Next

Video Shorts

Featured Story

Big Doors Have Big Challenges

Engineered materials and vacuum-press laminations prevent warping and keep a tall, flush-panel door from being excessively heavy.

Featured Video

How to Install Exterior Window Trim

Learn how to measure, cut, and build window casing made of cellular PVC, solid wood, poly-ash boards, or any common molding material. Plus, get tips for a clean and solid installation.

Related Stories

Highlights

Fine Homebuilding All Access
Fine Homebuilding Podcast
Tool Tech
Plus, get an extra 20% off with code GIFT20

"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.

Fine Homebuilding Magazine

Fine Home Building

Membership & Magazine

© 2025 Active Interest Media. All rights reserved.

Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.