Vapor Barrier: Do I really have to install plastic?
HTML-код
- Опубликовано: 11 сен 2024
- Many people have seen plastic (poly) installed on the inside of walls or a faced paper insulation batt to meet vapor barrier requirements. Plastic installation is pretty straight forward in that it's installed on the inside of an exterior wall and should be free from holes or cuts.
As an inspector, I run into issues when a homeowner uses faced batts for their vapor barrier but leave gaps, holes and missing vapor protection. Faced batt insulation can become more work than you might expect trying to get a nice clean vapor barrier. In these situations, I will typically suggest a plastic or a PVA. Check to see if your local building department will accept a PVA (Primer Vapor Application) in lieu of a plastic or faced batt. For those of you who would prefer that your wall breathe, it may be the way to go.
Subscribe to this channel and check out other videos made especially for homeowners, like you, to help you get through home projects confidently, while also saving time and money on expensive re-dos. Visit www.buildingcodetips.com for blogs and guides on building code, construction processes, tips, tricks and more - all for the DIYer.
Disclaimer: Videos produced by Building Code Tips are for informational purposes only. Viewers must be aware that any projects performed utilizing the guidance and/or suggestions given by Building Code Tips and its representatives is at the viewers sole risk and Building Code Tips cannot be held liable if any damage is caused to their homes, surrounding structures, persons, etc. With different codes around the world and constantly changing standards, regulations and rules, it is the sole responsibility of the viewer to educate themselves on their local requirements before undertaking any sort of project and Building Code Tips cannot be held liable for information inaccuracy.
This was incredibly helpful. Thank you!
I am glad it was helpful!!
I live in zone 5 and I really enjoyed tearing out ALL the panels and sheet rock and repairing the sills on the first floor of my house due to plastic vapor barrier. Hot humid air from outside condensed on the back side of the plastic in the summer. The water collected and ruined my sills not to mention the mold. Everything got repaired at a huge cost and then I sold the house in good conscience. Now the house I bought, is beginning to have the same problem. Some of my sheet rock is water stained in several places. So, I'm rethinking this plastic vapor barrier deal. Might be perfect for some, but I am not seeing it.
Sorry to hear about your issues. I am definitely not a fan of the plastic vapor barrier. Many contractors in my area shy away from it when possible.
I couldn't watch this put your camera or phone on a tripod.
Thanks for the suggestions!
We never put poly over faced insulation . I've remodeled homes that had poly over faced with black mold growing in between poly and facing . The building has to breath ... jmo
Thanks for the comment! Totally agree about houses needing to breath, in our area many houses are built without a plastic or paper vapor barrier in favor a PVA.
I had this discussion the city. I told them that without vapor barrier, I can get rid of moisture with my dehuimidifier. If I install plastic I'm just going to trap that moisture. His response was to just redo the basement in 4-5 years.
@@dhh488 Interesting, you must live in an area where vapor barrier is required no matter what.
@@buildingcodetips You're right.Not very smart in my opinion.
I live in NE Kansas unit 4. I have mixed feelings. It’s humid is July and -13 in January, but outside of 3 months a year theirs no humidity, not super cold, pretty mild. My wife and I are building a house. Idk if I should do a vapor barrier with plastic or not. I Have unfaced insulation, old guys say yes, guys my age say no.
Thats a hard one! I like my walls to breathe but I also don’t live in a humid area. Our summers are dry heat. What are the local builders doing for new builds, in new neighborhoods? The track home builders
In what climate? I live in the mid-west where the hot side is inside in January and outside in July.
Climate zones 4,5,6,7 and 8 allow for the PVA, type 3, vapor retarder if proper conditions are met. I live in climate zone 5 which has all 4 seasons with hot on the inside in January and on the outside in July.
Here is a link to the climate zone map:
drive.google.com/file/d/1RqTQdD2pCVbNM-aZGLxatYBVQ-kmj08S/view?usp=sharing
Here is a link to the type 3 vapor retarder code reference for minimum conditions: drive.google.com/file/d/1f_3GYYqAjXCsajBKQQOm1y4umG6bBd4q/view?usp=sharing
Hope that helps!
What mil thickness plastic is the best for exterior garage walls and ceiling?
Hey Oxford, 6 mil is the most commonly used plastic vapor barrier. Though, at least in my area, if the garage is un heated you dont need a vapor barrier. Unless of course you want it anyways.
@@buildingcodetips Thank you!
@@buildingcodetips I have one more question. I am planning to insulate my attached one car garage. It will not be heated. It has 2x6 walls. Would there be a significant difference if I used insulation for 2x4 walls as opposed to insulation for 2x6 walls? I am looking at the cost difference between the two.
@@oxfordmontello3281 Hey Oxford, If you aren't heating it per say but just looking to cut the edge than the cheaper R-13/R-15 for 2x4 walls should work. If you think you may heat it down the road I would fill the full stud bay with a R-19/R-21. Are you insulating the ceiling? That might be the most important area if the goal is to trap in any residual heat/cooling. Hope that helps a little!
@@buildingcodetips Thank you! This helps immensely! I will be insulating the ceiling. What should i go with in the ceiling if I never plan to heat the garage? I am doing all the work myself to save on cost.