FHB Logo Facebook LinkedIn Email Pinterest Twitter X Instagram Tiktok YouTube Plus Icon Close Icon Navigation Search Icon Navigation Search Icon Arrow Down Icon Video Guide Icon Article Guide Icon Modal Close Icon Guide Search Icon Skip to content
Subscribe
Log In
  • How-To
  • Design
  • Tools & Materials
  • Restoration
  • Videos
  • Blogs
  • Forum
  • Magazine
  • Members
  • FHB House
  • Podcast
Log In

Discussion Forum

Discussion Forum

low-budget air-seal testing

| Posted in General Discussion on January 2, 1999 01:11am

*
Steve

Bump?

With tongue firmly planted in cheek I offer the following: maybe there are just so many places for your incense smoke to exit that it’s taking the path of least resistance and just sort of swirling around looking for enlightenment, or maybe exlightenment. I suggest you sit in a corner and repeat the OM(G)chant where OM stands for Oh My. . . God how did I let myself get caught like this!!

And my wife thinks that I’m the bull goose procrastinator

Spring will come. . . eventually

Zenishly

Patrick

Reply
  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles

Replies

  1. Patrick_M. | Jan 02, 1999 01:11am | #2

    *
    Steve

    Bump?

    With tongue firmly planted in cheek I offer the following: maybe there are just so many places for your incense smoke to exit that it's taking the path of least resistance and just sort of swirling around looking for enlightenment, or maybe exlightenment. I suggest you sit in a corner and repeat the OM(G)chant where OM stands for Oh My. . . God how did I let myself get caught like this!!

    And my wife thinks that I'm the bull goose procrastinator

    Spring will come. . . eventually

    Zenishly

    Patrick

  2. Guest_ | Jan 02, 1999 02:22am | #3

    *
    Hi Patrick,

    Bump is what you do when you see your post going unanswered and sinking fast down the list. It raises it to the top in hopes of people seeing it with fresh eyes ;)

    Steve

  3. Patrick_M. | Jan 02, 1999 03:19am | #4

    *
    Hi Steve

    Let's bump it again. With my tongue back in it's somewhat normal spot I offer the observation that perhaps with so many huge holes in your building envelope you can't hope to do any kind of test (cheap or otherwise) that would be of any use. Fred's weatherization site continues to be only partially complete so I fail to see how anybody can get a handle on what he is promoting, hence your possible misunderstanding of the "neutral pressure plane". I doubt that any of his science would work on a place like you described.

    I guess you're really wondering where to start. . . why at the beginning of course. . . or as current wisdom would have it, at the top.

    The stovepipe thimble is meant to provide an air space for fire safety
    you should not block it up, replace the existing detail with a piece of insulated pipe and run that through the wall, it still requires 2" air space but with metal firestop designed for this purpose you can cut the draft down considerably, alternatively re-route the stove pipe up through the building, using insulated pipe from the first floor ceiling upwards and out the roof, where you can get a somewhat better sealing arrangement, although never air tight.

    Happy New Year,eh?

    Patrick

  4. Guest_ | Jan 02, 1999 05:38am | #5

    *
    Hi Patrick,

    I appreciate your talking about this with me. It's going to be 20 below here tonight.

    I was blowing expanding foam into the cracks between my timberframe sill and stone foundation in the vacinity of my copper pipes today. That foam just doesn't like to expand or cure at 0 degrees. I wonder why? I've only known about the need to to do this since the little freezing incident last winter, so you would have thought I would have got around to it a little sooner than today, Eh? I win the procrastination prize!

    I've hashed out Fred's thoughts in general here and in other forums elswhere, and feel I have a pretty good handle on his theories. It is annoying that he doesn't fill out his web site a little more, but what can you expect for free. He's a pretty busy guy. Without too persistent bugging you can usually get him to explain stuff here.

    His description of the neutral pressure plane is the level in the house at which the air switches from exhausting to infiltrating. The better air sealed the house is, the closer to the floor this plane will be.

    I'm just wondering if you can really tell much from waving a stick of incense around or if I need to generate some serious smoke and pressurize the place to see where the holes really are.

    I've put plastic over the areas that had raw fiberglass for the ceiling. That should help. It'll be better than the years when *all* I had was clapboards on the outside and plastic on the inside--no insulation, no sheathing, no drywall. As Fred or someone else said before, given the choice of only a roll of plastic or a truckfull of FG, I'll take the plastic, please. It actually did a pretty good job!

    As to the thimble, let me clarify that it's a clay thimble into a clay liner in a cinder block chimney. The thimble is isolated from flamables by passing through a brick surround that extends 12 inches in all directions. Do you think there is any danger of fire if I bridge the 1/4 inch gap between the metal stovepipe and the inside of the thimble with refractory cement? The Pipe is still a foot away through solid masonry from any framing.

    Shivering in Cooperstown

    Steve

    1. Guest_ | Jan 02, 1999 08:06am | #6

      *Hi there Fred,Glad you got a chance to read this.How's the book coming? I'm waiting with (frozen) baited breath!It's twelve below zero, and I'm heating 1700sf to 60 degrees.Actually I'm not doing too bad. I've got my Consolidated Dutchwest Extra Large Federal Woodstove fired up (rated at 55k BTU/hr, though I doubt it's hitting half of that) and now the oil burner is only cycling on for about 90 seconds minutes every twelve minutes or so, or about 8 minutes an hour w/a 1.35 GPH nozzle on the burner.Of course without that woodstove going it's got to be sucking twice that much at least.I was hoping that you would tell me my NPP is so low because my house is really tight as a drum! Oh well, let's make it a New Years Resolution to get it there for next year. I guess one reason it could be low is because the cellar/crawlspace is on a Central New York unmortared fieldstone foundation that is pretty much transparent as far as air goes. Actually that's not true, the cellar half is mortared pretty tight, but it is open to the sieve that is the crawlspace, There is also the matter of that chimney that runs from the cellar floor to 40 feet up, with the large airspace all around it at all penetrations. Would this large "flue" in the cellar help pull the NPP down? If it makes any difference, The chase runs outside of the thermal envelope where it goes through the living spaces, but it's open to the cellar at the bottom.Where would be the best place to seal this chimney penetration? It would be easiest where it passes through the first floor ceiling, as there is very irregular fieldstone wall around it where it penetrates the cellar ceiling. It's very hard for me to read my poly on the windows because I stretch it pretty tight, but it doesn't really seem to bow in unless the wind blows.Anyway, thanks for the note.Steve

  5. Patrick_M. | Jan 02, 1999 10:35pm | #7

    *
    Hi Steve

    Be glad your not about 200 miles north, it's 25 below here. You've got Fred on board now, and he and I have already had a 'tilt' over this but I think you make a huge mistake discounting the effectiveness of F/g. Given the choice of a truck full of f/g and a roll of poly I'd take both and be warmer for the combination. It may not be as amazingly wonderful as dense pack cells but don't believe the crap that it's 'worse than nothing'. Fred's credibility took a nosedive for me when I read him promoting that idea back in the fall. I also carefully read his rationale, and about how he makes big bucks crushing f/g with blown in cells and turns uninhabitable buildings into owner happy comfort zones, but I too have taken igloos and turned them into snug abodes, my own and others, and I've done it with f/g. and while his may be more energy efficient than mine it still puts the lie to the idea that f/g is useless as an insulating material. In a perfect world etc.,. . . but it sounds like your current world is a might short of perfection, and in desperate need of some quick insulation. A sheet of poly might save you 5 or 10 degrees, but add some f/g behind it and you'll start to feel warm. Notwithstanding all the installation requirements needed to maximize it's effect, and noting the rhetoric about suspect R values, it's still waaay better than nothing, and you can always toss it later when your structure is tight enough to allow cells to be blown in.

    Snug at 25 below in a house stuffed with f/g and covered with poly, with an acceptable oil heating bill too!! With room for improvement of course.

    Hunkering down to withstand the barrage,

    Patrick

  6. Guest_ | Jan 06, 1999 07:56pm | #8

    *
    Hi Fred,

    I just went down in the basement with my incense to the bottom of the chimney chase (which begins at the cellar ceiling), and the smoke sometimes went up the chase and sometimes blew back at me. It's not perfectly still outside however.

    Let me elaborate on the placement of this chase. It's boxed into the corner of the house. There is about a foot between the chimney and the exterior walls, and about two inches between the chimney and the interior walls that I've boxed it in with. The thermal envelope goes on the walls that are between the chimney and the interior space, leaving the chimney essentially outdoors, but with a hole to the cellar at its base.

    I'm not sure what the expected behavior of this hole would be. Since the hole is at cellar ceiling level to the out-of-doors, I would expect it to suck air since it's below the neautral pressure plane. But I would also expect it to blow out anytime there is heat being generated in the cellar, such as by the boiler, the hot water heater, and the exposed heating pipe runs. *BUT* The cellar ceiling is very porous in relation to the living space above, as well as to the adjacent crawlspace, which is also very porous to the ouside air and to living space above it.

    What I live in is essentially an upside down box. The bottom of it is pretty wide open but the top and sides are somewhat sealed. The Thermal envelope has no bottom. It stops at the sills. It holds heat pretty well until the wind blows, not unlike going outside in a long bathrobe on a cold day--your legs stay pretty warm until a breeze comes along, endangering the warmth of your plumbing!

    Any further thoughts?

    Steve

  7. bump_(nm) | Jan 07, 1999 05:37am | #9

    *
    bump

  8. Guest_ | Jan 07, 1999 06:45am | #10

    *
    Hello all you weatherization folks,

    I've just been running around the house with an incense stick trying to figure out where to best apply some slapdash air sealing to help slow the rush of oil to the oil burner during this Upstate NY cold snap.

    It's very hard to read the swirling smoke.Can you help me make sense of this and recommend some options?

    It's the first floor only of a two story building.The second story is gutted and wide open to the elements in many places, so the first floor ceiling is essentially the roof for now. One room has plastic sheeting for a ceiling with no insulation. Another room is drywalled with FG between the drywall and the upstairs floorboards. Two other rooms are insulated with FG in the ceiling, but have no covering (no drywall or plastic sheeting) and yet one other room has drywall ceiling but no insulation at all.

    There is a piece of 1/2 inch particle board laying over the hole at the top of the staircase, and where there are visible gaps, some smoke goes throgh there, but not at nearly the rate I expected.

    Many of my "windows" consist of a single sheet of plastic.

    By all rights I should see the smoke flying out all over the place, but I don't. It doesn't seem to rush out of anywhere except the gap between the woodstove pipe and the chimney thimble.

    I expected to see it flying out of the four recessed (IC) cans. Not so. Losing some there, but not tons.

    I expected to see it disappearing around the FG in the rooms where it is exposed, but it's not, really.

    I am unable to crack the windows to do the sash test, because I have plastic over the exterior of them. But the chimney thimble is about 2 feet below the ceiling, and the smoke goes out there. When I open an exterior door a crack, the smoke goes out down to about a foot above the doorknob, then starts blowing in below that. Of course it's not super still outside, so who's to say how much is wind driven in either direction.

    Cold air of course pours in from various holes in the flooring that are above both the cellar and a freezing cold crawlspace.

    Many questions:

    How can my Neutral Pressure Plane be so low with what ought to be so many leaky spots?

    Where should I start? Plastic over the areas with raw (Kraft faced) FG showing?

    What should I use to seal the gap around the stovepipe and thimble?

    I would love to hear anyone's take on this.

    Steve Zerby

    1. Guest_ | Jan 01, 1999 11:03pm | #1

      *bump

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

Video Shorts

Categories

  • Business
  • Code Questions
  • Construction Techniques
  • Energy, Heating & Insulation
  • General Discussion
  • Help/Work Wanted
  • Photo Gallery
  • Reader Classified
  • Tools for Home Building

Discussion Forum

Recent Posts and Replies

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

Up Next

Video Shorts

Featured Story

Making the Move to Multifamily

A high-performance single-family home builder shares tips from his early experience with two apartment buildings.

Featured Video

A Modern California Home Wrapped in Rockwool Insulation for Energy Efficiency and Fire Resistance

The designer and builder of the 2018 Fine Homebuilding House detail why they chose mineral-wool batts and high-density boards for all of their insulation needs.

Related Stories

  • Podcast Episode 692: Introduction to Trade Work, Embodied Carbon, and Envelope Improvements
  • FHB Podcast Segment: Embodied Greenhouse Gas Emissions and the Building Codes
  • Old Boots Learn New Tricks
  • Install Denim Insulation Like a Pro

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.

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Fine Homebuilding Magazine

  • Issue 332 - July 2025
    • Custom Built-ins With Job-Site Tools
    • Fight House Fires Through Design
    • Making the Move to Multifamily
  • Issue 331 - June 2025
    • A More Resilient Roof
    • Tool Test: You Need a Drywall Sander
    • Ducted vs. Ductless Heat Pumps
  • Issue 330 - April/May 2025
    • Deck Details for Durability
    • FAQs on HPWHs
    • 10 Tips for a Long-Lasting Paint Job
  • Issue 329 - Feb/Mar 2025
    • Smart Foundation for a Small Addition
    • A Kominka Comes West
    • Making Small Kitchens Work
  • Issue 328 - Dec/Jan 2025
    • How a Pro Replaces Columns
    • Passive House 3.0
    • Tool Test: Compact Line Lasers

Fine Home Building

Newsletter Sign-up

  • Fine Homebuilding

    Home building tips, offers, and expert advice in your inbox.

  • Green Building Advisor

    Building science and energy efficiency advice, plus special offers, in your inbox.

  • Old House Journal

    Repair, renovation, and restoration tips, plus special offers, in your inbox.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters

Follow

  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X
  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X

Membership & Magazine

  • Online Archive
  • Start Free Trial
  • Magazine Subscription
  • Magazine Renewal
  • Gift a Subscription
  • Customer Support
  • Privacy Preferences
  • About
  • Contact
  • Advertise
  • Careers
  • Terms of Use
  • Site Map
  • Do not sell or share my information
  • Privacy Policy
  • Accessibility
  • California Privacy Rights

© 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.

  • Home Group
  • Antique Trader
  • Arts & Crafts Homes
  • Bank Note Reporter
  • Cabin Life
  • Cuisine at Home
  • Fine Gardening
  • Fine Woodworking
  • Green Building Advisor
  • Garden Gate
  • Horticulture
  • Keep Craft Alive
  • Log Home Living
  • Military Trader/Vehicles
  • Numismatic News
  • Numismaster
  • Old Cars Weekly
  • Old House Journal
  • Period Homes
  • Popular Woodworking
  • Script
  • ShopNotes
  • Sports Collectors Digest
  • Threads
  • Timber Home Living
  • Traditional Building
  • Woodsmith
  • World Coin News
  • Writer's Digest
Active Interest Media logo
X
X
This is a dialog window which overlays the main content of the page. The modal window is a 'site map' of the most critical areas of the site. Pressing the Escape (ESC) button will close the modal and bring you back to where you were on the page.

Main Menu

  • How-To
  • Design
  • Tools & Materials
  • Video
  • Blogs
  • Forum
  • Project Guides
  • Reader Projects
  • Magazine
  • Members
  • FHB House

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Popular Topics

  • Kitchens
  • Business
  • Bedrooms
  • Roofs
  • Architecture and Design
  • Green Building
  • Decks
  • Framing
  • Safety
  • Remodeling
  • Bathrooms
  • Windows
  • Tilework
  • Ceilings
  • HVAC

Magazine

  • Current Issue
  • Past Issues
  • Magazine Index
  • Subscribe
  • Online Archive
  • Author Guidelines

All Access

  • Member Home
  • Start Free Trial
  • Gift Membership

Online Learning

  • Courses
  • Project Guides
  • Reader Projects
  • Podcast

More

  • FHB Ambassadors
  • FHB House
  • Customer Support

Account

  • Log In
  • Join

Newsletter

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Follow

  • X
  • YouTube
  • instagram
  • facebook
  • pinterest
  • Tiktok

Join All Access

Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features.

Start Your Free Trial

Subscribe

FHB Magazine

Start your subscription today and save up to 70%

Subscribe

Enjoy unlimited access to Fine Homebuilding. Join Now

Already a member? Log in

We hope you’ve enjoyed your free articles. To keep reading, become a member today.

Get complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine.

Start your FREE trial

Already a member? Log in

Privacy Policy Update

We use cookies, pixels, script and other tracking technologies to analyze and improve our service, to improve and personalize content, and for advertising to you. We also share information about your use of our site with third-party social media, advertising and analytics partners. You can view our Privacy Policy here and our Terms of Use here.

Cookies

Analytics

These cookies help us track site metrics to improve our sites and provide a better user experience.

Advertising/Social Media

These cookies are used to serve advertisements aligned with your interests.

Essential

These cookies are required to provide basic functions like page navigation and access to secure areas of the website.

Delete My Data

Delete all cookies and associated data