Mini-Crawl Spaces between City Row-Home's Conditioned Stories

I have been finding more row-homes with 2' -3' sub-floors with ducts and piping running through them, that are usually opened to the outdoors (exterior walls & bypasses) and run the width & length of the home. I am wondering if anyone has ever addressed these spaces? Thanx, Bob

Tags: City, Homes, Mini-Crawl, Row, Spaces

Views: 92

Reply to This

Replies to This Discussion

As a FYI, HELP is going forward with this retrofit, via dense packing all the exterior rim cavity areas between stories and will give an update when completed... (NOTE: with Cellulose of course) Thanx

Do you mean crawl spaces below the lowest floor level? or do you mean a 2-3 ft. space between floors?

What do you mean by "opened to the outdoors" and "bypasses"?

If you are talking about crawl spaces, then cellulose is not recommended at grade due to the potential for absorbing moisture.

Hi Brad, This is a space between the 1st floor ceiling and the 2nd floor floor. The area is 12' * 28' & is being used to run the duct work and water pipes to the home. Note: the HVAC is @ the rear 2nd floor. It is really deep with ~ 3' near the HVAC. I actually found another home like this shortly afterward and that is making me wonder how many of the retrofit opportunities have I missed in my 33 years? The rear sub-crawl has 3 exterior wall surrounding it and the middle has 1 long side wall to the exterior and it's opposite is buffered by a neighbor.

My thought now is to dense pack any mini sub-floor perimeter walls with Cellulose, into home about 2'. I feel by doing this I can bring the whole sub-floor back inside the home (for it is outside now due to ballooned walls and the exterior touching sills). The duct work will also come inside and though I will be bringing the ducts from a non-conditioned to a conditioned area... I am not trying to enter that data toward Total Pay-Back... 

Any other thoughts?

Also, To:
"What do you mean by "opened to the outdoors" and "bypasses"?"

This is opened to the Outdoors through open walls and the CFM's were as high as some McMansions HELP has done. Bypasses to me are Chase-ways to others.

Thanx for the Reply! Bob


 Now I am really confused. The 2nd photo shows what appears to be a typical 2x10 or 12" joist bay, with what appears to be sheetrock below and plywood subfloor above, with what appears to be mold on some of the surfaces. This is commonly called a "panned joist", which is using a joist bay to duct heated air from (or to) a furnace. This oftens results in air leakage to the exterior, where the joists meet the exterior walls.

If that is the case, then dense-packing the joist bays where they meet the exterior wall will greatly reduce air leakage and save energy. I do not see where it is feasible to do that. The exterior is all brick or mortar and would require an ~3" hole on the exterior, at every joist bay. There may be a possibility to do that from the interior by drilling through a sheetrock ceiling. The method is called "bag and blow". When done from the exterior, a bag (we use used feed or grain bags) a bag that air can flow through is pushed into the joist bay with the end of the dense-pack hose, that is lightly secured to the hose. The bag is pumped with cellulose until it is blocking the entire joist bay. The hose can then be pulled out of the bag and the space between the bag and exterior wall is then dense-packed (typ. 1-2 ft.of joist bay).

I am going to take a wild guess that the 3 ft. "chases" are boxed in areas to carry duct work or act as ducts. I cannot see how it would be feasible to dense-pack such a chase with a duct running through it.

Hi Brad sorry to confuse, but difficult to put in words, but yes going in from the inside 1st floor ceiling @ exterior wall and since the mini-crawl is 2' deeps (& may have "split layers @ 12" each?) (see pic from @ HVAC) I plan on adding 24" FG Batt as a backer about 2' from the exterior wall. I should of added some more strangeness which is the exterior walls are 10" - 14" and the home has ballooned walls and HIGH Air Leakage. The stories comfort problems are inverted too, being 2nd cold cold Winter and 1st hot hot and then it flops for Summer...

The bag idea sounds good also... Thanx and any ideas would HELP also,




Forum Discussions

Exterior green cladding

Started by Luis Hernandez in General Forum Apr 12. 0 Replies

Faces & Places of HPC19

Started by Diane Chojnowski in General Forum Apr 5. 0 Replies

high rise humidity

Started by Steve Nations in HVAC. Last reply by Dennis Heidner Apr 3. 7 Replies

Follow the action at #HPC19

Started by Diane Chojnowski in General Forum Apr 2. 0 Replies

Unvented Roof Assembly

Started by Patrick Michaelyan in General Forum. Last reply by Wallacebastien Mar 30. 6 Replies

Technology and Customer Service

Started by Kelly Caplenas in General Forum. Last reply by Franco Oyuela Mar 25. 1 Reply

Latest Activity

Joe Hughes posted an event

IAQ Radio - Episode 543 - Joe Spurgeon, PhD - FLASHBACK FRIDAY - Mold Inspection & Sampling : Is it time to rethink your approach? at Online

April 19, 2019 from 12pm to 1pm
Joe C. Spurgeon, Ph.D.Mold Inspection & Sampling : Is it time to rethink your…See More
6 minutes ago
Joe Hughes posted a blog post

Eugene C. Cole, DrPH – Research to Practice: Water Damage, Sewage, Mold & Public Health

Iaqradio+ Episode 542Eugene C. Cole, DrPHResearch to Practice: Water Damage, Sewage, Mold &…See More
18 minutes ago
Emily Ambrose's blog post was featured
33 minutes ago
Corbett Lunsford's video was featured

Chemistry and Building Performance with HOMEChem's Dr. Richard Corsi

Dr. Corsi has been experimenting with indoor chemistry for decades, and his findings are NOT what you'd expect. Listen to the man. Learn more at:
3 hours ago
Diane Chojnowski posted a blog post
4 hours ago
Emily Ambrose posted a blog post
4 hours ago
Matt Worthy posted photos
14 hours ago
Brandon Price replied to Brandon Price's discussion For Sale: Minneapolis Blower Door, Duct Blaster and 2xDG-700. in the group Energy Auditing Equipment for Sale, Trade or to Purchase
14 hours ago

© 2019   Created by Home Performance Coalition (HPC)   Powered by

Badges  |  Report an Issue  |  Terms of Service