I am convinced that a client of mine is the victim of a shoddy crawl space ceiling insulation job, and that he should have it done right. He too in convinced.

So, the question is how best to address it. 

The crawl space is only 200 sf, located below a single-room addition, with ducts in the floor. There are plenty of penetration through the floor and the sill boxes. Air is the least of our worries (it's the darn critters he wants to keep out, and reduced leakage is a bonus). The existing faced fiberglass batts (R-19) are showed into between the joists, with the kraft facing in the wrong direction. The batt insulation is only 5 years old, and it's condition has not been compromised. 

The following is my proposed approach to the problem. Remove the existing batt insulation, apply a flash coat of closed-cell spray foam, cut batts to fit properly, install wire supports to keep batts flush with floor, and install a layer of house wrap to underside of joists to protect batt insulation. Sound like a winner to you pros?

Thanks in advance!

Views: 690

Reply to This

Replies to This Discussion

Considering the small size of the job, is there a minimum number that the insulation guy is going to charge for the job? I would determine that with different comparisons of thicknesses of the foam.

Does the crawl space have a floor? Is it ventilated? Do you have moisture coming up? 

Hello Bruce.

Slab floor. Ventilated like you've never seen before. There are large openings at the perimeter for easy access to the space. The accesses are closed up with steel gates (of the aesthetic kind), so sealing up the space at the walls is not an option. No moisture coming up.

No minimum charge for job, just "get it right." My goal is to get the homeowner the best bang for his buck. This is why I'd like to get the flash coat of foam (about an inch) to the floor.

Thanks Bruce.

If cost isn't an option, why not go with a full thickness of foam and get rid of the f/g? Eventually, moisture will gather in the f/g, wire supports will fail and the homeowner will have a problem again.

You raise a very legit point Bruce, but then we are also talking about a job cost near $2,000 versus $600. Also, this means that we'd be throwing out good insulation, and I hate "wasting" things.

Also, won't the house wrap serve to significantly reduce the moisture build-up in the fiberglass?

I'm sure the house wrap will reduce the moisture penetration substantially, as long as it is installed properly. But I don't know if it will prevent all moisture penetration over a period of years. Especially if there are critters involved. Any chance of bats nesting under there? I am flying blind here a bit, but if the h/o paid for decorative iron gates for his crawl space, I'm not sure that he would flinch at an informed proposal for foam for an additional $1400.00.

If I were you, I would lay down options for him to decide, and tell him what you would do if it were your home, and why; while setting aside the cost considerations. People are not always easy to read, and I have often been surprised when homeowners bite on quality over cost after a good sales presentation. Who knows, he may like the foam so much that he calls you back to do the whole attic next year.  

Good points Bruce.

I'll give it a shot.

One last issue: the ducts in the floor. I was going to have rigid insulation installed below the flex duct (the ducts sit just above the underside of the floor joists). Any suggestions? Thanks!

That makes sense to me, I would hit the rigid foam with the foam as you pass by, mainly to seal the edges and have a uniform finish.

Here's a great article for your resource: http://www.greenbuildingadvisor.com/blogs/dept/musings/building-unv...

Also, will there be any negative fumes emitted from the spray foam application?  http://www.greenbuildingadvisor.com/community/forum/green-products-...

Thanks for the article Carlos.

The new product I'm using is supposed to emit no VOCs that would be considered negative fumes. In the past that has been one of my main concerns with respect to spray foam.

Patrick

Sounds like a winner to me, you can skip the wire supports the house wrap should support the insulation just fine. Another option would be to skip the fiberglass and spray foam, and fasten ridgid foam (thermax) to the joists then dense pack with cellulose. The foam and dense pack is just a sweet way to go. You reduce the thermal bridging of the joists, get a good air seal, and have a nice finished R-value.

Cory, the approach you mention is the balls! I typically do just what you recommend. In this case I want to avoid tossing the fiberglass, and the homeowner is concerned with accessing the pipes, ducts, etc.

Thanks for the advice Cory!
Cory, for future reference, when you go the rigid and dense-pack cellulose route do you also hit the main penetrations through the floor with foam sealant, or would you just consider that over-redundant?

And, same question with respect to fiberglass and rigid (vs. cellulose and rigid).

Patrick

RSS

Forum Discussions

Why is Air Sealing Important?

Started by Cameron Home Insulation in General Forum 1 hour ago. 0 Replies

Greetings :)

Started by Dennis in General Forum. Last reply by Diane Chojnowski 17 hours ago. 2 Replies

Electro Magnetic Fields (EMF)

Started by Barry L NewDelman in General Forum. Last reply by Brad Cook 17 hours ago. 12 Replies

Zehnder Comfopipe vs. rigid pipe

Started by Alan Lehman in HVAC yesterday. 0 Replies

Follow the action at HPC 2018

Started by Diane Chojnowski in General Forum yesterday. 0 Replies

Latest Activity

Cameron Home Insulation posted a discussion

Why is Air Sealing Important?

Hello guys, Tell me, Why is Air Sealing Important? Share your views.Why is Air Sealing Important?See More
1 hour ago
Ryan T De La Rosa posted a blog post

Home Energy Savings In An Unlikely Place

When thinking of the best way to save mother nature, it's likely that the last thing on your mind…See More
8 hours ago
Taylor Joseph Mckay replied to Taylor Joseph Mckay's discussion Seeking to Purchase Blower Door in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"please shoot me an email taylor.joseph.mckay@gmail.com"
11 hours ago
Diane Chojnowski replied to Dennis's discussion Greetings :)
"Welcome Dennis! Great to have you join us! "
17 hours ago
Brad Cook replied to Barry L NewDelman's discussion Electro Magnetic Fields (EMF)
"Whoa! EMFs are everywhere, but they are not all equal. The characteristics of EMFs varies very much…"
17 hours ago
Ben Thompson replied to Taylor Joseph Mckay's discussion Seeking to Purchase Blower Door in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"Hi Taylor.  I have a Minneapolis Blower Door set up for sale. DG-700 manometer was factory…"
17 hours ago
Arn McIntyre replied to Taylor Joseph Mckay's discussion Seeking to Purchase Blower Door in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"Taylor I have item described below for sale.  Pictures are posted in Equipment for…"
17 hours ago
Taylor Joseph Mckay added a discussion to the group Energy Auditing Equipment for Sale, Trade or to Purchase
Thumbnail

Seeking to Purchase Blower Door

Hi, I'm getting into energy audits and am looking to save a few bucks on picking up a used blower…See More
18 hours ago
Taylor Joseph Mckay joined allen p tanner's group
Thumbnail

Energy Auditing Equipment for Sale, Trade or to Purchase

Discuss the pros and cons of the equipment you are interested in prior to purchase. Post equipment…See More
18 hours ago
Sandra James replied to Barry L NewDelman's discussion Electro Magnetic Fields (EMF)
"I am quite interested in how EMF can cause health issues.  There is no question that too much…"
19 hours ago
Sandra James replied to Dennis's discussion Greetings :)
"Hello There, I am new as well. Hoping to learn new things through the course of this time on this…"
19 hours ago
Profile IconJames Sabal, Ethan Foley and Katelyn Haas Conrad joined Home Energy Pros Forum
19 hours ago
Alan Lehman posted a discussion

Zehnder Comfopipe vs. rigid pipe

Hello All,I have installed few Zehnder systems and I am not sure if my rep is giving me the info I…See More
yesterday
Diane Chojnowski posted a discussion
yesterday
Brett Little's 2 events were featured
yesterday
Profile IconSandra James, arthur wilson, Nolan and 4 more joined Home Energy Pros Forum
yesterday
Landon added a discussion to the group Energy Auditing Equipment for Sale, Trade or to Purchase
Thumbnail

BRAND NEW: Fantastic Software for Retrotec

I purchased a new blower door system from retrotec and it came with the fantestic software.…See More
Monday
CEE posted a blog post
Monday
CEE's blog post was featured
Monday
Brett Little posted events
Saturday

Photos

  • Add Photos
  • View All

© 2018   Created by Home Performance Coalition (HPC)   Powered by

Badges  |  Report an Issue  |  Terms of Service