Foundation Vents In Addition - Page 2 - General Discussion - Contractor Talk

Foundation Vents In Addition

 
Thread Tools Search this Thread Display Modes
Old 04-29-2019, 10:35 AM   #21
Pro
 
nickko's Avatar
 
Trade: remodeling-cabinet maker
Join Date: Nov 2012
Location: western pa
Posts: 366
Rewards Points: 783

Re: Foundation Vents In Addition


Quote:
Originally Posted by greg24k View Post
If you take out the foundation vents you need mechanical ventilation.

R408.3 Unvented crawl space.
Ventilation openings in under-floor spaces specified in Sections R408.1 and R408.2
shall not be required where the following items are provided:
1. Exposed earth is covered with a continuous Class I vapor retarder. Joints of the vapor retarder shall overlap by 6 inches (152 mm) and shall be sealed or taped. The edges of the vapor retarder shall extend not less than 6 inches (152 mm) up the stem wall and shall be attached and sealed to the stem wall or insulation.

2. One of the following is provided for the under-floor space:

2.1. Continuously operated mechanical exhaust ventilation at a rate equal to 1 cubic
foot per minute (0.47 L/s) for each 50 square feet (4.7 m2) of crawl space floor area, including an air pathway to the common area (such as a duct or transfer grille), and perimeter walls insulated in accordance with Section N1102.2.11 of this code.

2.2. Conditioned air supply sized to deliver at a rate equal to 1 cubic foot per minute
(0.47 L/s) for each 50 square feet (4.7 m2) of under-floor area, including a return air pathway to the common area (such as a duct or transfer grille), and perimeter walls insulated in accordance with Section N1102.2.11 of this code.
I am not sure if code addresses crawl space liners but it made a big difference in my crawl space. I have ductwork in my crawl space and it would condensate in the humid summer months. After the crawl space liner and closing up the vents i have no condensation on my ducts in the summer. I never did understand letting warm moist air into a cool crawl space. Do a search on crawl space liners and it makes sense.

nicko
__________________
"Quality work for those who know the difference"
nickko is offline  

Warning: The topics covered on this site include activities in which there exists the potential for serious injury or death. ContractorTalk.com DOES NOT guarantee the accuracy or completeness of any information contained on this site. Always use proper safety precaution and reference reliable outside sources before attempting any construction or remodeling task!

   

Advertisement

 

Old 04-29-2019, 06:41 PM   #22
Always Learning
 
overanalyze's Avatar
 
Trade: Builder/Remodeler
Join Date: Dec 2010
Location: NW Ohio
Posts: 8,089
Rewards Points: 702

Re: Foundation Vents In Addition


Quote:
Originally Posted by builditguy View Post
What we do for the most part.



We put down visqueen, then pour concrete in all crawlspaces. We only pour it about 3" thick and it only gets a bull float finish.

Then spray foam the walls. Lately they also get a layer of fiberglass blanket over the top, due to code.
I think the blanket covering the foam is due to the flame spread of the spray foam. My understanding was it wasn't required if there wasn't an ignition source in the space like a furnace or gas line but maybe I interpreted it wrong.
__________________
It is what it is...now fix it.
overanalyze is offline  
Old 05-01-2019, 06:28 AM   #23
Pro
 
builditguy's Avatar
 
Trade: Carpentry
Join Date: Nov 2013
Location: Missouri
Posts: 2,120
Rewards Points: 1,322

Re: Foundation Vents In Addition


Quote:
Originally Posted by overanalyze View Post
I think the blanket covering the foam is due to the flame spread of the spray foam. My understanding was it wasn't required if there wasn't an ignition source in the space like a furnace or gas line but maybe I interpreted it wrong.
I believe you are right about the flame spread. I don't know about the ignition source. The spray foam company I use won't do, only foam.

Could be their own company policy, to charge a little more, or to protect them from liability.
I know a homeowner sued the GC on a house, a couple years ago. All of the subs were included in the suit. They were one of the only companies that were found innocent, because they had done everything by the book. Maybe they are gun shy now.

Advertisement

builditguy is offline  
The Following User Says Thank You to builditguy For This Useful Post:
overanalyze (05-01-2019)


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Crawlspace access to addition from main house jjperry84 Construction 10 03-02-2017 02:59 PM
Retrofit Foundation Vents? miillersickness Carpentry 0 12-26-2012 04:26 PM
Provisions for future concrete slab addition txgencon Concrete & Paving 2 03-30-2011 08:11 PM
Waterproofing A Foundation Wall With No Access dcbuilder Construction 16 01-31-2011 06:52 PM
Truss uplift or foundation movement NailBender2 Carpentry 6 01-05-2011 05:22 PM

Join Now... It's Fast and FREE!

I am a professional contractor
I am a DIY Homeowner
Drywall Talk is for
PROFESSIONAL CONTRACTORS ONLY!

At DrywallTalk.com we cater exlusivly to professional contractors who make their living as a contractor. Knowing that many homeowners and DIYers are looking for a community to call home, we've created www.DIYChatroom.com DIY Chatroom is full of helpful advices and perfect for DIY homeowners.

Redirecing in 10 seconds
No Thanks
terms of service

Already Have an Account?