Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Building & Construction

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-25-2011, 09:20 AM   #1
Member
 
Join Date: May 2008
Location: MA
Posts: 36
Share |
Default

Basement Finish/installation


We are in the process of finishing our basement and we had some questions in regards to insulation.

Our basement is a walk-out basement, the 2x6 wall (non-concrete) is located in the back of house. I noticed that when we purchased the house built 5 years ago, the insulation on this wall was fiberglass unfaced batts with no vapor. I recently removed the unfaced batts for running electrical (we have permits) and noticed that the outside wall wood under the batts was moist/wet in some areas.

It appears the entire wall (walk-out basement wall) is in the same condition, i think mold may be in some areas, as there are some black smudges. There appears to be no plumbing leaks, no outside holes, etc?

What would be the proper way to insulate this type of wall? What could be causing the 2x6 walls to get moisture?

Thank You


Last edited by ddave23; 10-25-2011 at 09:43 AM.
ddave23 is offline   Reply With Quote
Old 10-25-2011, 11:35 AM   #2
Retired from the grind
 
gregzoll's Avatar
 
Join Date: Dec 2006
Location: Midwest - Central Illinois
Posts: 14,105
Default

Basement Finish/installation


You won't be able to, until you stop the water intrusion from outside. That means checking gutters and downspouts, slope of earth to push water away. The best way of insulating, is XPS, not fiberglass batts.

__________________
Ren: Now listen, Cadet. I've got a job for you. See this button? Ren: Don't touch it! It's the History Eraser button, you fool! Stimpy: So what'll happen? Ren: That's just it. We don't know. Maybe something bad, maybe something good. I guess we'll never know, 'cause you're going to guard it. You won't touch it, will you?
gregzoll is offline   Reply With Quote
Old 10-25-2011, 11:46 AM   #3
Member
 
Join Date: Jul 2011
Posts: 37
Default

Basement Finish/installation


The moisture is likely a result of condensation. Do a Google search for "Basement Insulation Systems" and the first .pdf file is one you want to review. My understanding is that this article primarily deals with concrete walls and not an exterior wood framed wall. Nometheless, I think it will be helpful. Personally, I would probably avoid fiberglass unless you can maybe install 2-inch XPS or 2-inch polyiso (directly against plywood), then follow that up with 3.5 inches fiberglass batts. That may not work either, but it's a starting point. Oh yeah, usually best to stay away from vapor barrier. That article does a nice job summarizing the why.
kmachn is offline   Reply With Quote
Old 10-25-2011, 12:04 PM   #4
Retired from the grind
 
gregzoll's Avatar
 
Join Date: Dec 2006
Location: Midwest - Central Illinois
Posts: 14,105
Default

Basement Finish/installation


Quote:
Originally Posted by kmachn View Post
The moisture is likely a result of condensation. Do a Google search for "Basement Insulation Systems" and the first .pdf file is one you want to review. My understanding is that this article primarily deals with concrete walls and not an exterior wood framed wall. Nometheless, I think it will be helpful. Personally, I would probably avoid fiberglass unless you can maybe install 2-inch XPS or 2-inch polyiso (directly against plywood), then follow that up with 3.5 inches fiberglass batts. That may not work either, but it's a starting point. Oh yeah, usually best to stay away from vapor barrier. That article does a nice job summarizing the why.
Google will return fud. The best info is the building science website at http://www.buildingscience.com

There is no way to tell that it is condensation, unless they place plastic wrap taped against the foundation. Due to the fiberglass was damp on the concrete side, that right there tells you that there was water intrusion from the outside.
__________________
Ren: Now listen, Cadet. I've got a job for you. See this button? Ren: Don't touch it! It's the History Eraser button, you fool! Stimpy: So what'll happen? Ren: That's just it. We don't know. Maybe something bad, maybe something good. I guess we'll never know, 'cause you're going to guard it. You won't touch it, will you?
gregzoll is offline   Reply With Quote
Old 10-25-2011, 12:15 PM   #5
Member
 
Join Date: May 2008
Location: MA
Posts: 36
Default

Basement Finish/installation


Thank you both for the links...I will check them out.

The wall that is getting wet is the outside wood siding wall (basement walk-out wall). When i remove the unfaced batts, the wood is wet.

We have checked gutters and slope on the outside, and have not noticed any thing out of norm...I was wondering if it was condensation?
ddave23 is offline   Reply With Quote
Old 10-25-2011, 12:18 PM   #6
Member
 
Join Date: Jul 2011
Posts: 37
Default

Basement Finish/installation


Quote:
Originally Posted by gregzoll View Post
Google will return fud. The best info is the building science website at http://www.buildingscience.com

There is no way to tell that it is condensation, unless they place plastic wrap taped against the foundation. Due to the fiberglass was damp on the concrete side, that right there tells you that there was water intrusion from the outside.
The .pdf that is the first result on "Basement Insulation Systems" on a Google search is from the Building Science Corporation. Maybe it would be easier to just link to the article... http://www.eere.energy.gov/buildings...s/db/35017.pdf

It is true that one can not be sure that it is condensation. My understanding from the original post is that there is "no concrete", meaning it is an exterior, wood-framed basement wall for the walkout basement. Unless they put dirt directly against this wood wall (which is unlikely) then it is probably not water intrusion from a ground source or water runoff. However, it is possible that it could be rain water penetrating the plywood sheathing. Condensation can accumulate on the plywood side of this wall since it doesn't have a vapor barrier. It is possible that it could be the surface where the cold outside air would meet the warm inside air.
kmachn is offline   Reply With Quote
Old 10-26-2011, 11:46 PM   #7
Registered User
 
Join Date: Mar 2009
Posts: 9,968
Default

Basement Finish/installation


Do you have vented cladding or insulating sheathing on the exterior wall?

Sounds like you only have unfaced f.g. batt insulation without the required vapor retarder facing paper with high humidity in the basement. Your Zone 5 requires it, unless as I said above.
High basement humidity or other can cause the wetting, reducing the insulation by 60-70%: http://www.nrc-cnrc.gc.ca/eng/ibp/ir...ling-heat.html

Gary
__________________
If any ads are present in my answer above, I do not condone/support/use the product or services listed, they are there against my permission.
Gary in WA is offline   Reply With Quote
Old 10-27-2011, 07:26 AM   #8
Member
 
Join Date: May 2008
Location: MA
Posts: 36
Default

Basement Finish/installation


Thank you for the info...good stuff..

I think the basement does have high humidity, I am in the process of getting a de-humidifier. I do not believe it is a water issue from the outside, but I cannot be for sure.

It may be moisture from the concrete floor, as on the same wall, past the floor joists, when i remove the insulation, I do not see any mold or does not appear/feel wet. The moist wood only seems to be the above grade walls in the basement. i can see the first floor wall (same wall above the joist) is not wet/mold.
ddave23 is offline   Reply With Quote
Old 10-27-2011, 08:44 AM   #9
Retired from the grind
 
gregzoll's Avatar
 
Join Date: Dec 2006
Location: Midwest - Central Illinois
Posts: 14,105
Default

Basement Finish/installation


First step is to get everything off of the walls, so that the dehumidifier can do its initial job. Then when you go to finish, make sure that the hvac system is properly ducted to help keep the space conditioned. If done correctly, there should be no degree difference between the finished basement space and the main living space.

While you are at it, get a humidistat to monitor the space. You can get remote sender units, so that you can read it from the main floor.

__________________
Ren: Now listen, Cadet. I've got a job for you. See this button? Ren: Don't touch it! It's the History Eraser button, you fool! Stimpy: So what'll happen? Ren: That's just it. We don't know. Maybe something bad, maybe something good. I guess we'll never know, 'cause you're going to guard it. You won't touch it, will you?
gregzoll is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Basement sewer smell jturk1000 Plumbing 1 09-20-2011 12:59 PM
Wet basement - don't know where to start konradsa Building & Construction 17 09-20-2011 10:08 AM
Remodeling basement: Moist foundation gordonf238 Building & Construction 8 04-25-2010 06:50 PM
Basement Renovation Project Howdy Electrical 6 03-13-2008 11:07 AM
Basement - need to bust up about 1 ft deeper FallenAngel Building & Construction 7 08-15-2007 09:09 AM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.