Condensation Inside Wall On Vapour Barrier - Building & Construction - DIY Chatroom Home Improvement Forum

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


Thread Tools Search this Thread
Display Modes
Old 05-14-2010, 03:42 PM   #1
Join Date: Feb 2009
Location: British Columbia, Canada
Posts: 68
Rewards Points: 75

Condensation inside wall on vapour barrier

I am in the middle of re-insulating my outside wood frame walls. I got a bit done the other day and noticed when I came back to it the next day, there was condensation on the vapour barrier inside the wall where the insulation is? The following day it was gone??? Is it because the whole wall isn't finished yet? Or is it a normal cycle for some moisture to condense and dry back out in the wall.
Its wood frame, with OSB sheathing, building paper and cedar siding. Fibreglass insulation with 6mil poly inside. Test area was a south facing wall and it has been sunny and warm during the day. I want to sort this out before I finish the whole thing off.
rovers1973 is offline   Reply With Quote
Sponsored Links
Old 05-14-2010, 10:00 PM   #2
Totally screwed together
Join Date: Dec 2006
Location: Cypress, SoCal
Posts: 325
Rewards Points: 250

So you are seeing water from the inside of the wall, contained within the insulated cavity through the clear plastic, right?

Congrats, you are seeing thermally driven vapor. Normal water vapor gets into the surface of the structure, then it gets heated up by the sun. This actually drives the vapor deeper into the structure. What should not be happening is actual condensation on the inside of the plastic. There should be enough insulation so that any vapor is gently warmed before it hits a condensing surface... where it will drip down, collect, cause rot and mold and attract termites.

You've got your walls open, might be time to thing about GOOD insulation. Fiberglass batts is not under that heading.
xxPaulCPxx is offline   Reply With Quote
Sponsored Links

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
vapour barrier on ceiling of bathroom? wilsonfrench Building & Construction 20 01-29-2012 08:08 PM
Densshield and Vapour Barrier rayf01 Building & Construction 6 01-01-2010 12:55 PM
Installing insulation and vapor barrier to exterior basement walls Fernando Sinn Building & Construction 11 04-11-2008 11:11 AM
How important is plastic vapor barrier on foundation wall? slatergrl Remodeling 5 02-18-2008 12:49 PM
Minimum Clearance to Vent Inside Wall? MikeinBurien Plumbing 12 12-05-2005 11:03 PM

Top of Page | View New Posts