Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

rotten studs

rotten studs

rotten studs

I'm working on a building that's got some water intrusion problems.  So far it's only a little plywood at the corners but I've got to go check out a section where the studs are rotten.  I'm guessing that I'm going to find the vapor barrier is on the inside of the studs.  The building is in a hot, humid area & pretty sure this is what is causing the rot in this area.  We never apply vapor barriers inside anymore.

We're going to replace the studs, plates, sheathing, etc. only in the affected area.  ($$ is tight).  Would it be best to have no vapor barrier at all or add tyvek to this small section that's being uncovered?  Obviously it would be best to fix this everywhere but that's not currently an option.

RE: rotten studs

Venting the area would help.

Mike McCann
MMC Engineering
Motto:  KISS
Motivation:  Don't ask

RE: rotten studs

agree with mike,
hope this isn't a fix-it job to flog off to some poor sob.  

Arguing with an engineer is like wrestling with a pig in mud. After a while you realize that they like it

RE: rotten studs

If you eliminate the Tyvek, make sure you still comply with Code requirements for weather-resistant exterior wall barriers.  What is the exterior finish?  What state are you in?


RE: rotten studs

Yes...need to know the exterior finish and where you are.  Not likely that there is a vapor barrier on the inside causing this...that's a relatively rare occurrence/mistake in hot, humid areas.  More likely the exterior flashing/water resistant barrier is not done correctly.  Check under a few windows and see what you find.

RE: rotten studs

Also, as Scottiesei noted, you likely have a building code requirement for both air infiltration and water resistive barriers.  Since you mention plywood (is it plywood or OSB?), then you likely have a veneer system such as stucco or stone.  Both can be problematic from a water intrusion standpoint.

If you are finding damage at the corners, you likely have more significant damage at large penetration areas such as windows, at detail bands,and at any unflashed/unsealed penetration such as phone/electrical boxes, hose bibbs, etc.

Post a few photos of the exterior features.  

RE: rotten studs

Checked out the building today.  It's in Emerald Isle, NC.  There is plastic between the studs & drywall.

Eliminating Tyvek will not be an option as code will require it.  

Exterior is cedar siding (being replaced as needed with Hardi) over tar paper, 5/8 gyp board, plywood, studs...

RE: rotten studs

Main question is to leave plastic inside or remove?  I think this is a big part of the problem.

RE: rotten studs

Unless the plastic on the inside is creating a mold issue on the inside surface (back of drywall), I wouldn't worry about it.  That is usually the issue with the vapor barrier on the inside...it doesn't usually affect the exterior sheathing, one way or another.

Check flashings on the exterior  With rot at the corners and the fact that you're using cedar siding, it is likely that the corner trim was not installed correctly or the siding was not terminated properly at the trim.  Don't let them make the same mistake with the Hardi-board.

Make sure the flashings are done properly around the window and that the sill flashing in particular weeps to the outside of the siding.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close