Jump to content

Found no home wrap behind siding


Recommended Posts

Today I had to remove an exterior window from my home. We had recently installed a wood burning stove and the window needed to be removed. Upon removing the cement board siding I found no house wrap of any kind. My home was built in 2005, and I was surprised to find this out. Is home wrap required? If not would it be in my best interest to remove all siding and add it now? I have been looking for ways to improve the efficiency of my home. Would this help much?

Thanks,

Matt

Link to post
Share on other sites

House wrap is about retarding the propagation of moisture through the wall, not so much about energy efficiency.

I don't know if a vapor retarder was required in GA 6 yrs ago. At the minimum, it makes good sense to do so when you build the house or replace the siding.

When you removed the siding did you see any evidence of water intrusion? Any visible evidence of water intrusion from inside the house, anywhere, any room?

What building material is installed immediately behind the fiber cement?

Was there any flashing installed on the window opening?

Marc

Link to post
Share on other sites

Wrap isn't the best choice of material in a humid climate because it tends to trap water instead of allowing it to dry out. Lots of builders have returned to using building paper behind FC siding around here.

Did they use anything as a WRB behind that siding?

ONE TEAM - ONE FIGHT!!!

Mike

Link to post
Share on other sites

Wrap isn't the best choice of material in a humid climate because it tends to trap water instead of allowing it to dry out. Lots of builders have returned to using building paper behind FC siding around here.

Did they use anything as a WRB behind that siding?

ONE TEAM - ONE FIGHT!!!

Mike

At least one commonly used wrap, Dupont's Homewrap Tyvek, has a perm (56) which is comparable to building paper.

Marc

Link to post
Share on other sites

Hi Marc,

It's not a question of perm rating; they all diffuse water vapor - it's a question of trapping water. Remember that thousands of nails get driven through the product. With building paper, when water works in around those nails and the paper eventually gets saturated it provided almost no protection against moisture. When the rain quits, the paper dries in two directions - into the home and out through the cladding. With ordinary flat plane wrap that can't happen and water ends up trapped between the face of the wrap and the sheathing. With an older house with T & G sheathing and wrap applied, that's not so bad; with a new house with plywood or OSB that trapped water can cause substantial rot - especially with OSB.

Spend some time over on my Building Science Forum at JLCOnline and check out the archived discussions about wraps and you'll find that a lot of guys who'd changed from building paper to wrap ended up going back to building paper. It's this issue with wrap that's motivated at least one company to create a wrap that has tiny raised ribs that allow the wall to drain.

ONE TEAM - ONE FIGHT!!!

Mike

Link to post
Share on other sites

Today I had to remove an exterior window from my home. We had recently installed a wood burning stove and the window needed to be removed. Upon removing the cement board siding I found no house wrap of any kind. My home was built in 2005, and I was surprised to find this out. Is home wrap required? If not would it be in my best interest to remove all siding and add it now? I have been looking for ways to improve the efficiency of my home. Would this help much?

Thanks,

Matt

Before the 2006 International Residential Code, no weather-resistive membrane was required behind most exterior wall covering (siding) materials.

If one is not there, and you otherwise have no water infiltration problems, don't worry about it...

Link to post
Share on other sites

House wrap is about retarding the propagation of moisture through the wall, not so much about energy efficiency.

I don't know if a vapor retarder was required in GA 6 yrs ago. At the minimum, it makes good sense to do so when you build the house or replace the siding.

When you removed the siding did you see any evidence of water intrusion? Any visible evidence of water intrusion from inside the house, anywhere, any room?

What building material is installed immediately behind the fiber cement?

Was there any flashing installed on the window opening?

Marc

I did not see any water issues other than the back door i replaced due to water problems, but that was a different problem. behind the hardiplank is osb board. I dont see any flashing around the windows, but they are new construction windows and I did not see any water problems around the one I removed. I also have not had any moisture problems in the home (other than the crappy windows I will be replacing). So if I have no moisture problems, it would not be beneficial to wrap now?

Again thank you so much for the advice,

Matt

Link to post
Share on other sites

This reminds me of a visit to a nephew in Atlanta several years ago when he asked me to come over and tell him what I thought of his new house. There was no underlayment installed under the shingles. From the sidewalk across the street, I could see the new OSB roof decking where the cornice had sagged a little. Not just his house but many others up and down the street. The entire subdivision was new. Such were the codes of GA.

I'd suggest that you assume that a weather resistant barrier (WRB) of some type along with repairs to water damaged areas will be needed at some point in the future, and that you budget for it. If you're inclined to do it now, it would save you some additional expense later.

Marc

Link to post
Share on other sites

I did not see any water issues other than the back door i replaced due to water problems, but that was a different problem. behind the hardiplank is osb board. I dont see any flashing around the windows, but they are new construction windows and I did not see any water problems around the one I removed. I also have not had any moisture problems in the home (other than the crappy windows I will be replacing). So if I have no moisture problems, it would not be beneficial to wrap now?

Again thank you so much for the advice,

Matt

So, new constructionj windows need to be flashed; that's a given - and James Hardie wants to see head flashings above them with a quarter inch drainage gap above those head flashings as well as over all other wall penetrations larger than an inch and a half. They also want to see splines (flashings) at every butt joint. They do say that WRB is to be installed in accordance with local building codes; so, if it wasn't required under local codes I suppose the installer was off the hook with the local code bubba but won't be off the hook with you if/when that OSB begins to rot.

Click here for a copy of the J.H. best practices guide for your region (Wait for it, it's 26 pages and over 16 Mb). The best practices guide is supposed to be used by the installer in conjunction with the installation instructions; but most of the installers I've met personally haven't ever seen it.

ONE TEAM - ONE FIGHT!!!

Mike

Link to post
Share on other sites

Maybe Hardie Plank is different.

From the Vinyl Siding Institute (trade organization of the vinyl siding manufacturers)

http://www.vinylsiding.org/publications ... Manual.pdf

Water-Resistive Barrier

Vinyl siding has always been designed as an exterior cladding, not a water-resistive barrier.

Vinyl siding is designed to allow the material underneath it to breathe; therefore, it is not a

watertight covering. Because of its design and application, it provides a supplemental rain screen

that enhances the water-resistive barrier system by reducing the amount of water that reaches the

underlying water-resistive barrier.

What Is a Water-Resistive Barrier System?

It is a system that includes water shedding materials

and water diversion materials. Water-resistive barrier systems commonly consist of a combination

of exterior cladding, flashed wall openings and penetrations, water-resistive barrier material, and

sheathing. Effective water-resistive barrier systems will shed the water initially, control moisture flow

by capillary and diffusion action, and minimize absorption into the wall structure. The level of water

resistance required is determined by the applicable building code and structure.

Best Practice:

To achieve designed performance, vinyl siding must be installed over a water-resistive

barrier system that includes

1) a continuous water-resistive material and

2) properly integrated flashing around all penetrations and where vinyl siding interfaces with other building products such as brick, stone, or stucco.

Refer to the manufacturer?s instructions for specific product applications and recommendations.

Whichever product(s) you decide to use as part of a water-resistive barrier system, be

certain the materials meet the applicable building code by contacting the manufacturer of the waterresistive

barrier material(s). Always consult the applicable building code for minimum water-resistive

barrier requirements in your area. Keep in mind that additional measures may provide better protection

against water intrusion than the minimum requirements of the building code.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...