Vinyl Siding - Weather Resistive Barrier

[PSUengineer1]

Section R703 of the 2012 International Residential Code (IRC) requires a weather-resistant barrier (also commonly referred to as a water-resistant barrier) behind exterior veneers, including vinyl siding. The weather-resistive barrier allows any water intrusion behind the siding to run down the wall without damaging the sheathing behind it.

The attached pictures show a situation where moisture is entering the house near the windows. Peeling back vinyl siding shows scarce application of weather-resistive barrier over insulation. Does the insulation qualify as a weather-resistive barrier? Do you think the water is coming from the lack of weather-resistive barrier?

Please note no flashing angle from back of vinyl siding at pitched brick sill. Pitched brick sill is only sloped about 4 degrees and has a J-channel at top of brick sill that is pooling water (see pics attached).

Looking for comments, thank you.

 

[CELinOttawa]

I don't know enough about vapour and moisture barriers (other than that they are different things) to be of help with your actual question...

BUT, in your last photo it looks like the courses of brick go all the way down to the soil. That's a no-no. Also, where are the weep holes?

Water will ALWAYS get through brick... Without weep holes it has nowhere to go. After that a microclimat forms in behind the brick in the air gap and all hell breaks loose. I'd say that's contributing to this problem.

Remember: In building science work you're looking to prevent a problem, in building forensics you must resist the temptation to think that there is *a* cause. It is nearly always a confluence of factors. Good luck, and keep us all informed!

 

[JWAII]

I'm guessing that the window isn't properly flashed and the lack of WRB doesn't help. Section R612.1 of the IRC talks about requirements for window installation (and flashings as you mention). Agree with CELinOttawa in that water/moisture will ALWAYS get behind claddings. Managing the water within the cavity and behind claddings (allowing it to drain and evacuate) is key. I'm also guessing that water may be getting into the wall cavity at the window head?

I suppose (I would need to be convinced) that an insulation could act as WRB, but that sounds like a bad idea from the start.

I've seen new construction windows with WRB and flashing products "installed" but poorly integrated. You guessed it - water damage. The devil is in the details...

 

[Ron]

You need to do further investigation. Yes, it's clear that the water-resistive barrier is not installed properly and it is also likely that the window was not flashed properly; however, you have not isolated that the window frame leaks or does not leak at the sill-to-jamb connection. This is common, but becomes an argument between the installer and the manufacturer of the window.

What you have uncovered is a bit more complicated than it would seem from a forensic standpoint. Here's why....

1. Is this a single family residence of part of a condominium. Check this as the residential code does not apply to condominiums....the main building code does as condominium construction is considered commercial construction, not residential construction.
2. Insulation is not a water resistive barrier and should not be considered so. There's not a clear picture of your sheathing behind the vinyl siding, but are you sure you have rated sheathing? (structural rating...not a waterproofing issue other than non-rated sheathing allows more structural movement, thus more impact on the waterproofing at interfaces).
3. The water-resistive barrier has to be tied into the window flashing and all flashings have to be installed "weatherboard" fashion (meaning they are installed from the bottom, up and shingled as you would a roof).
4. Contractors divvy up the work to subcontractors without adequate consideration to coordination or sequencing the construction in a proper manner. Find out who was responsible for each task and then you'll likely see who screwed up.
5. Look at the design details. They are usually miserable for waterproofing and flashing.
6. You are correct. There is no "thru-wall flashing" at the top of the brick rowlock course. This is required by code (see Chapter 14 where there is a requirement for flashing to direct water that penetrates the facade to be directed outside the wall substrate or cavity).

Keep us posted on the progress. Check your state's statute of repose and statute of limitations for all involved.

 

[Compositepro]

The window flashing may be inadequate but the most serious problem appears to be the bottom trim piece on the vinyl siding. It is catching water running down the outside wall and channeling to the window where you see the water damage.

 

[dhengr]

Jimjxs263:
Wow! That’s worth a whole book on how not to do things; with each picture being a new chapter. Although, that doesn’t look like outlandish construction for a 20 or 30 year old house, but it certainly indicates a lack of knowledge about how the various details work. We didn’t know enough, didn’t do enough or didn’t pay the same attention to water penetration details then, as we do now. Buildings dried better when they weren’t so tight, so they fooled us into thinking we were o.k. While you can’t expect that bldg. to meet today’s IRC or IBC, it will eventually need significant repair, and siding replacement, window or brick veneer replacement, and at that time I certainly would install a water barrier system, with all appropriate flashings, etc. In the mean time, something should be done to keep from dumping water from the vinyl siding into the window corner. The existing vinyl and brick details will make this difficult, each condition will require its own detail design. And, I would also investigate (open from the inside) the wall under and around each of the wet spots, and I’ll bet you’ll find water damage in the wall.

Photos 1, 2 & 3.... Vinyl siding almost always leaks in various places. It usually sweats on the back side, thus the bottom drain holes on each piece. This leads to a fairly moist space behind the vinyl. The stapes look to be a little over driven on the vinyl piece in photo #2. What is and why, the silver tape and the single pieces of 15# felt. That exposed sheathing looks like Celotex, Bilt-Rite or some such, and there may be no plywood sheathing behind it. It actually looks surprisingly dry.

Photo 4, with the A/C.... The J channel at the jamb of the window (end of vinyl) and at the base of the vinyl (top of brick) will funnel water right into the window jamb right above the sill. The top of the brick should slope more, so it drains quicker and better. That detail is notoriously difficult to do right and to maintain. It sucks water, freezes and thaws and goes to hell. There should be a separate flashing on top of the brick, under the J channel, and behind the water barrier. This flashing should have a dam built into it at the window jamb and behind that J channel, and this should be worked into the window flashing, and behind the water barrier. Almost like a kick-out flashing. I don’t particularly like this condition, but the J channel at the top of the brick should probably have .25" holes drilled in its face surface, so it drains regularly (distributes the water) onto the brick. Show an elevation photo of this window corner. That’s going to be a difficult detail to flash and dry-in.

Photo 5.... Shows exactly where the water is getting into the wall, at the window corners. You have to flash and dam that corner to direct the water outward. Again, almost like a kick-out flashing. But, until you have a proper water barrier and can flash the window into the water barrier this will be tough to do. And, the brick veneer staying in place will complicate this further. It has no weather barrier system behind it either, I assume. How much air space btwn. the back of the brick and the sheathing we see? What brick ties?

Photo 7.... As ugly as it will look, the corner flashing, kick-out flashing, at the window corner, should literally be a little scupper which dumps the water out beyond the face of the brick. Then the same scupper at a .25" drilled hole in the J channel, at intervals in long runs. You might caulk window heads and jambs, but don’t caulk the bot. horiz. joint, you want it to drain.

 

[PSUengineer1]

Wow! Thank you everyone for the helpful replies.

I will share with the group what I come up with, once I sit down and review

@dhengr: a piece of insulation is broken off in attached pic. Would you call this celotex? Was wall sheathing typically installed behind celotex? Any others, please chime in too.

Thank you again.

 

[Ron]

jimjxs263....how did you do the water testing? Was it done in accordance with accepted standards? Is there an attorney involved with this? In what part of the country is the building located? Agree with dhengr...you need to do more destructive observation. Time to tear up a few things and see what's there.

 

[a2mfk]

APA has some good references to proper moisture barrier and flashing construction:

http://www.buildabetterhome.org/bbh_walls.cfm

Do you guys like the bottom brick sill detail for this specific situation? I think this was Ron's #6 comment.

Cross-section of window in brick veneer over wood wall

Prior to doing demo, a moisture meter may give you an idea of where the water is getting into the wall, though there may be multiple intrusion points. Go around the sill, jambs and header and see of there is not a significant difference in moisture content. Your photos of water staining and fungal growth point towards the sill and bottom of the jambs, but I suppose that does not eliminate the possibility of intrusion from the top or sides of the window that is draining down and collecting at the sill.

The water stain on the brick in the last picture- is their a sprinkler head nearby? Or is this from water draining from around the left side of the jamb.