I’m in the process of building an addition to my 1906 shingle style Victorian. Over the past 24 hrs we had a strong wind driven (~40-60 MPH) rain storm. The sheathing is plywood on the new parts of the building and 1×10 rough sawn lumber on the older parts of the building. I notices there are a number of moist areas on the old sheathing where the nails come through. There are no leaks around windows and no evidence of water coming from above (roof, gutters, etc). the only spots were in the first floor of a flat (2 story section of wall). The second floor is sheathing in a combination of rough boards and 3/4″ sheets of Advantech subfloor (since it was the proper thickness). All roofing, ice&water, gutters, etc are new also.
The exterior of the house is covered in red cedar shingles (preprimed & painted) with a 5″ exposure to the weather. Before shingling we covered the sheathing with 6′ rolls of Tyvek making sure to overlap the seams my about 3″. We did not tape the horizontal seams since nailing the shingles creates thousands of holes (so what is the point) and to allow for any moisture to escape “if it ever” got behind the siding. The job is tight and neat as a pin!
I’m completely baffled as to how the water is getting in, but more importantly what should I do (if anything) about it before I insulate? We plan to use icynene (spray foam) for the wall insulation.
Is a little moisture behind shingle siding normal? We did not use any breather under the shingles since the siding would not align with the existing building. We also had a number of shingle details (flairs, curves eyebrows, etc) that could not be done properly if we put anything under it. Should I put some of the cedar breather material behind (interior) the sheathing before I insulate? Since Icynene seals so well should I just ignore it and assume that the moisture will work its way out before any mold / rot could happen?
Any advise welcome
Bruce
Replies
Are you sure you're not seeing condensation?
I would ask the same question as Dan. If you introduce say a propane space heater (moisture producer) or even kerosene for that matter into unfinished new construction/remodel, have minimum air movement and high int. humidity/cold outside air temp there will probably be condensation on the cooler surfaces-quicker on metal (nails) but also on sheeting. Usually not on the framing because of it's mass.
If there's no heat in the addition, then maybe something in the shingling or flashing is amiss.
A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
funny you should suggest this.. I was just thinking that same thing! There is no auxiliary heat in the space, but I do leave the door open from the basement. The waste heat from my gas boiler will warm the space by a couple of degrees. It was unusually cold (20-30) for a couple of days and then warmed up a bit to 40's and then rain for about 20 hrs straight. The only problem with the "condensation theory" is that there is no moisture on any other wall of the addition, or other area of the same wall that was sheathed with plywood. The wall in question faces south / east, the direction of the rain/storm. The upper half (2nd floor) of the wall is protected by a overhang and sheathed in advantech with no sign of moisture. It's still a puzzle..
I hope you would find the source, I wouldn't cover up b/4 I did.
How bout this. Cover the inside of the whole wall in question with visqueen. Assume the same temp difference and maybe wind direction (our prevailing is from the SW). Does water condense on the room side of the visqueen (I'm sure it will on the otherside if it is still damp. But on the room side might indicate airborne condensation.
Boiler operating properly? Moisture from a burning boiler would suggest a problem with the venting of CO from that appliance.
Moisture from the basement which the boiler is in would be not wanted but "normal" and not a hazard to life.
This sluething is no picnic is it? The partial and localized nature of it does nothing to help till you eliminate some common "no problem" sources.
best of luck.A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Do you have any pictures you can post of the ext.? Interior too I guess wouldn't hurt.
You say some is boarded up, some ply/advantech? Why the combo. Was there a problem with some sheeting b/4?A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Sounds like you live near me. We had 70-75MPH winds the other night. SE blow. It was the worst I have seen since living here - and steady all night, not just a few high spots.
Today, I checked out a partly finished repair and found spots where water had blown uphill nearly three inches.
Tyvek does allow some permeability to allow for moisture to escape an assembly.Icynene tho is tight for air flow, but will wick and absorb water.
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From the first post: "I noticed there are a number of moist areas on the old sheathing where the nails come through."
I couldn't help but think of a time before the cottage we use weekends got reroofed with ridge vent added. Too much moisture was getting into the attic space (poorly built structure, not intended for winter use). What I'd see in cold weather was frost on the nails penetrating the roof deck boards, but wetness (not frost) on the underside of the decking itself. I'm sure condensation was occurring on the nails before it got cold enough for frost to show, but the frost made quite a visual difference.
What I am wondering is if in your case the nails through the old sheathing are larger than those in newer sheathing, or if the new ones don't penetrate the sheathing at all. The larger nails penetrating the sheathing will be locally colder spots, since the metal is conducting heat more readily to the outside than the wood does. If you have a marginal humidity problem, the nail surfaces might conceivably be mini-dehumidifiers for the air local to the sheathing, with the wetness migrating to the wood around the nails and showing up as wet spots.
With a lot more humidity, the nail surface wouldn't be enough to do the job, condensation would occur on the wood also, and the rate would be fast enough to show up as surface wetness and not just be absorbed into the wood without showing.
Just another stab at what could be occurring. Fortunately, if this is the problem, then finishing out the wall with insulation and vapor retarder will make it go away.
Edited 11/26/2008 4:29 pm ET by DickRussell
Here is a link to photos of the project http://picasaweb.google.com/btrvalik/Renovation08. The area of sheathing is between the 2 rightmost windows on the first floor on picture #28. I posted some new picture showing the sheathing. It a bit hard to tell but the wet areas are the reddish (approx 4" w x 1" H ) patches in the middle of a couple of boards. Photo #39 shows the mix of old and new framing / sheathing. We tend to only demo what we have to here in New England.. lot's of nice old timber that are still straight as an arrow. When we demoed, we found that my sill was level +/- 1/16" over 18 ft.. and this is on a rubble stone foundation! I will be nowhere near that straight with I'm 100+ ;)
Bruce, where on this picture is the area of possible water intrusion?
edit: I don't know what happened. I'll wait to see how you see this picture, me? I see it plastered over your first post. Yikes.
I'll delete my post if that's how you see it.
A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Edited 11/26/2008 6:49 pm ET by calvin
Edited 11/26/2008 8:06 pm ET by calvin
bruce... i went to your picassa site ..... nice looking work..
couple things..
i don't trust tyvek
some of the areas that you suspect of leaking''' i'd strip and see what the evidence shows
espcially suspect are things like tyvek corners... tyvek splines (around windows )
we do a lot of remodeling of houses built in the '80's with cedar and tyvek... they all show lot's of evidence of leaking
we used tyvek once... about 15 years ago...went back to felt...15 lb & 30 lbMike Hussein Smith Rhode Island : Design / Build / Repair / Restore
bruce....
all i can see is your picture it covers up the left side of your text
Mike, must be sunspots. I tried to copy his pic and posted in my last message...............
Somehow, boom it goes to the front of the whole thread and smacks itself right on down on it.
I'll give deleting my post a try and hope for the best.
God only knows moderation won't be around to lend a hand on this faux paw.
Sorry.A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Well, I ''cut'' the picture. That worked.
Dare I try to post it again?A Great Place for Information, Comraderie, and a Sucker Punch.
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
nice looking project
in my somewhat limited experience with wood shingles, they can pass a lot of water through them in driving wind/rain conditions.
we recently replaced a section on a pretty well exposed area of a church for mostly cosmetic reasons. about 90-95% were in good shape, but they were installed without any felt or anything else. these were origonal to the building (I think) about 70 yrs old. they were over rough sawn full 1" x6" sheathing, which was in good shape despite having MANY water stains. I think the sheathing didnt deteriorate because it was open attic behind and could dry out. In your case though you might trap water in there with the foam & tyvec.
Sorry, but I agree with mike smith, I would want some felt under those shingles at the least.
But won't water just blow through the nail holes in the felt?
The mark of the immature man is that he wants to die nobly for a cause, while the mark of a mature man is that he wants to live humbly for one. --Wilhelm Stekel
Maybe, as I said I am no expert on shingles, but the felt is a better barrier and can absorb a little moisture I think
Thanks for all the advise.. Stripping is not really an option.. what do you strip? The entire job? We get weather on all sides and just because the water "showed up" in the rough sawn boards, it does not give me comfort where we used plywood. Plywood may trap more moisture than the rough sawn since it does not "wick" the way the old boards do.This addition was built based on everything we understood to be best practices. The master carpenter on the job has over 30 yrs of experience framing and trimming old houses. Plus, we are all avid readers of FHB so that naturally makes us smarter than the average wood pecker! We took extra care on each step. All inside corners /intersections were step flashed and outside corners were glued with Gorilla glue. Windows were properly flashed, Shingle joints were properly woven and stepped. Zoom in on some of the details and You'll see some of it. The windows were all cased in Honduran mahogany and Spanish Cedar to avoid using any form of pine on the exterior. Factory pine casing from top manufactures last about 10 yrs around here. The jams and sash are from Marvin. The casing / windows were built with pocket screws and glue, every joint /seam was caulked, etc. All shingles are pre-primed red Cedar topped with 1 coat oil prime and 2 coats latex. Text book stuff. Other than using engineered lumber (lot of it!), and a little bit of Aztek trim, we constructed the addition using much the same logic as the builders of the original house. The original frame was all mortise and tenon joined.. we used steal plates and bolts. They had old growth for the timbers, we have layer upon layer of glue for timbers.The real beauty of a "Shingle Style" house is that every element is in fact put there for the purpose of shedding water. The "shirts" at each story or the eyebrow above the window are there to kick water away from the house. Every intersection is trimmed out with a piece of molding..for both beauty and weather. There is a good reason why these houses were built all over New England for the last hundred years.. we call it a Noreater.One of the earlier posts hit on a key point. All the rough sawn boards clearly show signs of past water staining. In 1906 the stud bays were wide open. Air was able to come in under the foundation skirt and exit via the beadboard overhangs. The sheathing was all open decked (rough sawn boards with air space). The house likely had a wood roof, and it still has wood gutters. They did not paint shingles back then, they "treated" them with boiled linseed oil and turpentine. I still use this same concoction on my fir gutters. I believe most of the trim and some of the siding date back to the original construction. The weather side of the building has clearly been re-shingled numerous times, which is typical around here. Over the last ~30-50 yrs the house has been insulated with blown-in and/or fiber glass insulation. The shingles that originally covered this wall were warn but not horrible. We stripped it back to the corner when we re-sided. The original frame / sheathing showed some signs of water staining but no sign of rot and was remarkably straight and true.Perhaps this is just the reality of wood shingle siding in New England? The real question is what if anything should I do before insulation? Since this is such a small amount of moisture, maybe if I just allow the boards "breath among themselves" by providing a minimal airspace I'll be O.K. I was thinking I could apply a layer of cedar breather to the back of the sheathing and then cover that with tyvek. The tyvek would mainly serve as a way to keep the foam out of the breather.Edited 11/27/2008 10:17 am ET by btrvalik
Edited 11/27/2008 10:19 am ET by btrvalik
i've done allot of cedar shingle w/ the timberpeg comp. i work for in the north east. i can give the advise that was past to me about your question. We now have to put homeslicker behind our shingled walls due to sheathing rotting out. I can explain alittle better, in the "old days" there wasn't insulation and when they did introduced it, it still allowed air movement. with our new technoligy of open and closed cell spray polys are fanomanal, but you have to be careful with them they will reveal a whole new set of problems if you not carefull. perfection shingles aren't compleatly water proof and will allow some measuremanet of moisture threw them. to the under side of them. U might find down the road shingles severly cupping compared to the origonal house. that is what i know what you can use from it i dont know, by the way great work!!
Thanks for all the input. This discussion also motivated me to organize my picasa site.The overall project can be seen at http://picasaweb.google.com/btrvalik/Renovation08 and the water issue can be seen at http://picasaweb.google.com/btrvalik/DampSheathingPhotos
bruce....where is this site ?i looked at your picassa set of the leaks... that's what they are... leaks..
this is not a condensation problem... those are leaksMike Hussein Smith Rhode Island : Design / Build / Repair / Restore
The house is located in the Boston area.. and leaks were a result of Tuesday's rainstorm which I believe you also had the pleasure of experiencing down in R.I.
yes, one of my customers brought me up in his attic to look at a chimney leak that we rebuilt and reflashed two years agoMike Hussein Smith Rhode Island : Design / Build / Repair / Restore
I have been looking at some of the photos. I am on dial-up and this is slow.Can you help orient me to hwere this is on the outside? I see you have a fan running at a wall near a curved shingled corble support for the cantilever. I also agree with mike - this looks like a real leak, not condensation and probably not multiple penetrations from nails on the whole wall. This looks more specific.There do appear to be a couple details lacking that I've seen so far. For instance, no Tyvek on the curved corbel and possibley no flashing tape at the inside corner there.
There is a lack of flashing tape or tarpaper at three sides of all the windows I have seen and the Tyvek at window tops is done in the old X-0cut fashion. I haven't seen it all yet, but don't see any signes of flashing at head casing of windows tucking under the tyvek.
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It is a beautiful job.
I think I located the exterior of where the leak is. if these photos are current, you have no soffit material covering the bottoms of the joists at the cantilevers yet. That is the main suspect location for wind to have blown water in, IMO
http://picasaweb.google.com/btrvalik/Renovation08#5273072787576995746
Also where the trim there comes back to the shingles, is there a metal slip flashing to lead water onto top of shingle courses to kick water out?
I presume you are waiting to soffit this until after the insulators blow?
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Blowing in via the soffit is an interesting idea. Yes, as you suspect the soffit will be closed with beadboard once we insulate that area. the area of the wall that was effected was about 2 ft to the right of the cantilever; 1ft above the windows, extended all the way (in spots) to the corner. I could certainly envision a scenario where rain would blow under the soffit, hit the sheathing and then run horizontally along the rough sawn boards. This really is the only area that was not protected.All corners were step flashed and weaved. The molding was applied after the under course, chalked, the top shingle was then coped and pressed into the chalk. The building was wrapped with tyvek prior to installing the corbel. Since the corbel was self contained and was not directly open to the interior of the building, we saw no need to tyvek it. We did not want to have to deal with crumpled up tyvek / tape given all the weaves and angles. I've never built this kind of detail before, so I also wanted to be able to glue down a shingle if it was required.. turns out we did not need to.
I could only be more certain if I were right there on site, but I believe we know where the water got in then, and that it is unlikely after you close in the soffit there.That was a wicked bad storm!
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Once again thanks for everyone's help. We had another good storm on Sunday.. but it fell down instead of going sideways. The good news it that the sheathing stayed 100 % dry. At this point, I'm fairly certain that it came in via the soffit. Water was able to blow in, hit the tyvek and then roll down behind the shingles. It was a little confusing since the water stains started about 2 ft away from the soffit, but we all know how tricky water can be. It really was the only logical explanation.. one that escaped me!Note that the photo of the fan above has nothing to do with this issue. This was a photo from late this fall on a day I painted a little too late into the evening. "I was able to paint this late last month" Who needs daylight when you have a fan and a halogen light :)Bruce