What Causes This To Happen ?

easy sider

If this is thermal bridging, why is it only happening to the end walls ? Maybe I should go back to the building and unlock a pannel off the front or back to see if the wall is constructed differently than the ends.

Paulie

Yeah why not? Look behind the panel. I putting my bet on thermal bridging because it follows the studs. How else can you explain it?

By the way are there bathrooms against the end walls? I see what looks like fart fan exhausts in the one picture.

loneframer

If they aren't fire rated, they probably are done differently. I've done alot of this type of construction, fire rated sides, conventional plywood construction front and rear. Just a thought, are the walls stained within 4' of the corner? There could be a fire rated plywood shear panel on the corners, but not necessarily.

easy sider

We feel that this is thermal bridging. What can be done to eliminate this problem. Would 1/4 fan fold underlayment be enough to keep this area warm enough ? Is there a product that is thin enough to slip under the outside corners that would stop the thermal bridging ?

Thanks
Bill

loneframer

I think the culprit is the siding being stud nailed because of the fire rock. the stud is the path of least resistance, even with fanfold the nail continues to be the conductor. It may be worth a shot but I wouldn't wager on it. Most siders don't bother stud nailing with traditional sheathing, although I do because of the coastal storms in this area.

Paulie

I had a job somewhat similar. No firerock, standard residential construction but had pipes freezing on outside wall and didn't want to tear off corners. I used 3/8's fan fold with mylar. I didn't think it would help just being 3/8's. I just checked on it this last november and they said they never had a problem since.

I understand what loneframer is saying about the nailing (and I agree) but what else can you do?

thesidingpro

You have to stud nail no matter what type of sheathing. Plain and simple.

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loneframer

I agree, I'm just saying many "pros" don't, and many builders don't know any better. I see it over and over again. As well as poor flashing and papering details. Water management should be job one for a siding co. and rarely is, or in my experience, never is.

thesidingpro

pro's don't hacks do. Huge difference.

And I agree. I see it blowing off all the time and most cases a catching the studs was all would have been needed.

There was a crew around here that stapled everything without worrying about studs at all. It's flying off everywhere.

I know because I lost a bunch of work to this outfit several years ago based on price.

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loneframer

It jerks my gherkin that these guys are making money hand over fist while producing sub-standard product. No pride and no passion, just a paycheck.

rojigga

Not only that who likes to nail into sheathing without a stud behind it? Way harder when theres no support behind it. Damn sheathing's to bouncy in between studs!

loneframer

Yes, but for many, close to stud will suffice.

rojigga

True enough loneframer, true enough.

easy sider

Ok. I looked under the front and back wall and it is sheeted with plywood. No problem on these walls. I sent pictures to Alan Hoying, R&D at Ply Gem, formerly Alcoa, and am waiting for his departments collective thoughts.

Thanks for all the educated guesses.
Bill

Bill Z

Just curious about roofing nails with aluminum siding. When I started in the siding business, everything was aluminum siding and we ALWAYS used aluminum nails because of the reaction between galvanized products and aluminum. It wasn't until vinyl became popular that we used roofing nails for siding.

Any possibility of a reaction between the aluminum and the galvanized?

loneframer

I think you may have something there. I missed the fact that it was Aluminum siding, electrolosis could very well be the culprit, only thing that baffles me now is why end walls don't have the same problem. Hmmmmmm, why then would it not only show at the nailing hem coarse. Hmmmmmm

Bill Z

Maybe the heat and/or moisture from the dryer vents, assuming there's a slight breeze from the right of the picture, speeds the process? Or perhaps the proximity to the electric meter does it?

easy sider

This is ALCOA SUPER V D-4. The v stands for vinyl. This was the early generation of Alcoa vinyl siding before Alcoa aquired Mastic. Alcoa stoped production of Super V around 1990-91.

VSI states e.g. roofing nails are a suitable fastener for vinyl siding.

Thanks siders
Bill

Bill Z

Aah, shows how long ago I messed with siding. Just automatically matched Alcoa to aluminum. My bad, blows my theory,,,,, since it's vinyl, I go with the static electricity theory. Many years ago, when selling aluminum, we rubbed the vinyl and created static to show how vinyl would attract dirt. Maybe that's actually happening now....

loneframer

Shnap man, I go and jump on the electrolosis wagon and the damn wheels fall off. Back to the thermal bridge theory for me.