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I’m not sure if I have a problem or not, but I figured there was no better bunch to ask than you guys. But here is the problem I am about to have:
Over the past several winters, I have noticed that when the temperature outside gets chilly enough, when one looks at the side of my house, you can see the outlines of the studs inside the walls. The siding is frosty/ dew covered everywhere except for where the studs are within the walls. The house was built in ’87, traditionally framed (platform), 2X4 walls, OSB sheathing, and (shudder) vinyl siding. FG batts in exterior walls. Not sure if any housewrap of the like was used. I figure, most likely, there is Tyvek or something similar under there.
This problem only occurs during the heating season which has me somewhat puzzled. It appears as if the interior warmth is telegraphing through the wall studs and the area between the studs is collecting dew/frost. Shouldn’t the converse also be true in the summer?? Ie, the cool air from the conditioned interior space should telegraph through and the moisture from the humid outside air would then condense on the stud pattern??
Just curious if anyone can lend some insight as to why this happens?? Really cheap thin siding?? Poorly constructed??? Normal? (I doubt it or I wouldn’t be asking). Has anyone ever experienced this and if so found a cause?
For what it’s worth, the house doesn’t seem to be drafty and the heat/ac doesn’t run all that much which leads me to believe that the house is reasonable tight. Any thoughts? Conjectures? Meaningless ramblings??
I’m not a pro, just a curious homeowner that likes to know what’s going on so if anyone has any thoughts, let’s hear ’em . . .
TIA, Chris.
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Normal
The studs have an R value of 3.5. The rest of the cavity has a value of 11 or so.
Depending on where you live you can also see this on roofs. I noticed this was more prevalent when I was out in Iowa, than here in Rochester, NY. It seeemd their winters were more damp or frosty than ours here.
It happens to a lesser degree in the summer because there is only a 20 degree difference accross the wall. Even with A/C on full blast there aren't many airborne materials that will condense at 70 degrees. One I know for sure is cooking oils, many restaurants will have studs telegraphed through on the inside of the walls.
What is your peak monthly energy bill for the ehating equipment? (If it is gas, I realize the dryer is on gas, etc. what is the total gas bill in dollars?) What is the square footage of conditioned space?
I have been saying that 8 cents psf per month (peak) is high.
I currently pay 5 cents psf per month in our ongoing renovation farmhouse. Heat whole house to 70, and occassionally enclosed uninsulated porches.
-Rob
*Thanks for the info Rob. And since you asked, the total improved square footage is 1600 (roughly). This is a split level home (tri-level) so part of that space is about 600 sf half way below grade. I guess it just annoys me to see it more than anything. My entire house is electric. Heat pump, HWH, Dryer, everything. My electricity is billed bimonthly and the highest to date has been $160. I don't think $80/month is too bad. The bills are higher in the summer months due to AC. I burn a woodstove in the winter and if I'm diligent, can keep the bills below $50/month from Nov-March. SInce I have all the free firewood I can use, I prefer that to electric. Free heat rules any day. But by my calculations I'm at .05 per sf similar to you for the summer months.The plan is to replace the heat pump with a more efficient unit (maybe with oil backup as opposed to the current electric)when it fails and keep the wood heat also. I like the wood heat even with all of it's headaches. I keep AC on 68-70 all summer (I like to be comfortable) for the cooling as well as to cut the humidity in these miserably humid MD summers. Heat is set on 68 all winter (Oct-??) but doesn't run much when I'm home (evenings and weekends) because I have the fire going. The stove will heat the entire house to a comfortable 70 (Sometimes higher- like 85-90 if I'm not careful!!)with no trouble at all.I don't feel like my utility bills are out of line, but I was just curious of what was causing what I was seeing. Probably wouldn't see it if the house was built with staggered 2x3 stud walls I suppose. I've learned a lot from the folks here just by reading and I may be building a new home in the intermediate future, so I take all of this info to heart so that when I find the right contractor, we can work together to spec a place that I am incredibly happy with. Thanks again.
*Yep you have it right. The interior heat is telegraphing through the wall to the exterior. This is very common with houses built at that time because lots of builders didn't bother to construct with a thermal break. I wouldn't consider this to be defective construction since it was, and still is in some places, the standard.If this bothers you just run the numbers on tearing off the siding, installing a thermal break and residing. Bet you stick with what you have. In short this is normal for Northern areas, but I confess I never expected such in your relatively mild climate.I would be more concerned with air infiltration control than changing my heating plant. Use that wood a lot. Wood brings good exercise in addition to it being free to you.
*Actually Fred, there is a reside job in the future at some point. If we are still in this house at that point in the future, new siding will be installed. (along with my 2 car garage ;) And I will investigate the thermal break issue at that time. But you are right- would I do it today to avoid the telegraphing? No, the money is better spent elsewhere.And just to clarify, I am not intending to replace the heating plant without due cause. But the heat pump is 13 years old (with an avg life of what, 10 years?), so I am learning as much as possible so that I can make a well educated decision when the thing croaks. Thank you gentlemen for your advice and expertise, It is much appreciated.
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I'm not sure if I have a problem or not, but I figured there was no better bunch to ask than you guys. But here is the problem I am about to have:
Over the past several winters, I have noticed that when the temperature outside gets chilly enough, when one looks at the side of my house, you can see the outlines of the studs inside the walls. The siding is frosty/ dew covered everywhere except for where the studs are within the walls. The house was built in '87, traditionally framed (platform), 2X4 walls, OSB sheathing, and (shudder) vinyl siding. FG batts in exterior walls. Not sure if any housewrap of the like was used. I figure, most likely, there is Tyvek or something similar under there.
This problem only occurs during the heating season which has me somewhat puzzled. It appears as if the interior warmth is telegraphing through the wall studs and the area between the studs is collecting dew/frost. Shouldn't the converse also be true in the summer?? Ie, the cool air from the conditioned interior space should telegraph through and the moisture from the humid outside air would then condense on the stud pattern??
Just curious if anyone can lend some insight as to why this happens?? Really cheap thin siding?? Poorly constructed??? Normal? (I doubt it or I wouldn't be asking). Has anyone ever experienced this and if so found a cause?
For what it's worth, the house doesn't seem to be drafty and the heat/ac doesn't run all that much which leads me to believe that the house is reasonable tight. Any thoughts? Conjectures? Meaningless ramblings??
I'm not a pro, just a curious homeowner that likes to know what's going on so if anyone has any thoughts, let's hear 'em . . .
TIA, Chris.