Ceiling moisture where it meet the wall on 2 direct opposite sides of the house.

It's -25 outside today, -50 windchill. I've had this issue in the past, but more than at least a year ago. Getting a wet spot in the bathroom on the ceiling, and in the bedroom directly on the exact opposite side of the bathroom spot, so basically under each end of the same ceiling joist if that makes sense. ( bathroom window facing east, bedroom window facing west) I have a attic hatch that had some minor gaps around it( just sealed it off with plastic) after I saw the leaks. I don't want to open it to go up there to let all that heat in until it warms up outside. The roof has soffit vents and static vents, and a vent in the bathroom which we run all the time during showers and 30 mins after. My only thought is not enough insulation in those spots in the attic? I have no idea.... Why is this happening just now on a record low temperatures? The house is built 1986, 2 story...

 

If the insulation has a gap along the side of the ceiling joist, cold air bypasses the insulation and can cause a wet spot on the ceiling because the ceiling temperature will be below the dewpoint. The problem will obviously get worse and be more noticeable the colder it gets outside.

This can also happen when two ceiling joists or trusses are side by side... as there is a small gap between them that air can pass through. Sometimes ductwork will be hard to insulate around, leaving a gap. Hard saying but you won't know for sure until you can go up there.

 

If you buy or rent a thermal camera I bet you will clearly see the problem. That area will likely show as much colder than the surrounding area. And, if you do get hold of a thermal camera take a walk through your house on a cold day and look at all the walls, ceilings and floors for other spots lacking insulation or air leaks.

 

that makes sense thanks. It's -25 today, we got over a foot of snow 3 days ago, and Saturday is supposed to be 43.....can't wait to see what'll happen then.

 

thanks that makes sense. is it a coincidence that since it's record low temperature, the r rating of the insulation isn't handling it, which is causing this?

 

I don't think that word means what you think it means.

co·in·ci·dence Dictionary result for coincidence

/kōˈinsədəns/

noun

1.a remarkable concurrence of events or circumstances without apparent causal connection. "they met by coincidence"

synonyms: accident, chance, serendipity, fate, a twist of fate, destiny, fortuity, fortune, providence, freak, hazard

The fact that the colder than normal outside temperatures are making this problem apparent is no "coincidence". In fact, the opposite is true... it is the obvious reason.

If you are asking if the problem will go away when it warms up, the answer is yes. Warmer temperatures will make it less likely that your ceiling will be cold in areas where the insulation and air sealing is weakest. The cold ceiling is causing condensation... resulting in the dampness you see.

You could also have a condensation leak in your bath fan ducting but I doubt that would run clear to the far side of the house.

 

that would be interesting. are those the ones that cost around $500+?

 

There are some quite inexpensive thermal cameras available now ranging all the way up to models costing many thousands. Some tool rental stores have them available for rent if you don't want to buy or can't find one to borrow.

 

Thanks, as English being my second language, sometimes I mix some words up. lol. So in order to prevent this in the future, I would need to get the insulation looked at?

 

No worries... like I said earlier, you will just need to get up there and look for anything obvious.. the things we mentioned. (what's your first language?)

Maybe there is a 1/2" gap where the insulation isn't tight... maybe there is a pipe that left an uninsulated space. This is a DIY site, so all those things should be easy for you to look at and figure out yourself. If you need to hire someone, I'm sure any handyman could figure it out.

If someone else will be looking at it, take a few pictures or mark the locations with a post-it note or some painters' tape so that they know where/what to look for.

 

So a 1/2 inch of missed insulation could be causing tbis problem? When I do fix it, should i be using spray insulation around the perimeter of the attic since the space is limited in those spots? And czech is my first language

 

It's hard to say without seeing it... it really depends on what you find. And we dont know for sure what kind of insulation you have. But it's common to use fiberglass batts... you might just need to reposition it, or add a little.

Around the perimeter you often need to have Styrofoam chutes in the rafters, with fiberglass stuffed between the chute and the top plate.

If you have two joists with 1/2" between them and no insulation, spray foam might be the ahswer, but otherwise no, probably not.

Since it is tight, you may want to take some pieces of plywood up to lay on... whatever you can fit up there... 2' x 4' or even 4' x 4' if it fits.

I did some carpentry once for a nice old man who was from Czechlosavakia... he wanted to thank me for my work by giving me some Pilsner Urquel... he said it was the best beer in the world!

 

thanks, ill be going up there when it warms up to see what's going on. And did you like the beer? lol it's the most popular, but definitely not my favorite.

 

The beer was just okay... LOL

One of my favorites is Warsteiner Dunkel. (German)

 

sounds good but never had it. germans do make good beer tho.

so I filed an insurance claim, the adjuster lady came by and put a moisture meter up in the spots where the condensation was... the meter jumped to red and then back to green if it was moved not even a foot left or foot right of the spot... same in the bathroom.... she wrote up the repairs to be made like this, remove old insulation, replace insulation with r38 unfaced batts(don't know what's up there now), remove drywall replace drywall bla bla bla...

im lost on what to do. wait until it warms up so I can actually go up there to see if there is more wrong before starting work on just those 2 spots... how warm should it be outside, to safely go up in the attic and check it out?

 

The colder it is the more likely you are to have condensation on the inside. The best time would be when it's about the same temp inside as outside but I'd just pick some weekend that's above 40 so you don't let all the heat out of the house while you have the area opened up.