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Why so hot on this ceiling?
Upstairs bathroom is over our utility/laundry room that is only half finished. In the winter we had a leak in the corner where the plaster fell down. Shoved some insulation up there when we replaced it & had the roof fixed. The roof gets very narrow as it ends around where the window is, so we’re unable to see how well insulated it is above the rest of the bathroom.
While the light has a vent fan, it has never turned on in the 7 months of owning this house. There is a pipe above on the roof, but we think it might be the roof vent, not a bathroom vent.
What else could be making it THIS hot on the ceiling?
Discussion
The sun ☀️
To me that looks like a bathroom vent assuming you are in fact in a bathroom. That means right above there is some kind of pipe which should (hopefully) exit outside on the roof. (You should be able to go outside and see the spot on the roof.). With a pipe there, there’s nothing else insulating so that area is going to naturally be a little warmer. There’s not really anything I’d anticipate you can realistically do. Would just make sure there are no air leaks around the ventilation where it goes into the attic and if you’re able make sure there’s adequate insulation everywhere else.
There are things that can be done. The bathroom fan/vent should be insulated. It probably isn't insulated correctly. They rarely are. The box in the attic that houses the fan should be air sealed around the drywall cutout and have insulation covering it. The actual vent run that makes it's way outside should also be insulated. If done correctly there should not be a major difference between the vent fan and the surrounding ceiling.
How hot is it outside? Is it possible the hot air from outside gradually heats up the vent?
Virginia, so the highs are well into the 90s + humidity so maybe
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lol. sorry I didn’t think the ceiling was supposed to be almost 100 degrees indoors?? this is our first house & neither of our parents have ever had this problem. sheesh!
Yea, yea, okay. Sorry.
Why are you like this?
Booooo
Oh snap son!!!
Don’t read the ceiling fan. As others have said, there won’t be any insulation above that. If other readings around the ceiling are still super high, you need to have your attic vented/insulated.
The fan If installed properly should not have a large delta gap between it and the rest of the ceiling. Chances are though it simply wasn't installed correctly. They rarely are. The box in the attic that houses the fan should be air sealed around the drywall cutout and the exhaust vent that actually makes it's way outside should also be insulated and the entire fan box that is visible in the attic should be covered in insulation. They are almost never are.
Solid advice for OP to also get this checked out. If they’re lacking insulation to the degree it seems, chances are there’s some other issues as well. Best to check out the entire attic space for potential problems while you’re up there!
Yep, since attics aren't fun to be in corners are cut in there often. Either by homeowners who are well intentioned but don't know how to address certain issues or by contractors that know most people will never check over their work and assume everything was done correctly.
Between vents and insulation, which one is better?
I have a similar problem with vaulted ceilings and only 4 inches between my roof and ceiling (mid century modern style home) so not enough room for both. My roof is missing soffit vents and ridge vents, and insulation is nearly non existent (built in the 50s).
UPDATE: thanks to some of you for the helpful responses. we’re going to open up this vent and see if it’s appropriate connected to anything or just for show when we have more time to deal with the insulation mess that comes with
as for others good luck living in the swampy hell that is your upstairs?? idk i hate summer!!!
Had the same issue where the ceiling was much warmer. Turns out our attic fan wasn’t working. Might want to check on that if you have one.
I'm having the same issue and I'm 99% sure I need to blow in more insulation.
what are the ceiling temps in adjacent rooms? your best bet is to get a thermal imaging camera. klein makes one that attaches to your phone, or amazon
but there’s likely no insulation around the duct for the fan, the fan housing is a metal box so it’ll retain any heat as it rises
Put a thermometer in the attic and you will understand
HVAC tech here
When you had the flooded out corner did you observe the contractor in their daily work at end of day or before sealing up the area?
Plaster retains a lot of heat due to its insulation properties but with proper air flow shouldn't be reading that hot unless the contractor for either the plaster or roof really messed up their job.
Easiest way to know their level of work is check and see if permits were put in with the city inspector.
I'd recommend renting a camera snake as well and checking the ceiling crawl space and seeing how much insulation is actually their to what it should be.
1) it’s an outside wall. 2) guessing the insulation around that vent wall/ceiling is inadequate 3) if it is vented to the outside wall or roof you pretty much have a hot air intake (they have those little flappy-do’s but they not air tight) I would inspect the insulation and just make sure nothing up with it. Could have been pushed aside during the vent install.
Turn on the bathroom or laundry room exhaust fan. Leave it on.
Absolute temperature. The plastic is more dense holds heat . Paint dissipates heat faster I suppose .
Your attic should ideally be no more than 15 degrees hotter than outside if it’s properly vented
So if it’s 80 outside your attic ideally shouldn’t be warmer than 95
Is there insulation above that ceiling?
Heat rises and sun exposure on the roof.
I feel like ppl need to take some sort of construction basics. Bro, you got angry ghosts in the ceiling obviously.
Cause heat rises and needs a way to return back to unit
Heat rises , Lack of insulation , Lack of ventilation ,
Someone growing stuff up there .
Looks like a exhaust fan. If it is running you might be picking up the motor heat.
Depending on the type of roof you have say a hip roof - if you stuffed insulation at the ends then no outside air can come into you’re attic this leads to hot stagnant air
Heat rises!! lol plus you insulation and ventilation probably suck to.
Crappy insulation or lack there off and heat rises
Install an attic fan.
It's hot, you've been thinking about a relationship with the ceiling for a long time, buy a fan ☺️
Physics
Really need to know the ambient room temp as a point of reference. Also maybe the floor and walls
Room overall ranges between 30-65% humidity depending on if the ac is on. Floors are coming in at floors & walls are 80 degrees during the hottest part of the day.
Hold on, where are you getting those numbers from? Humidity levels at or above 60% develops mold and is a health hazard. In Virginia it would be very rare to get it down to 30%, and a swing that big in humidity is going to cause issues.
EDIT: OP I'm genuinely asking to help out, not messing with you or anything like that
We have one of the little temperature and humidity gauges you can hang on the fridge typically. like this
Lowest it’s gotten is about 35% in there when the AC is on. The vent in here is the first vent connected to the supply line downstairs, so it gets the coldest.
Those gauges are around +/-5% if you're lucky. Usually more like 10%>
Warm air rises…
Heat rises, last time I checked
Heat migrates towards cold regardless of direction. Hot air will rise unless trapped in a confined space.
Convective heat vs. conductive heat. Both contribute. With air, if allowed to move, the hot air will rise. Once all the air is at the same temperature it does not matter.
I recall living, many summers ago, in a house with ceiling fans but no AC. During the worst days, the fan would only replace hot and humid air with equally hot and humid air, so it felt more like a convection oven.
On the topic: that’s probably the trap door to the attic, which is likely not insulated. The T differential is telling you how much heat from the attic is NOT being radiated through the ceiling
Heat rises, has for years…
Attic are hot
Because heat rises???
Approximately 94 million miles away is a massive ball of super hot plasma. Hope this helps
Lack of insulation or proper ventilation of attic space
Only helpful answer here so far. Why is everyone so mad here.
Or both simultaneously.
Between vents and insulation, which one is better?
I have a similar problem with vaulted ceilings and only 4 inches between my roof and ceiling (mid century modern style home) so not enough room for both. My roof is missing soffit vents and ridge vents, and insulation is nearly non existent (built in the 50s).
4" between your roof and ceiling as in, between the tops of the joists and bottom of the rafters, or between the actual roof decking and ceiling?
Basically there's a 4" cavity between the backside of my ceiling to the underside of my roof. So it's pretty tight. I believe I could have foam sprayed in but if I understand correctly they typically blow in 4" so that would fill the void and make vents ineffective. I'm trying to figure out if I should do vents or insulation sprayed in bc I don't think both are an option
I have often seen insulation added on top of the old roof decking during a re-roof in this situation. I wouldn’t expect those joist bays are vented at all, but an insulation contractor would be able to tell you the best course of action.