Help. I just discovered we’ve got condensation on the cathedral ceiling and recessed lights in our greatroom. Here’s the history of what’s been done. If you can, please let me know what’s causing this. And, more importantly, how I can fix it.
Last summer I stripped the drywall from the ceiling in the gr. I then put in various IC recessed lights & replaced the drywall with Armstrong Woodhaven “White Wash” tile. I applied these perpendicular directly to the trusses. Last fall I blew in Owens-Corning Fiberglass insulation throughout the attic – probly 7 – 10 inches – over the existing insulation. The roof has a ridge vent and the soffits are vented with those blue styrofoam thingys (I don’t know what they’re called).
This is only happening in the greatroom with the tile. The bedrooms & bathroom are dry (at least that I can see). I’ve been out of town and my wife has had the air on non-stop for five days. (She’s 50 and is always hot – not in the good way). The air is just a window unit in the gr so the air is consentrated in that room. As soon as I came home & discovered this we put on a couple fans to move the air and the condesation immediately dried up. However, I realize this is not the cure as obviously we will not always have the fans running.
Thanks for any help you can give – unless yer gunna tell me I don’t have a good enough vapor barrier & I need to rip out the tile and redo the insulation.
Replies
A little more info
Where is this house located?
How's the humidity in the house? plants galore? constant pasta cooking, hours of simmering that stinky stuff in a post on the stove?
Were these cans, besides being IC rated............the sealed housing type?
If the condensation is localized around/below the cans, if there's slope to this greatroom celing?
Do you burn these cans often?
Are the tops of the cans exposed or covered with insulation-how much?
More Info
We are located in Mid-Michigan.
I don't the exact humidity levels but w do not have many plants, no pasta boiling or excessive showering being done.
The cans are the sealed housing type.
The condesation was pretty much everywhere across the ceiling. The ceiling is sloped.
We don't burn th cans often - the few hours in the evening while watching the Tigers lose. And when they are on they are dimmed.
Tops of the cans are covered approx. 4 - 5 inches.
Your answers are as mystifying as the Tigers collapse..........
As has been pointed out, my questions re. the conditions were more apt to be asked in the winter. With the sealed cans, the ins. above, and our weather in the area (NW Oh/Mid Mi.) it seems unlikely that condensation would occur. The only oddity is the Armstrong panels without drywall above. I've installed a variation of the Armstrong Woodhaven product and didn't have drywall above (in a first floor fam. room/kitchen) and had no problems. Condensation would be a killer to it, it's composition a cross between MDF and reg. ceiling tile. (not quite as dense as sheet MDF.)
Chance you can take a close-up and overall picture of it and post it here?
Deevbub - The problem is that you created a ceiling that has no air barrier or vapor barrier, and is poorly insulated. The air conditioner is cooling the room, drawing down the relative humidity. Outside (hot humid) air is free to move through your attic, your insulation, and your ceiling and condense on the cold surfaces of the cans and ceiling tiles. Becuase the RH indoors is lower than your attic vapor pressure is also drawing more moisture towards your ceiling.
The easiest solution may be to drywall the sealing, right over the old tiles and seal the can housings to the new drywall with foil tape.
I'd suggest sucking out the fiberglass and blowing in cellulose to fully eliminate the condensation inside the can lights.
Calvin - you were able to use those tiles in the first floor because they were not acting as a thermal or air barrier.
Well... maybe...
unless yer gunna tell me I don't have a good enough vapor barrier
You need to stop the warm, moist air from reaching the cold, condensing surfaces, or prevent the cold surfaces from getting so cold.
Well maybe not
unless yer gunna tell me I don't have a good enough vapor barrier
was my attempt at humor. It obviously didn't translate.
It sounds like the great room is pretty cool, but unless I'm wrong, there is high humidity in the house. My easy answer is to run a ceiling fan non-stop. That will dry the ceiling and cool down the wife
If the room was pretty cool (thermally and relatively) he probably wouldn't have the problem. Yes, high humidity (relatively) can result in the condensation. Fans circulate air, they don't dry the air. They may mix air so there is less temperature differences and indirectly eliminate condensation.
Running the fan non stop w/out understanding the problem is like running your furnace non stop to compensate for the window being wide open. Which I admit, some people would do that. Solutions to problems require a clear identification of the problem. Otherwise you are putting bandaids on it. With the information given, it is a bit difficult to determine clearly what the problem is ... the symptom is condensation ... the problem is a bit more elusive.
As some of the Captain Obvious's pointed out, the ceiling is relatively cool and the room humidity 'somewhat high' ... so the condensation occurs. Why? that is the question ... which requires more knowledge of the conditions ... hence the reader's questions to the OP.
Armstrong says not to have loose-fill or batt insulation directly behind the Woodhaven planks--I don't know why they say so, and don't know if that's a factor in your condensation problem.Could the product be porous enough that it allows the warm, humid attic air to pass thru and condense on the cooled surface of the ceiling?
You don't indicate where precisely the condensation is located.
Keep in mind that the air in a large room comprises an actual climate system. In the giant VAB where they assemble the Space Shuttle they actually need special air conditioning equipment to keep it from clouding up and raining inside. You have a smaller version of the same thing. Warm, moist southern breezes (from the rest of the house) collide with the arctic air mass (from the AC) and a "storm system" results. At the "frontal boundary" between the two air masses there will be condensation (clouds/rain) if the warm air is moist enough. This can happen regardless of the insulation of the roof, vapor barriers, etc.
Assuming there is no other contributing factor, you need some technique to stir up the air better and prevent the "frontal boundary" from forming.
I'm a bit confused. We do need to know location (i.e. 'climate'). How is it that we have a vaulted/cathedral ceiling and an attic?
I'm puzzled ... you describe a potential issue w/ e.g. recessed cans ... but you talk like you are in a cooling mode (i.e. warm summer). Warm air rises. The cool air tends to stay down ... unless you have good air mixing which isn't normally part of a small room A/C unit.
Circulating air means you have 'scrubbed' the surface enough to temper the condition causing condensation.
But ... that is what is a bit confusing. In the summer cooling mode, the ceiling will tend to be the warmer surface (cooler in the winter).
Not sure why you didn't hand drywall for the ceiling ... even if you were to cover it with ... what is it? acoustical tile/panels?
If you were in the heating mode, the condensation makes sense ...
need to think about this a bit more and read some of the other comments.