I have a two story family room where I am getting an occasional leak out of one of the recessed lights. There is no leak when it rains but rather the leaks occur at random times when it has not rained for even a week or two.
The amount of water is just enough to wet a 2 inch circle on the carpet, like maybe a quarter of a cup. It does not have much of an oder either though might have a little yellow tint.
The leak comes thru one of the recessed lights. It is a fully metal square boxed recessed light between the ceiling joists, the attic is above the light so it is fully accessible from above. When I go into the attic to inspect the light there is no water on the light or anywhere near it when I remove the insulation. I have mouse and rat poison in the attic that I placed up there in the fall, a small portion was eaten shortly after I put it up there.
I don't see any mouse dropings near the fixture. I don't see any way to get into the can for any critter, though it does not take much for a mouse. I also banged on the can and got no animal reaction.
First off, don't worry about your roof, it's fine. The problem is one of condensation. The light gets warm when it's on and the air in the attic is cold and likely very damp. The combination causes a great deal of condensation to form at certain times. This is likely aggravated by warm air leaking up around the light itself and into the attic. That leak in the vapour barrier is where the water is coming back in.
I'm willing to bet if you double check the vapour barrier and add more insulation above the light the problem will go away.
Join Date: Aug 2004 Location: Mid-Michigan Posts: 77
re: Strange Attic Leak
condensation?
maybe it's not fully insulated around the fixture, or a small break in the insulation, and you're cooking spaghetti which puts a lot of moisture in the air, and the heat from the light bulb is making the light housing warm, allowing the moisture to condense on the inside of the housing, and sometimes there is enough of it to actually drip.
can you get to the bulb side of the fixture to inspect it the next time it happens?
just a thought...
interesting, I have 3 lights in that area, at least one has insulation on top but not the dripping one. We have lived in the house for 12 yrs since it was built and never had this happen. Does warm very dry house air exacerbate the condensation? As I have not been running the humidifiers.
I will see if I have piece of insulation to put on top and see what happens.
OK, I really don't have an off hand cure for dripping lights, but MURF!!! Vapour, is that Canadian slang for when you are across the table from a very proper lady or something??? !!!
I agree with Murf. By the sounds of it you have good cross ventilation which is why you're getting condensation. Just to be sure, verify that the outside air temp is the same or very close to the attic air--the roof structure is only meant to keep the elements off the house not provide insulation or keep heat in or out.
A friend had a new home built that had 2" of ice on the inside of the roof sheathing and less in other places. His dryer vent and bath vents exited into that are where ice was thickest. Mold was forming too from past years and the sheathing was sagging.
A 2500sq ft home with only three roof vents and no soffit vents. Long story short the builder tripled the number of vents and the problem went away. Imagine that.
Dennis when we have can lights in an attic we build a box around it about 18" sq made of 2x6 then loosely cover with insulation. Just for safety in casesome one puts a too hot of bulb in the fixture.
Pics Join Date: Sep 2007 Location: West of Toronto Posts: 1318
re: Strange Attic Leak
One part of the explanation is, as said, condensation. The other is heat conductivity. There's less liklihood of condensation on insulative materials like wood or fabric, more likely on conductive ones like glass or metal.
So one solution is to make the metal less conductive by packing insulation around it. The other is to get a humidistat for the area, and if it shows high (generally above 30% relative humidity), control it with ventilation or a fan. (Without getting into dew-point measurement, the colder it is outside, the lower the humidity has to be in order to prevent condensation.)
Third, if the problem only occurs after the light has been on, leave it off, replace the bulb with a compact fluorescent, or (very carefully) install a heat deflector above the bulb such as aluminum foil.
Depending on air movement it will do this without the light on. Just the difference in the in house temp and the attice temp. Air leaks around recesssed lighting happens. Here it was (not sure if still is) code did not allow insulation over recessed lighting due to heat built up.
Made a mistake when installing exhaust duct in one bath room with non insulated metal running straight up. No problem except when attic is cold (about freezing or colder) then the can be a good amount of dripping on top of toilet seat. Made us wonder about the puddles on top of the seat until one day the water dropped on one of us.
Kenny that vent pipe should exhaust into a roof vent or the air will still condense in the attic like I mentioned earlier. Insulating the pipe does as you say help.
And that puddling on thr seat thing---yer supposta lift the seat.
Speaking of toilets, didn't you tell me that one time your bathroom caught fire? But...luckily you put it out before it got the to house. Lol
Kenny that vent pipe should exhaust into a roof vent or the air will still condense in the attic like I mentioned earlier. Insulating the pipe does as you say help.And that puddling on thr seat thing---yer supposta lift the seat.Speaking of toilets, didn't you tell me that one time your bathroom caught fire? But...luckily you put it out before it got the to house. Lol
In our normal warm weather venting to the attic works well. Two of ours vent to the eaves which allows any condesition to drip or ice up as temp may be on where either will cause no damage. Our bathroon has a very high roof line above it and it vents to outside vent but the bare metal the temp had already dropped before it gets outside.
As to the fire you are correct, but you never did tell me was what was the cause of the fire...what you were smoking or what you were releasing. Has all the hair grown back?
Well I could have said yes, we place all outhouses in Washington. You pick the one you like best.
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