Hey /diy/.
I put in some insulation on a sloped potion of my home about a week ago. I was going to finish up the last few spots and put up the drywall, but I noticed these wet spots on once piece.
(cont)
>>903579
Just to make sure it wasn't a leak in the roof I pulled back the insulation, as shown here.
It's a sloped roof, as you can see. The portion of roof I exposed was damp, with condensation drops running all along it. Far as I can tell, it wasn't a leak, but just the condensation.
>>903579
Close up, you cankind of see some of the water droplets.
My question is: how come this isn't happening with any of the other batts, and how do I prevent it with this one? Why is it happening at all?
>>903579
You should try to reverse your insulation (paper on top).
Otherwise, go buy some specific plastic film against condensation in hardware shop.
>>903591
But it's only appearing on one piece?
is it cold where you live? the warm moist air would travel through gaps in the insulation at the joints and condense on the cold roof. but the picture in op looks a lot like an ink stain from manufacturing.
>>903597
It's for sure damp
>>903600
Dunno where you live but here in UK you can get insulation with foil on it, creates a barrier. Does the space where the insulation goes have any ventilation at all? Air vents or airbricks? Warm humid air meeting cold air is always going to cause condensation, you need to vent the air somewhere so it doesnt have the chance to condense. Do you regularly open your windows to circulate the air? Try a dehumidifier temporarily see if it clears it up, if it does you need to sort out venting.
>>903610
Op's solution isn't a vapor barrier, his solution is to not try to turn his attic into a finished room. He's always going to have a humidity problem. It needs to remain an attic and have good ventilation and insulation on it to keep his home warm.
It looks like he's pretty deep into it already though, so he's fucked pretty good.
>>903610
I might hve to take it down and put up a barrier manually. I don't see how I can have insulation in the spaces and still have them vented.
>>903620
It's not an attic. It's a shitty old house that had a room added on; the pictures were taken in that room.
Look closely at the second picture: the joists are holding up the roof, which is directly above the baseboard planks. As of right now, the insulation is hanging between the joists and pressed directly against the baseboard planks.
I'm trying to turn the room into a finished room, in short.
>>903620
Op, you need to pull all your insulation down and figure out how to vent your vaulted ceiling properly.
If you're a complete monster, then complete your project and flip the house. Then watch for it on Holmes Inspection (or equivalent show) in 5 years or something. You might get taken to court for damages. You are creating a nightmare for yourself or whoever owns your property later. There will be mold, damp, rot, structural damage, all sorts of shit.
>>903629
Short of taking off the entire roof and constructing the necessary space, I just don't see how this would be possible.
Is there an alternative? Why does the wall insulation in the cross section not need ventilation, but the roof portion does?
>>903636
cause the sun beats down on the roof and heats up the air under the roof deck. Now a days a lot of high end builders are starting to put air spaces on the walls
if you use a real vapour barrier instead of that shitty craft face it wouldn't happen.
>>903644
The vapor problem, I believe, is due to the temperature difference between the wood and the insulation applied directly to it -- see picture #2.
If I apply a vapor barrier to the wood (which is the baseboard for the rolled roof directly above it), would that mitigate the problem?
>>903652
http://www.ehow.com/how-does_4674255_vapor-barrier-work.html
It depends on your climate. It almost definitely isn't going to help in this situation. If you needed a vapor barrier it would have been installed already. You're trying to use one in a space where it will just make it even worse. It might keep water from showing up on your drywall or insulation, but it will actually be making everything worse by keeping the water next to the wood longer.
>>903654
>>903654
>>903654
Goddamn this piece of shit house, and goddamn the idiot who built it.
I appreciate your candor, anon.
Do you have any suggestion for how the fuck I'm going to insulate the roof, then? The gas fireplace is in that room, and it's our primary source of heat. I can't just leave it uninsulated -- the cost of keeping it even barely livable was ridiculous last year.
>>903673
where do you live anon? not your address, just a general area of the world. we need to know how cold / hot it gets there.
>>903673
Some random ideas.
You're going to need a ventilation space against the roof, bottom line. Unless you can figure out a way to vacuum seal it anyway. If air gets in, water gets in, and the only solution is to also let it get out. You could build a frame or mesh or something to hold the insulation a few inches from the roof. Then you'd need vents for each joist cavity at the peak and the bottom of the slope. That should prevent condensation from sticking around long enough to cause real damage. You may lose a couple inches of height from the roof but this is going to be required.
Just in case though, I'd install it all as panels that can be removed and inspected easily. 1/8" plywood or luan would be light and just strong enough to support some insulation pads. A couple screws is all it would take to remove and inspect each joist cavity. You could maybe use acoustic tile or something to disguise the panels, otherwise it would be ugly, but you'll feel a lot better knowing it's easy to fix if needed.
>>903677
>>903675
I'm in region 4. Coldest it got last year was 15 degrees.
>>903677
The previous owner seemed to be trying to do something similar. He installed ribs running lengthwise along the joists and put foam insulation into that, about 1 inch away from the roof.
Where he went wrong -- and where it's going to be a colossal pain in the ass to figure out -- is that he didn't have the openings on either side of the slope. I don't know how I'm going to do that and have it lead to the outside -- I'm going to have to redo a potion of the exterior wall on either side of the room.
>>903689
>region 4
wat???
what country? what continent? this is the WORLD wide web
>>903692
What he said made sense to any US builder.
His house is made of sticks and wallboard so US is pretty safe. He called a house from the early 1900 old/ancient, almost definitely US.
>>903697
Cool graphic. Never knew there were building regions.
>>903697
ya I guess I should have known, only americans think they are the only people in the world.
>>903712
Is there a group of americans that infiltrate French image boards and post 'lol lrn2 imperial faggots' or 'y u no 120v france? Superior outlets, time tested'? What the fuck are you doing here complaining about the dumbest fucking shit?
>>903710
I'm in zone 7? maybe... I'm actually in Canada. The primary function of insulation here is to keep heat in as I guess for you too. This is how we do vapour barrier here.
>pic related, the best I have on me.
The insulation is separate and placed in the cavities, then the 6 mil plastic is placed over the insulation just before the drywall. But it's not an after thought, it's carefully planned out and plastic is placed behind the partition walls (the half osb half plywood one) and behind electrical boxes. Then all the joints are taped with really expensive tape. When it's done right it should almost be waterproof.
The ehow link states that the only building codes that require vapour barrier are out of date, which is laughable in Canada. Here it is very strict and only in the last 20 years or so. We build our houses air tight and the only ventilation is well calculated, intentional, and mechanically activated. The air that a fire place or bathroom fan removes from the house needs to be replaced with something and this isn't the 1900's anymore so we don't expect that to be a drafty window.
Anyways that's a little off topic as it's for new house construction. If your main concern is to keep heat in then take advice from a Canadian, the vapour barrier goes on the warm side of the insulation not behind it. Also the paper facing on your insulation sucks at being a vapour barrier, because it's paper!
>>903723
my bad
>>903722
>infiltrate
Infiltrate??? Ya I'm part of a group that snuck in here to troll all the americans. I'm defiantly not reading these boring threads to try and help people, who in turn can't answer simple questions. And I'm not frustrated that this board is full of threads made by people who expect everyone else to have all the answers but never provide any answers to other people's questions. No I'm just a troll.
>>903727
How do you think you're going to help people if you don't know what an insulation region is? Have you ever even googled this shit?
>>903732
because I don't live in america you dumb shit. do you not understand that.
>>903735
How the fuck are you going to help people if you don't know what the fuck you are talking about jesus. If you know fucking anything about insulation or vapor barriers or how construction works in the US, where op's problem exists, saying 'region 7' wouldn't have been weird to you. And yes, maybe if you're on an amerifat image board maybe it's a safe assumption to make that we're all talking about the US?
Anon also innocuously gave you the information you asked for and you still turned into a butt keked eurotard.
>>903723
The problem here is that there's condensation being created between the "wall" (in this case, the roof), and the insulation itself due to temperature difference. The surface of the insulation facing the roof was wet when I took it down because of this.
>>903739
where in the op does he say region 7? he doesn't until halfway through the thread in which point I'm already here. Also where the fuck does it say that 4chan is an american website? It's even owned by a Japanese man, you dumb fuck. Which bring me back to my original comment, only an american is dumb enough to forget about the rest of the world.
>>903752
You never gave any fucking good advice in the thread though.
>>903697
>>903689
>>903692
And were all fine.
>>903712
Here you turned into a euromad faggot for no fucking reason. You are cancer. Fuck you, no one wants your 'advice' you didn't help shit and just started an off topic shit storm with your eurofaggotry for no fucking reason.
>>903746
Yes. Which is why you want the vapour barrier on the inside, to prevent the humid air from traveling all the way through the insulation and condensing. If you put vapour barrier on the back of the insulation the warm humid air will still get behind the insulation and just condense on the plastic and still get your insulation wet.
I found this picture to show what I'm taking about. The dew point, the temperature at which the air dumps it's moisture, is somewhere in the middle of the insulation. So you want to stop the inside air from getting that far.
>>903739
We don't have insulation zones in Canada either, as least not that I've ever heard. It's all the same, cold.
>>903761
So placing the vapor barrier where the paper in the current pictures are would put the dewpoint somewhere in the house?
double your 2x4s so you can drop the insulation down some to make a gap it will solve your problem without loosing much ceiling height
>>903819
That's not a terrible idea. I'd still have to find a way to vent it outside, but I'll certainly consider that one.
Here's a way you could vent it outside without cutting a bunch of different roof vents. It's important that you don't drill the holes too big or it will compromise the structure. 1" should do it. I don't know how the rest of your house is built or vented/not but I'm guessing it's not built to today's standards so doing that on one little part of the roof is a waste of effort, IMHO. Get some venting in, but don't go crazy.
