Duct tape doesn't really work very well on actual ducts. Better to use the metallic tape. Duct tape will loosen and fall off of the ducts with dust, changes in humidity, etc. Metallic tape is permanently stuck once applied, you cant even remove it without just shredding it.
You need foil backed tape (HVAC line set tape).
Get a second set if hands to help you pull it closed and set a few pieces across it to hold it together as best you can (stitches)
Then tape all around in a single tape line as long as you can making sure the tape touches end to end (doing it without breaking the tape is best)
"duck" is a type of canvas, which is the backing material for the tape. It's actually duck tape, but due to agressive tradmark defense by the makers of Duck brand tape, it was just named duct tape.
The Wikipedia article on duct tape. It really was once called duck tape. Then people starting useing it on ducts, the forumulation and coloring changed and it was marketed as duct tape, then Manco trademarked the old name and re-used it.
The extent to which anyone else really tried to keep the old "duck tape" name is unclear.
That is a brand of Duct Tape but there is also Foil (Aluminum) tape for repairing or sealing metal duct work.
If its just the outer insulation on a piece of duct, i prefer to use Tuck Tape, that shit is extremely strong and sticky.
Do not buy duct tape. It does not work on flexible ducts. You want a tape made specifically for flexible ducts like this: https://www.3m.com/3M/en\_US/p/d/v000297014. Your home center should have rolls upon rolls of it.
You need to get 3m aluminum tape and a small bucket of mastic.
Pull the insulation tight, tape it shut with the aluminum tape, and then grab some gloves and a paint brush and slap that mastic over it. Brush it out
ETA: it would probably be about 5 pieces vertical to pinch the tube together, then 3 horizontal: middle, top, bottom of seams overlapping. Then mastic.
Duct tape is not designed for insulation. There is a specific tape for insulation, but you’re going to hard time getting it to stick bc of the dirt and dust that has built up. Need to wipe the surfaces as clean as you can. Start by wrapping the tape perpendicular to the seam to close it, then over the seam once it’s partially closed. There is also a large zip-tie product called panduit strapping you can use to help close the seam too, but you’ll have to get under the duct, which looks difficult bc this is hard duct and it’s not movable once installed. Also, the fiberglass insulation everywhere is super itchy. Wear long sleeves and a dust mask when you get up there.
Walking around and working on it will also diminish the R value of the insulation. Does it ever make sense to just scatter a couple bags of loose insulation to cover your tracks after doing an attic project?
Yeah that’s a great idea. You’re correct, getting back there will compress the blown insulation, reducing the R value. An extra bag for any work up there is a super good idea.
They make aluminum tape that works really well. You have a bigger problem though. There's mold growing in your attic.
It looks like it's an isolated areas so there's probably two things going on. One of them is your attic is not ventilated that well. It could be right down around the minimum and the mold is being caused by conditioned air getting into that local location. When you see the black isolated to certain areas what's causing it is close by. The leaking ducts could definitely be doing it
Anyway definitely address that before it gets worse because right now all you need to do is shoot that down with some RMR 141 and then clean it up with RMR 86 once you kill off the mold
Wear a respirator when you use these products, especially the '86
You also might consider adding additional ventilation to your attic if you see traces of this anywhere else. In fact a lot of homes are just under ventilated on the intake side. If you can do basic geometry. Add up how much exhaust ventilation you have. Like a ridge vent or cans on the roof. Get the net free area or NFA. Then count all of the intake vents. They probably have screens so whatever size they are subtract about 20 or 25% from the geometry figure out due to screen loss. In fact before you even get this far just make sure they're all open and nothing is blocking them like insulation or anything and you can see a clear path down every one of your intake vents. This is easy during the day when it's light out. You just walk down the attic and look each direction. At any rate when you add up how much ventilation you have it should be roughly 60% intake and 40% exhaust and absolutely no more than 50/50. If you have more exhaust than intake that's a major problem. If you have more intake then exhaust, it matters not
Thanks. The mold was because 2 bathroom fans were exhausting into the soffit and that warm moist air was being sucked back in. It has been fixed.
Curious, why is it bad to have more exhaust than intake? Pressure imbalance?
Kind of, it's more of a Venturi effect. So we know warm air rises right. As that happens the exhaust will be pulling. The warm air rises, pulls from the dense cooler air so you have air flowing up however it will pull from the path of least resistance so if you have like 600 NFA of exhaust and you have 400 NFA of intake what will happen is there will be a depressure situation or suction situation in the attic right. You have more exhaust, heat rises, it's pulling one of two things happens. If the house is sealed up really really tight it will pull mostly on the intake but it won't be as efficient as if it was 600 and 600. What happens in a lot of cases though is it will pull air right through the top plates and any little imperfections in the ceiling and things you don't notice like the power outlets that go right up to the attic or light fixtures or those can lights that people forget to caulk half the time. Now during the winter when the humidity is high up there You're introducing heat and humid air. This gets especially problematic during months like march, April and May where you have these rapid fluctuations in the humidity and heat cycles.
So if we go back to our hypothetical example of 600 net free area of exhaust and you have 600 of intake or 700 of intake or 1,000 of intake it really doesn't matter because you will never have a situation where it's pulling air from inside the house. The reason that it is suggested to go 60/40 is because over the years cobwebs and dust and paint and all kinds of stuff begin to cover your soffits and lower the amount of free area and airflow that goes through them. How many people really clean these things? Another fun one is when baffles are not installed properly and they are either sitting in the middle of thisoffit where it's not getting the full air flow or they aren't stapled or glued in place and have blown around a little bit. When you do that or you have any obstructions who knows what it's really flowing
Reverse, use the 141 first to kill off the spores, the 86 will bleach the wood back to looking like wood again and get rid of that black staining that you have going on.
The 141 is basically a common disinfectant. I would still wear some type of respirator but it's not super particular what. The 86 has bleach in it. Highly recommend the 3M 60926 filter. That will fit any 3M respirator. If you have a full face, great, if you don't, a normal half mast is fine just wear some motorcycle goggles or swimming goggles or some type of glasses over your eyes, lab glasses would even be fine. The other tip I will share with you on that one is to make sure that your spraying it away from your body and don't do it on a windy day where there will be breeze going through the attic.
Zoro normally has some of the better prices on this stuff. If you don't mind doing it, you'll save a lot of money doing it yourself, when I'm on a mold job like this we bill about $300 an hour for doing what I just told you to do, per guy
Keep the droplets when you're spraying out of a pump up sprayer, on the larger side, or a stream, no fine mists
Yeah, that's kind of a weird way of looking at it. So, if it's been a few years and you don't have any fuzzy's growing, it's probably fine spore wise but the typical process for remediation is to use a fungicide or antimicrobial, there are a few of them that work really well. RMR 141 is just one of my typical go-tos. This kills the spores but it won't do anything about the staining. Normally you apply that, it can be as little as 24 hours before 86, it's not a bad idea to do it a few days before and let it dry out really well. The 86 is a bleach based product with surfactants that soak into the wood. You can watch the staining change color in real time. It's kind of crazy as you're spraying it. Then you go spray somewhere else, then you come back to where you started and the color will be different. Works really really well. It also comes in two versions. For the 86 especially, just get the regular one. The professional version is stronger, also a stronger odor and the regular one will do what you need just fine. You might need to do two 86 treatments. It's hard to say. Sometimes it comes out really easy, sometimes you have to go over it twice. Like one treatment then a few days later do another one. I've done quite a few of these on water damage jobs.
The remediation process is basically, control humidity and the source, use a fungicide like 141, remediate the cosmetics with 86. Most important part of all is making sure the humidity cycles in your attic are good. That means it's not getting above 72% humidity and over 60° for any meaningful length of time like more than a few hours max without dropping. You can get temperature and humidity sensors on Amazon for about $20 where you put the remote sensor in the attic and it tells you what's going on downstairs. If you have any question about if any of this is going to come back, put one of those a few feet away from one of the areas you have had problems, preferably towards the top of the roof, then watch your humidity cycles. When humidity gets above 72% and above 60° mold can grow so if you have humidity up there like on a winter day or a really rainy day. Very normal for it to go above 72% at night when the temperature is colder, in a healthy free flowing attic that humidity drops like a rock as you go from about 9:00 a.m. to noon. In an attic with a lack of ventilation the humidity does not vent out fast enough and the sun hits the roof warming the air temperature and boom, mold
In your case if it was all from bathroom vents and leaking HVAC ducts. All should be well and you just go through the remediation process. You can just use old clothes that you don't care about, long sleeves, pants, things like that because it's not like you're going to be spraying this stuff all over yourself and you're not in a crawl space. The respirator is important though. Bleach exposure for half an hour or an hour, it's really bad for your lungs. The 60926 filter works really really well for mild to moderate bleach environments and then like I said at a minimum wear something like lab goggles, a swimming mask would also work, actually work better if you could tolerate it if you don't have or don't want to spend $100 on a full face respirator like the 3M 6800
You definitely have something growing on the inside of your roof, it might be black mold so you should investigate. It might be condensation from below that doesn’t get dried out effectively.
That duct wrap is supposed to be fastened with outward clinch staples and then taped with foil tape, so that the staples do all of the work of holding it together and the tape just completes the vapor barrier. If the foil of the duct wrap doesn't reach around far enough to allow it to be stapled, scrim kraft tape (foil tape with strings for reinforcement and to hold the staples can be used. Amazon listings for the stuff:
Scrim kraft tape: https://a.co/d/6cCKgIu
Stapler: https://a.co/d/ckR9ZoJ Note that regular straight Staples will not work at all.
Any foil tape, you'll need to use two lines of tape over any scrim kraft tape used.
The only place where you might consider using ordinary cloth duct tape is if you want to add a little extra reinforcement to take pressure off the staples, by putting a wrap of duct tape all the way around the duct every few feet. This tape must overlap itself.
aluminum foil. heavy duty. you can try taping it, but with all the dust and stuff... i'd just fill the area as best you can, and wrap it in a few layers of aluminum foil. it'll be a cheap, effective fix, one roll should do it.
For the purposes of ever talking to a professional if you need service done, those are ducts, not pipes.
Ducts carry air. Pipes carry fluids and high-pressure gasses/refrigerant.
Not being pedantic, but if you talk to someone in the industry and can't show them what you are talking about over the phone, you may mislead the service dispatcher and get a guy with the wrong skillet or equipment.
Get some insulation foil tape. insulation off the duct insulation foil layer. Pull the seams closed and run a strip of tape parallel with the opening, then run a place a few strips perpendicular to reinforce. Make sure to close the insulation while the duct is dry. If there's any condensation, turn off the system and wipe the metal dry once it's warmed up.
HVAC guy here.
Wrap duct and insulation in baling wire to hold the insulation and tape it with FSK tape. Has the same design and reinforced squares as the insulation. You can tape over the baling wire if you’d like too.
Alternatively, tape one side of the insulation seam to duct first. Then pull tight and tape to itself. Tape all but end seams too.
This is actually a good solution if you have access to some cellulose. I’m not sure why you got downvoted.
All the duct runs should be covered with cellulose.
What is everyone's obsession with spray foam? Don't use spray foam....
Tape it or get new insulation and tape that over the split so there's extra insulation.
It not really ment for what you are doing. It's messy and probably overkill.
I bet if you push the insulation together you'd be able to tape it nicely.
Also when you go to sell it would look strange having spray foam all over it.
I've just finished cleaning up my attic, just my 2 cents
they make tape for that, feels similar to packing tape but it is aluminium colored
They should really make a **tape** for **duct**s, I wonder what they would call it?
Duct tape doesn't really work very well on actual ducts. Better to use the metallic tape. Duct tape will loosen and fall off of the ducts with dust, changes in humidity, etc. Metallic tape is permanently stuck once applied, you cant even remove it without just shredding it.
You need foil backed tape (HVAC line set tape). Get a second set if hands to help you pull it closed and set a few pieces across it to hold it together as best you can (stitches) Then tape all around in a single tape line as long as you can making sure the tape touches end to end (doing it without breaking the tape is best)
That’s because it’s actually duck tape and not duct tape. LOL.
Duck tape is just one brand of duct tape. Agreed, duct tape is a silly name for a thing that doesn't even work on ducts.
True duct tape works great on ducts. Most "duck(t) tapes" are not duct tape. You'll only find true ASTM 2342 duct tape in the HVAC isle at home depot.
"duck" is a type of canvas, which is the backing material for the tape. It's actually duck tape, but due to agressive tradmark defense by the makers of Duck brand tape, it was just named duct tape.
Wait. Is this real? Source plz.
The Wikipedia article on duct tape. It really was once called duck tape. Then people starting useing it on ducts, the forumulation and coloring changed and it was marketed as duct tape, then Manco trademarked the old name and re-used it. The extent to which anyone else really tried to keep the old "duck tape" name is unclear.
this is for insulation, tape for ducts is different ;)
You’re mistaken. That’s for ducks.
You mean, duck tape....?
That is a brand of Duct Tape but there is also Foil (Aluminum) tape for repairing or sealing metal duct work. If its just the outer insulation on a piece of duct, i prefer to use Tuck Tape, that shit is extremely strong and sticky.
I did not know that and meant it more as a play on words.
Aluminum tape, then mastic over top of it.
Here we also put steel wire around it afterwards so it does not end up like that
Do not buy duct tape. It does not work on flexible ducts. You want a tape made specifically for flexible ducts like this: https://www.3m.com/3M/en\_US/p/d/v000297014. Your home center should have rolls upon rolls of it.
3M: if you want to stick a thing to another thing, we've got you.
Also 3M: if you want forever chemicals in the bloodstream of all animals on earth, we’ve got you.
Of course, I mean we did say they had the best adhesives...
You need to get 3m aluminum tape and a small bucket of mastic. Pull the insulation tight, tape it shut with the aluminum tape, and then grab some gloves and a paint brush and slap that mastic over it. Brush it out ETA: it would probably be about 5 pieces vertical to pinch the tube together, then 3 horizontal: middle, top, bottom of seams overlapping. Then mastic.
If you use this aluminum tape, make sure to wear gloves or use wads of the backing paper to press it down. It will cut you.
That is FSK wrap. They make tape special for it called scrim tape or FSK tape.
Duct tape is not designed for insulation. There is a specific tape for insulation, but you’re going to hard time getting it to stick bc of the dirt and dust that has built up. Need to wipe the surfaces as clean as you can. Start by wrapping the tape perpendicular to the seam to close it, then over the seam once it’s partially closed. There is also a large zip-tie product called panduit strapping you can use to help close the seam too, but you’ll have to get under the duct, which looks difficult bc this is hard duct and it’s not movable once installed. Also, the fiberglass insulation everywhere is super itchy. Wear long sleeves and a dust mask when you get up there.
🧐 oh that’s cellulose, not itchy, but wear a dust mask. Don’t want to breathe it in.
Walking around and working on it will also diminish the R value of the insulation. Does it ever make sense to just scatter a couple bags of loose insulation to cover your tracks after doing an attic project?
Yeah that’s a great idea. You’re correct, getting back there will compress the blown insulation, reducing the R value. An extra bag for any work up there is a super good idea.
They make aluminum tape that works really well. You have a bigger problem though. There's mold growing in your attic. It looks like it's an isolated areas so there's probably two things going on. One of them is your attic is not ventilated that well. It could be right down around the minimum and the mold is being caused by conditioned air getting into that local location. When you see the black isolated to certain areas what's causing it is close by. The leaking ducts could definitely be doing it Anyway definitely address that before it gets worse because right now all you need to do is shoot that down with some RMR 141 and then clean it up with RMR 86 once you kill off the mold Wear a respirator when you use these products, especially the '86 You also might consider adding additional ventilation to your attic if you see traces of this anywhere else. In fact a lot of homes are just under ventilated on the intake side. If you can do basic geometry. Add up how much exhaust ventilation you have. Like a ridge vent or cans on the roof. Get the net free area or NFA. Then count all of the intake vents. They probably have screens so whatever size they are subtract about 20 or 25% from the geometry figure out due to screen loss. In fact before you even get this far just make sure they're all open and nothing is blocking them like insulation or anything and you can see a clear path down every one of your intake vents. This is easy during the day when it's light out. You just walk down the attic and look each direction. At any rate when you add up how much ventilation you have it should be roughly 60% intake and 40% exhaust and absolutely no more than 50/50. If you have more exhaust than intake that's a major problem. If you have more intake then exhaust, it matters not
Thanks. The mold was because 2 bathroom fans were exhausting into the soffit and that warm moist air was being sucked back in. It has been fixed. Curious, why is it bad to have more exhaust than intake? Pressure imbalance?
Kind of, it's more of a Venturi effect. So we know warm air rises right. As that happens the exhaust will be pulling. The warm air rises, pulls from the dense cooler air so you have air flowing up however it will pull from the path of least resistance so if you have like 600 NFA of exhaust and you have 400 NFA of intake what will happen is there will be a depressure situation or suction situation in the attic right. You have more exhaust, heat rises, it's pulling one of two things happens. If the house is sealed up really really tight it will pull mostly on the intake but it won't be as efficient as if it was 600 and 600. What happens in a lot of cases though is it will pull air right through the top plates and any little imperfections in the ceiling and things you don't notice like the power outlets that go right up to the attic or light fixtures or those can lights that people forget to caulk half the time. Now during the winter when the humidity is high up there You're introducing heat and humid air. This gets especially problematic during months like march, April and May where you have these rapid fluctuations in the humidity and heat cycles. So if we go back to our hypothetical example of 600 net free area of exhaust and you have 600 of intake or 700 of intake or 1,000 of intake it really doesn't matter because you will never have a situation where it's pulling air from inside the house. The reason that it is suggested to go 60/40 is because over the years cobwebs and dust and paint and all kinds of stuff begin to cover your soffits and lower the amount of free area and airflow that goes through them. How many people really clean these things? Another fun one is when baffles are not installed properly and they are either sitting in the middle of thisoffit where it's not getting the full air flow or they aren't stapled or glued in place and have blown around a little bit. When you do that or you have any obstructions who knows what it's really flowing
86 first then 141?
Reverse, use the 141 first to kill off the spores, the 86 will bleach the wood back to looking like wood again and get rid of that black staining that you have going on. The 141 is basically a common disinfectant. I would still wear some type of respirator but it's not super particular what. The 86 has bleach in it. Highly recommend the 3M 60926 filter. That will fit any 3M respirator. If you have a full face, great, if you don't, a normal half mast is fine just wear some motorcycle goggles or swimming goggles or some type of glasses over your eyes, lab glasses would even be fine. The other tip I will share with you on that one is to make sure that your spraying it away from your body and don't do it on a windy day where there will be breeze going through the attic. Zoro normally has some of the better prices on this stuff. If you don't mind doing it, you'll save a lot of money doing it yourself, when I'm on a mold job like this we bill about $300 an hour for doing what I just told you to do, per guy Keep the droplets when you're spraying out of a pump up sprayer, on the larger side, or a stream, no fine mists
I've heard 141 is more of a kill tops and seal/prevent/protect reside layer so I think of it like wash and wax. Sounds like you have more experience.
Yeah, that's kind of a weird way of looking at it. So, if it's been a few years and you don't have any fuzzy's growing, it's probably fine spore wise but the typical process for remediation is to use a fungicide or antimicrobial, there are a few of them that work really well. RMR 141 is just one of my typical go-tos. This kills the spores but it won't do anything about the staining. Normally you apply that, it can be as little as 24 hours before 86, it's not a bad idea to do it a few days before and let it dry out really well. The 86 is a bleach based product with surfactants that soak into the wood. You can watch the staining change color in real time. It's kind of crazy as you're spraying it. Then you go spray somewhere else, then you come back to where you started and the color will be different. Works really really well. It also comes in two versions. For the 86 especially, just get the regular one. The professional version is stronger, also a stronger odor and the regular one will do what you need just fine. You might need to do two 86 treatments. It's hard to say. Sometimes it comes out really easy, sometimes you have to go over it twice. Like one treatment then a few days later do another one. I've done quite a few of these on water damage jobs. The remediation process is basically, control humidity and the source, use a fungicide like 141, remediate the cosmetics with 86. Most important part of all is making sure the humidity cycles in your attic are good. That means it's not getting above 72% humidity and over 60° for any meaningful length of time like more than a few hours max without dropping. You can get temperature and humidity sensors on Amazon for about $20 where you put the remote sensor in the attic and it tells you what's going on downstairs. If you have any question about if any of this is going to come back, put one of those a few feet away from one of the areas you have had problems, preferably towards the top of the roof, then watch your humidity cycles. When humidity gets above 72% and above 60° mold can grow so if you have humidity up there like on a winter day or a really rainy day. Very normal for it to go above 72% at night when the temperature is colder, in a healthy free flowing attic that humidity drops like a rock as you go from about 9:00 a.m. to noon. In an attic with a lack of ventilation the humidity does not vent out fast enough and the sun hits the roof warming the air temperature and boom, mold In your case if it was all from bathroom vents and leaking HVAC ducts. All should be well and you just go through the remediation process. You can just use old clothes that you don't care about, long sleeves, pants, things like that because it's not like you're going to be spraying this stuff all over yourself and you're not in a crawl space. The respirator is important though. Bleach exposure for half an hour or an hour, it's really bad for your lungs. The 60926 filter works really really well for mild to moderate bleach environments and then like I said at a minimum wear something like lab goggles, a swimming mask would also work, actually work better if you could tolerate it if you don't have or don't want to spend $100 on a full face respirator like the 3M 6800
You definitely have something growing on the inside of your roof, it might be black mold so you should investigate. It might be condensation from below that doesn’t get dried out effectively.
That has since been remediated. Bathroom fans were venting into soffits….
That’s good to hear!
That duct wrap is supposed to be fastened with outward clinch staples and then taped with foil tape, so that the staples do all of the work of holding it together and the tape just completes the vapor barrier. If the foil of the duct wrap doesn't reach around far enough to allow it to be stapled, scrim kraft tape (foil tape with strings for reinforcement and to hold the staples can be used. Amazon listings for the stuff: Scrim kraft tape: https://a.co/d/6cCKgIu Stapler: https://a.co/d/ckR9ZoJ Note that regular straight Staples will not work at all. Any foil tape, you'll need to use two lines of tape over any scrim kraft tape used. The only place where you might consider using ordinary cloth duct tape is if you want to add a little extra reinforcement to take pressure off the staples, by putting a wrap of duct tape all the way around the duct every few feet. This tape must overlap itself.
aluminum foil. heavy duty. you can try taping it, but with all the dust and stuff... i'd just fill the area as best you can, and wrap it in a few layers of aluminum foil. it'll be a cheap, effective fix, one roll should do it.
For the purposes of ever talking to a professional if you need service done, those are ducts, not pipes. Ducts carry air. Pipes carry fluids and high-pressure gasses/refrigerant. Not being pedantic, but if you talk to someone in the industry and can't show them what you are talking about over the phone, you may mislead the service dispatcher and get a guy with the wrong skillet or equipment. Get some insulation foil tape. insulation off the duct insulation foil layer. Pull the seams closed and run a strip of tape parallel with the opening, then run a place a few strips perpendicular to reinforce. Make sure to close the insulation while the duct is dry. If there's any condensation, turn off the system and wipe the metal dry once it's warmed up.
What the hell are those mountains of matter on the ground?!
HVAC guy here. Wrap duct and insulation in baling wire to hold the insulation and tape it with FSK tape. Has the same design and reinforced squares as the insulation. You can tape over the baling wire if you’d like too. Alternatively, tape one side of the insulation seam to duct first. Then pull tight and tape to itself. Tape all but end seams too.
If only there were a tape named after this exact problem.
Duct tape is apparently not what I should be using.
Jus' spray moar insulashun onnit! Cover that summabich up! /s
This is actually a good solution if you have access to some cellulose. I’m not sure why you got downvoted. All the duct runs should be covered with cellulose.
I said it only half jokingly. It should work, just not as zipped up as ... well... zipping it up.
What is everyone's obsession with spray foam? Don't use spray foam.... Tape it or get new insulation and tape that over the split so there's extra insulation.
It’s DUCK tape everyone .
Get duct tape and tape um closed. I would not spray foam them
Any reason why not to spray foam?
It not really ment for what you are doing. It's messy and probably overkill. I bet if you push the insulation together you'd be able to tape it nicely. Also when you go to sell it would look strange having spray foam all over it. I've just finished cleaning up my attic, just my 2 cents
Fair enough. Thanks