This year I air sealed and insulated all my ducts and pipes. What a difference! No longer heating my crawlspace and all of that warm air is pumping into the house where it belongs!
Nashua 327 is a mastic based tape which works well. I have always considered mastic sealed joints to be the "RIGHT" way to install/fix a duct system. For those who say the Nylon/fiberglass webbing is "Overkill", apparently do not understand adhesives/glues/epoxies. ANYTIME you can add the reinforcing webbing it does add great strength to the adhesive, making it more durable against everything, including vibrations, clumsy cable guys etc. You may not want to spend the time and effort to use the webbing, but in my book it gives the best job possible...HVAC 30+ yrs.
Well.... "Simple and easy" if the duct has been pulled nicely out of the wall and is in your hands. Excruciatingly difficult if you also have to find the leaks on ductwork inside of walls and/or layers of insulation, expose the ductwork, seal it then re-insulate or reinstall it inside the walls. Before everyone runs to the hardware store to buy mastic sealant, make sure you know where your main leakage points are and be assured that you can access them easily or you might night want to DIY this project. That said, I DO know exactly where the leaks in my system are and found this video very helpful so THANK YOU!!
I encapsulated my crawl space last year. I just noticed the dryer vent connections down there were terrible. So this was a great overview of mastic. It should save me some on my AC when I get that sealed.
I just came across your channel as I was searching for mastic duct sealant. Great videos. I hope you start up your channel again. A lot of people in my neighborhood have been fixing up their homes since the start of the pandemic.
Look at you go Corey! Nice video. I've been in the sheet metal industry for more than 30 years and I can't preach enough about how important it is to seal duct work. I never thought to use the sheetrock tape, great idea. I wouldn't typically use it on the commercial jobs I work at because time is money but home projects for sure. I would also recommend using the sealer on the snap lock seam going length ways on the duct. Wiping off the duct is a must. Like I said. Nice video! Be safe! Phil D.
20 years ago I had my basement refinished. I added 5 vents down there and specified no duct tape in the project on the contract. Their HVAC sub said it didn’t matter the heat was still going into the home. For other ridiculousness I told them not to let him back on the job site. It’s to bad when someone has done something for 30 years but will not learn something new.
Thanks Corey for this great informational video. You can learn anything on RUclips because of creators like you. I have two vents that need attention, this video gave me the confidence to be able to do the job right.
We just had all metal ductwork put under our house in the crawlspace. Our HVAC contractor did not use mastic but instead used the foil faced HVAC tape to seal all joints and seams.
Thanks for the comments! For years, HVAC installers have been using DUCT TAPE to air seal the joints in duct work. Strangely enough, duct tape is not made for working on ducts because the glue can not handle the heat. Energy Star estimates most homeowners lose 20% of the money they spend to heat and cool their homes because of leaky ducts. The air disappears into the walls and attic spaces without reaching your living space. This is a cheap way to save money and make your rooms comfortable.
Great video! I'm going to run out and grab some mastic for this weekend's project. Have you ever done any work around insulating fireplaces. I have a screen that seems to leak like a broken window. What insulation was there when the house was built seems to have fallen apart. Any ideas on what would be appropriate to use in that space?
Hi there, great Video. I'm in the process of starting to finish my basement. I have duct work in my floor joists for both upstairs and basement. The Permit I am acquiring tells me I should use Low Wall heating here in ON Canada, something like what is in in your video. Is that the best way, i.e. remove my existing duct work for my basement and run duct work in my studs for each room.and of course leave the duct work for the upstairs. Should the cold air intake be higher than the warm air. thanks
Local HVAC tech quoted me $4500 saying my ducts needed replacing, but it's obvious they only need sealing costing a couple hundred bucks DIY and a few hours work. I was also quoted $4500 to have the blow sealing done. Yea, not happening. Thanks for the info.
Idk anyone with these type of metal ducts exposed, but it's a bitch to do, if a company if going to reseal them, they might as well replace them if the sheet rock is coming down, they probably have mold in them anyway if they're old. There's a reason they don't want to just reseal them.
I'm putting together a wood shop dust collection system and realize the fasteners are intended to immobilize the pieces in relation to each other and that the main trunks are best assembled on the floor. How long will it take for the mastic to dry or cure thoroughly enough to be roughly handled without transferring where unintended?
I have an old house with pipe and conduit penetrations through the duct work. Now sealed with what I think is asbeotos/tape. How do I reseal these penetrations after getting asbestos professionally removed? Fiberglass tape and mastic?
my mastic jobs that I have owned over the years looked like broken arm or legs casts. Smooth and rock hard all around the steel. Maybe the old school way of doing it so it looks good.
Must depend on jurisdiction. As far as i have discerned resi has less sealing than the POS condos I worked for the last 8 months. Resi tends to be piecework where I am which means poor workmanship from my experience.
Thanks Corey. Great video! Some things just make sense and putting drywall tape on does just that. After all mastic is in putty form as you are putting it on just like drywall mud. On my house, which was built in 2006, they used DUCT TAPE and then covered the DUCT TAPE with mastic. I wish they had used mastic by itself as the duct tape that is mastic covered is coming off and allowing massive amounts of air to leak out. I have fixed a few of the largest leaks and will fix the rest soon.
Should I just use mastic only? Or should I use premium foil tape then mastic. Or a thin layer of mastic, then tape and cover with mastic again? I'm trying to figure out what is best option and planning on doing this soon.
Question. My supply plenum became unseal in one long area , can I just add more mastic and fiber tape to seal it? How long do I let it sit before it is dry and can turn on the AC?
Great video! I'm trying to find a solution that's cheap and leak free for my square ventilation duct. Kind of like a self seal connector? Can you or anyone else help?
Good job , I do the same thing, use polyester fabric along with white duct sealant , but I seal on the out side when they have water leaks . Nice video , well explained ! Eric.
I replaced my AC unit and since then I have been coughing. I was told that I probably need to have the vents sealed..How and who does that? Can anyone tell me please...
@@520manhattan I'm no professional but you said you replaced them ...maybe while up there you didn't have the proper respirator to protect you from the fiberglass insulation ?? maybe your lungs are recovering from the installation alone and not the duct work
I have a square/rectangular return air duct in my attic and I believe that it's sucking attic dust/fiberglass insulation particles into our home and causing our allergies to become inflamed. It's around 15' - 20' in length and not something I feel comfortable pulling out to tape. The main reason why is I dread trying to refit it back to everything that it is attached to as it has a few intakes that it's attached to. The duct sits between two joists that run alongside it so I cannot get mastic or tape on the sides and bottom. Can I just cover the venting w/ plywood, attaching it from joist to joist so it stops sucking in fiberglass insulation particles and dust? I figure I could put some type of gasket sealer between the plywood and joists to prevent air from getting vacuumed in.
I got heat from the outside coming in to my bathroom exhaust fan and stovetop fan. Then I have to clean mold every 2 months mainly in the summers. How do you fix that?
hey you changed your hat by the end of the video ;) Thanks for the tips. I'm seeing 1/2 gallon for 20$ at Home Depot. Do you have any direct links to the products you used?
Hello Corey, is there anyway I can send you some pictures of my filter rack? One technician made 7 to 8 holes on the filter rack to adjust the straps that was holding it. And I was like, the air in the attic will go inside the filter rack now? And he put tapes on the holes to stop air leakages but to make things more secure he put lot of mastic duct sealant top of all the tapes that were covering the holes and some other holes without the tapes too. Some parts we couldn't put tapes because it was in some spots that was hard to reach. Anyways, he put lot of mastic duck sealant. Like almost everywhere inside the filter rack. He told me it's none toxic but it's been few days now and I am still afraid to turn on the heater at home and I have a little toddler as well. Could you please provide me with some clear answer. And if I could send picture that will be awesome too. Either way is fine. Thank you.
Hey Corey, my daughter bought a house that has all ductwork on the exterior of the roof. It is bare metal, the entire trunk line and return. Can you recommend the best way to stop the energy loss?
Great advise Corey. What's your thought's on a rigid PVC or ABS square ventilation duct, rather than metal ducting? The reason I ask is that this type of ventilation flat duct can be used with self seal connectors. So mastic doesn't need to be used to seal the joints.
can i use this mastic for my air conditioner duct vents located on top of my roof.. to use as a water sealant. I notice my vent joint were just taped up with aluminum tape and and covered with tar. please advise.
I don't have drywall tape so I HOPE just using the sealant works. I only have that silver type tape. But damn this is gonna a chore. Ty for the video. Only concern is drywall tape
I was cleaning out my attic yesterday day and horrible the sloppy work that the HVAC installer did from years ago. We purchased house less than 1 year ago. We are sealing all the holes from ducts, pipes and electrical. Also changing out the insulation.
I just acquired a 2 story building with an elderly woman on the first floor. I learned that her unit is heating the commons area in the hall/stairs. Code does not require them to be heated in our area. I would like to reliever her of this burden but don't know what to do. Any suggestions?
Hi I have a very old house I have this on going problem when it snowed n temp drop very cold the 1 story ( no attic ) living room ceiling would leak I just replace the roof last year Now I’m thinking maybe it the heat leaking from the vent and heating the roof, pls advise Large gaps between the ceiling register and the opening
My guess would be a lack of insulation on the ductwork. the warm air inside the duct will cause uninsulated duct to sweat. poke your head into your attic and see if there is insulation on your ductwork, in my juriisdiction code is 5 feet from any penetration as well as all ductwork inside unconditioned spaces (like an attic)
Can I put mastic on the flue pipe that goes into the chimney or should i use furnace cement for that area? I put some 3m 2,500 degree caulk and it has all flaked off.
Go to a sheet metal supplier and ask for plugs of the proper size. Dunno the best way to do it without seeing it, if you get spun plugs you could probably take the wallcap off and figure a way to cut the duct back and shove the plug inside the duct then screw from the inside out. You would need some siding material too or I guess you could just affix the old wallcaps again. Also, do you know what these ducts service? If you plug them, especially in the case of a dryer vent it could be very bad, duct full of lint at best, fire at worst. If it's a bath fan or range you will probably burn out the fan motor.
So I think I have a partially disconnected duct in an upstairs bedroom. My guess is they would need to tear through either the ceiling below or the subfloor in order to get to this? We have little or no ventilation in any of our upstairs rooms.
This year I air sealed and insulated all my ducts and pipes. What a difference! No longer heating my crawlspace and all of that warm air is pumping into the house where it belongs!
Nashua 327 is a mastic based tape which works well. I have always considered mastic sealed joints to be the "RIGHT" way to install/fix a duct system. For those who say the Nylon/fiberglass webbing is "Overkill", apparently do not understand adhesives/glues/epoxies. ANYTIME you can add the reinforcing webbing it does add great strength to the adhesive, making it more durable against everything, including vibrations, clumsy cable guys etc. You may not want to spend the time and effort to use the webbing, but in my book it gives the best job possible...HVAC 30+ yrs.
Well.... "Simple and easy" if the duct has been pulled nicely out of the wall and is in your hands. Excruciatingly difficult if you also have to find the leaks on ductwork inside of walls and/or layers of insulation, expose the ductwork, seal it then re-insulate or reinstall it inside the walls. Before everyone runs to the hardware store to buy mastic sealant, make sure you know where your main leakage points are and be assured that you can access them easily or you might night want to DIY this project.
That said, I DO know exactly where the leaks in my system are and found this video very helpful so THANK YOU!!
I encapsulated my crawl space last year. I just noticed the dryer vent connections down there were terrible. So this was a great overview of mastic. It should save me some on my AC when I get that sealed.
I just came across your channel as I was searching for mastic duct sealant. Great videos. I hope you start up your channel again. A lot of people in my neighborhood have been fixing up their homes since the start of the pandemic.
Look at you go Corey! Nice video. I've been in the sheet metal industry for more than 30 years and I can't preach enough about how important it is to seal duct work. I never thought to use the sheetrock tape, great idea. I wouldn't typically use it on the commercial jobs I work at because time is money but home projects for sure. I would also recommend using the sealer on the snap lock seam going length ways on the duct. Wiping off the duct is a must. Like I said. Nice video! Be safe! Phil D.
20 years ago I had my basement refinished. I added 5 vents down there and specified no duct tape in the project on the contract. Their HVAC sub said it didn’t matter the heat was still going into the home. For other ridiculousness I told them not to let him back on the job site.
It’s to bad when someone has done something for 30 years but will not learn something new.
Hey Corey, thanks for taking the time and effort to produce this easy to understand tutorial on the sealing of duct joints with mastic.
Thanks Corey for this great informational video. You can learn anything on RUclips because of creators like you. I have two vents that need attention, this video gave me the confidence to be able to do the job right.
I'll bet you have saved thousands of dollars in energy with you videos. Thank you so much!
We just had all metal ductwork put under our house in the crawlspace. Our HVAC contractor did not use mastic but instead used the foil faced HVAC tape to seal all joints and seams.
Now put duct insulation around it if you can easily access it.
Cool! That's definitely a permanent job, and will increase the efficiency of the ductwork. Thanks for posting, and keep up the good work!
Great clear video with all cost & time needed. I plan to seal all mine Ty. Cheers Jeff :)
Thanks for the very helpful video, I just purchased some mastic today and didn't know how to use it.
That's what I'm talking about! Thanks for the video, exactly what I needed!
Thanks Corey, 4 this short but effective lesson I'll do it my self in 1 air leak -duct in my house :)
Nice simple video - thanks for sharing this.
Thanks for the comments!
For years, HVAC installers have been using DUCT TAPE to air seal the joints in duct work. Strangely enough, duct tape is not made for working on ducts because the glue can not handle the heat.
Energy Star estimates most homeowners lose 20% of the money they spend to heat and cool their homes because of leaky ducts. The air disappears into the walls and attic spaces without reaching your living space.
This is a cheap way to save money and make your rooms comfortable.
How do you find the leaks if your wall is sealed?
@@genx8889 Look at thermal cameras like flir.
For even more years, they did not use anything at all to isolate the air duct)))
Plus duct tape is HIGHLY flammable!
Another good one, keep them coming.
Definitely worth the share for my readers! Thanks Corey
Great video! I'm going to run out and grab some mastic for this weekend's project.
Have you ever done any work around insulating fireplaces. I have a screen that seems to leak like a broken window. What insulation was there when the house was built seems to have fallen apart. Any ideas on what would be appropriate to use in that space?
Great simple video thanks a ton for sharing!!
Very good demonstration! And Corey is cute!
Thank you very much for making this helpful tutorial video.
I'm TOTALLY using tape now. thanks for showing.
Great help vid! Thanks for posting
thanks for sharing! Great video for sealing ductwork
I agree - using the drywall tape is a great idea!
Very helpful. Thank you.
Great info! Thanks so much!
Watching this in 2021, thank you so much for these 🥲🥲😅
Thank you so much. The video picture showed the paste I was trying to figure out
UL-181 tape works pretty good too, and way less mess/work.
Hi there, great Video. I'm in the process of starting to finish my basement. I have duct work in my floor joists for both upstairs and basement. The Permit I am acquiring tells me I should use Low Wall heating here in ON Canada, something like what is in in your video. Is that the best way, i.e. remove my existing duct work for my basement and run duct work in my studs for each room.and of course leave the duct work for the upstairs. Should the cold air intake be higher than the warm air. thanks
Thank you Corey!
Local HVAC tech quoted me $4500 saying my ducts needed replacing, but it's obvious they only need sealing costing a couple hundred bucks DIY and a few hours work. I was also quoted $4500 to have the blow sealing done. Yea, not happening. Thanks for the info.
U cheap bro
Idk anyone with these type of metal ducts exposed, but it's a bitch to do, if a company if going to reseal them, they might as well replace them if the sheet rock is coming down, they probably have mold in them anyway if they're old. There's a reason they don't want to just reseal them.
can you apply in winter when furnace is being used?
I'm putting together a wood shop dust collection system and realize the fasteners are intended to immobilize the pieces in relation to each other and that the main trunks are best assembled on the floor. How long will it take for the mastic to dry or cure thoroughly enough to be roughly handled without transferring where unintended?
Thanks foe the video, Bill
I have an old house with pipe and conduit penetrations through the duct work. Now sealed with what I think is asbeotos/tape. How do I reseal these penetrations after getting asbestos professionally removed? Fiberglass tape and mastic?
Great video!
Does this work closer to the furnace where the duct gets really hot??
Seal them up! Thanks Corey
hello I have a question after putting the mastic how long does it take to dry and turn on the air
For fiberglass duct from boards do I use mastic or just tape and be done.
Can I use fan right after the mastic was applied to box-duct connections in the attic?
Will this stuff be good for outside ac duct? When it rains, I have water coming in thru the vent
my mastic jobs that I have owned over the years looked like broken arm or legs casts. Smooth and rock hard all around the steel. Maybe the old school way of doing it so it looks good.
Must depend on jurisdiction. As far as i have discerned resi has less sealing than the POS condos I worked for the last 8 months. Resi tends to be piecework where I am which means poor workmanship from my experience.
Does the mastic comes prepared, ready to use? Can I use duck tape instead of fiber glass tape?
Great video Corry thank sir
Can I use that inside of a fiberglass duct? I don’t have access to the outside of the duct only the inside. Thank you
Would this also cause condensation around my vents?
I assume you can use mastic on both AC (cooling) ducts as well?
Thanks Corey. Great video! Some things just make sense and putting drywall tape on does just that. After all mastic is in putty form as you are putting it on just like drywall mud.
On my house, which was built in 2006, they used DUCT TAPE and then covered the DUCT TAPE with mastic. I wish they had used mastic by itself as the duct tape that is mastic covered is coming off and allowing massive amounts of air to leak out. I have fixed a few of the largest leaks and will fix the rest soon.
My installers used foil tape then mastic I was perplexed!
Should I just use mastic only? Or should I use premium foil tape then mastic. Or a thin layer of mastic, then tape and cover with mastic again? I'm trying to figure out what is best option and planning on doing this soon.
Question. My supply plenum became unseal in one long area , can I just add more mastic and fiber tape to seal it? How long do I let it sit before it is dry and can turn on the AC?
I can't find mastic at home depot or lowes. Is it only available through order
I love ducks. Especially in gumbo!
Thanks 🙏 a million you’re dope!
Nice tip!
Thank you!
Thank you Sir!!
Good stuff. Thanks!
could you use that mastic to cover asbestos duct tape?
Great video! I'm trying to find a solution that's cheap and leak free for my square ventilation duct. Kind of like a self seal connector? Can you or anyone else help?
Great Video
Can you put sealant over old tar sealant?
Good job , I do the same thing, use polyester fabric along with white duct sealant , but I seal on the out side when they have water leaks .
Nice video , well explained !
Eric.
I replaced my AC unit and since then I have been coughing. I was told that I probably need to have the vents sealed..How and who does that? Can anyone tell me please...
@@520manhattan I'm no professional but you said you replaced them ...maybe while up there you didn't have the proper respirator to protect you from the fiberglass insulation ?? maybe your lungs are recovering from the installation alone and not the duct work
Once the ducts are sealed , don't you need insulation on them?
I have a square/rectangular return air duct in my attic and I believe that it's sucking attic dust/fiberglass insulation particles into our home and causing our allergies to become inflamed. It's around 15' - 20' in length and not something I feel comfortable pulling out to tape. The main reason why is I dread trying to refit it back to everything that it is attached to as it has a few intakes that it's attached to.
The duct sits between two joists that run alongside it so I cannot get mastic or tape on the sides and bottom. Can I just cover the venting w/ plywood, attaching it from joist to joist so it stops sucking in fiberglass insulation particles and dust? I figure I could put some type of gasket sealer between the plywood and joists to prevent air from getting vacuumed in.
What temperatures does it support?
Is this better than the silver color tape?
Can I use this stuff for outside stucco on a 4x4 inch wide hole
What can I use for outside? I have duct on top of roof. I need a sealant to protect it from rain
can a rivet gun anchor the sheet medal to the duct work hole ?
Awesome thank you
I got heat from the outside coming in to my bathroom exhaust fan and stovetop fan. Then I have to clean mold every 2 months mainly in the summers. How do you fix that?
hey you changed your hat by the end of the video ;) Thanks for the tips. I'm seeing 1/2 gallon for 20$ at Home Depot. Do you have any direct links to the products you used?
Does it dry white?
How do it use it on already installed ducts?
I hope you did the long seams also before you covered it. If you didn’t air will be leaking there still. Those are not air tight when built!
Hello Corey, is there anyway I can send you some pictures of my filter rack? One technician made 7 to 8 holes on the filter rack to adjust the straps that was holding it. And I was like, the air in the attic will go inside the filter rack now? And he put tapes on the holes to stop air leakages but to make things more secure he put lot of mastic duct sealant top of all the tapes that were covering the holes and some other holes without the tapes too. Some parts we couldn't put tapes because it was in some spots that was hard to reach. Anyways, he put lot of mastic duck sealant. Like almost everywhere inside the filter rack. He told me it's none toxic but it's been few days now and I am still afraid to turn on the heater at home and I have a little toddler as well. Could you please provide me with some clear answer. And if I could send picture that will be awesome too. Either way is fine. Thank you.
cool video
Hey Corey, my daughter bought a house that has all ductwork on the exterior of the roof. It is bare metal, the entire trunk line and return. Can you recommend the best way to stop the energy loss?
Start from scratch.
Great advise Corey. What's your thought's on a rigid PVC or ABS square ventilation duct, rather than metal ducting?
The reason I ask is that this type of ventilation flat duct can be used with self seal connectors.
So mastic doesn't need to be used to seal the joints.
breaks building code. no fire rating on that shit. Also would be much more costly
Pvc offgass is around 90f
I know pvc in dust collection creates loads of static
can i use this mastic for my air conditioner duct vents located on top of my roof.. to use as a water sealant. I notice my vent joint were just taped up with aluminum tape and and covered with tar. please advise.
Yes
I just bought a mobile home and found the vent duct leak air under skirt . Thank you for the tip .
I don't have drywall tape so I HOPE just using the sealant works. I only have that silver type tape. But damn this is gonna a chore. Ty for the video. Only concern is drywall tape
I was cleaning out my attic yesterday day and horrible the sloppy work that the HVAC installer did from years ago. We purchased house less than 1 year ago. We are sealing all the holes from ducts, pipes and electrical. Also changing out the insulation.
Does mastic have an odor?
what colors?
Lol I heard the prices and did a double take!!! Lots changed in the last 12 years….. WOW
mastic! Thanks
I just acquired a 2 story building with an elderly woman on the first floor. I learned that her unit is heating the commons area in the hall/stairs. Code does not require them to be heated in our area. I would like to reliever her of this burden but don't know what to do. Any suggestions?
Block off the air with a damper from going to that area, what's the issue with just letting it blow?
Can you add hvac tape and mastic seal from the inside? These are for already-built homes
yup, just make sure that shit is smooth so that airflow is not affected. the tape is a bit overkill too, that mastic lasts longer than you or I will
I have a peel and stick product that would work great in this situation. How do I contact you to show you my product?
Did you ever get this done?
Hi I have a very old house
I have this on going problem when it snowed n temp drop very cold the 1 story ( no attic ) living room ceiling would leak
I just replace the roof last year
Now I’m thinking maybe it the heat leaking from the vent and heating the roof, pls advise
Large gaps between the ceiling register and the opening
My guess would be a lack of insulation on the ductwork. the warm air inside the duct will cause uninsulated duct to sweat. poke your head into your attic and see if there is insulation on your ductwork, in my juriisdiction code is 5 feet from any penetration as well as all ductwork inside unconditioned spaces (like an attic)
Can I put mastic on the flue pipe that goes into the chimney or should i
use furnace cement for that area? I put some 3m 2,500 degree caulk and
it has all flaked off.
Furnace cement, Tom Dee. Nothing else.
Don't fuck around with chimneys unless you want to die. Call a pro
How long do you have to let the mastic dry before turning the AC or heater back on?
I know it's late answer and not from the channel person but it's 24-72 hrs
ok great job
I want to close off 2 round about 5 to 6" ducts on the patio, have a way I can do this without having someone come out?
Go to a sheet metal supplier and ask for plugs of the proper size. Dunno the best way to do it without seeing it, if you get spun plugs you could probably take the wallcap off and figure a way to cut the duct back and shove the plug inside the duct then screw from the inside out. You would need some siding material too or I guess you could just affix the old wallcaps again.
Also, do you know what these ducts service? If you plug them, especially in the case of a dryer vent it could be very bad, duct full of lint at best, fire at worst. If it's a bath fan or range you will probably burn out the fan motor.
So I think I have a partially disconnected duct in an upstairs bedroom. My guess is they would need to tear through either the ceiling below or the subfloor in order to get to this? We have little or no ventilation in any of our upstairs rooms.