Last updated on June 1, 2022 9:10 pm by the writer.
How does Flex tape work?
Flex Tape otherwise known as flashing tape is a popular adhesive tape that’s known for weather protection and strength for various waterproofing around windows and under cladding systems as a backup waterproofing protection system.
A step above and beyond even duct tape, the thick, rubberized backing of Flex Tape is highly malleable and ideal for bonding and sealing surfaces around flashings, and holes in building paper, although the tape is used in other DIY situations.
It’s also ideal for waterproofing high-risk areas in a building that could leak underneath a primary cladding system,
In the event of a building element failure, this tape can be a backup to keep water from entering and rotting timber frames around doors and windows.
Flex Tape’s special secret polymer coating makes this even more sticky than chewing gum in your hair.
Most types are found to be UV-resistant, and waterproof, allowing the tape to withstand extreme temperatures and adverse weather conditions and improved adhesion over time from heat.
This tape literally ‘flexes’ in the face of standard cello tape.
Uses of Flex tape
Seal and patch holes
In certain scenarios where pipes and other constructs need to penetrate out of an external wall, the gaps in the hole can be taped up underneath a wall cladding with flashing tape.
Flex Tape does the job without needing to weld, use putty, and the like.
The properties of Flex Tape make this sticky stuff waterproof as a secondary layer of water protection method under a cladding material, meaning that tape can be used instead of a more expensive tube of sealant.
Some people even use flex tape for the corners of aquariums, pools, and even sinks!
Block window leaks
Fine cracks on window edges or small holes on windows will be no problem for Flex Tape.
Use the tape as a temporary way to prevent leaks without having to dismantle or have your windows serviced straight away.
Block air leaks
Fine cracks on window edges or small holes on windows will be no problem for Flex Tape.
Use this solution to prevent a breeze from entering your home through a hole or having to dismantle parts of your building.
Why is this tape so hard to remove?
Sometimes you put the tape on but the window opening needs to be made bigger therefore the sill tape needs to be removed.
Other times you might need to remove the tape is when this hack was only used as a temporary fix for an emergency repair.
As the adhesive behind FlexTape is something remarkable.
The seal in the tape acts pretty much like silicone, except that the bond gets stronger over time as opposed to electrical tapes that tend to lose their “stickiness” relatively quickly.
So, can you remove Flex tape?
Flex Tape can most definitely be removed but this is not easy.
Start by pulling away at the tape bit by bit, removal is easier when newly applied, the longer you leave the seal with subject to time and heat the more sticky the backing and the join becomes.
However, for tape that’s been in place for quite some time, you might need the help of an adhesive solvent (remover) or an acid-based degreaser.
Methods to remove flex seal tape
Flashing tape requires a little extra effort to remove as opposed to standard tapes – an understatement.
Although removal can be done with time and effort, however, for those who don’t have the means to get an adhesive remover.
So if you’re wondering – “how do you remove flex tape”, try out the following methods below.
1. By hand
You can always go with the tried and tested method of peeling and scraping.
Pull away at the tape just enough to lift the corners up, then use either your hands with gloves or a pair of pliers to try and pry it away bit by bit or to help grab the edges as you apply a remover or degreaser.
Alternatively, you can also scrape the backing off using a large knife like a machete blade. This is the most basic and used method.
2. How to use flex tape adhesive remover
- Lift up at least the edge of the tape. This’ll create an opening.
- Firmly grip the tip of the loosened tape and pull as much as you can.
- With your free hand, grab the Flex Tape Adhesive Remover and point the nozzle at the gap between the tape and the surface and start spraying.
- Continue pulling on the tape as you spray the remover.
- Continue to spray-controlled amounts until the tape has fully come off.
- Wipe any excess remover.
3. Using a circular saw
If the tape is stuck on like super glue and you need to make a window opening a little larger, you can just cut a new line just under the tape with your circular saw removing a small sliver of wood, and having a clean surface of bare wood again.
This can be better done by cutting the jack studs with a reciprocating saw and removing the sill and reinstalling the timber sill plate down lower, with the tape still attached.
Line up the saw just slightly below the surface of the tape. You might need to redo the new surface to be smooth. Do this by running an electric or cordless plane over the sill.
Be careful not to remove too much of the sill framing and to not damage the integrity required to hold the weight of the window.
When sitting in the window you should use packers directly over top of the jack and trimmer studs to transfer the weight directly to the vertical supports, not the sill.
How to remove sticky flex tape backing left behind wood?
1. By chisel/ scraper
- Try to remove as much of the tape with the backing still on by hand first.
- After peeling as much off as you can use a large chisel, or a scraper to remove as much of the tar-like backing as you can be left behind.
By reciprocating saw
If that tape is sticky and not easily coming off with the backing still stuck on. You can use a reciprocating saw to cut downwards under the tape, trying not to notch the framing too much.
This will be messy but might speed up the process of removal using a bi-metal blade.
- Line a reciprocating saw slightly downwards towards the tape, using an old blade.
- Since this is a soft and rubbery material, set your speed setting to low and spray some water as you cut to keep the blade lubricated to stop the tape from melting and sticking even more.
- Slowly move the saw along the same way you would cut wood. Follow the line under the tape and the framing.
Tools to avoid
Watch out for certain tools when removing sill tape that could cause even more problems.
Tools that prove to be incompatible for Flex Tape removal are tools that could cause danger to you or could put a great tool into the need of a serious repair if the tape gets into the motor, or inside any moving parts.
Respect your tools, getting a reciprocating saw blade dirty is one thing but for other tools, you should keep them away from sticky stuff.
An electric planer
Any planer, especially an electric one, If a planer goes over wood with partial bits of flex tape in the way, the fragments will clog up the mechanisms in the mechanics of the blade.
The tool is only designed to take off small amounts of material (I.E shavings).
But with flexible sticky tape you can end up shredding the tape and while an electric planer can remove it, the damage will now be inside your tool, clogging up the motor, resulting in the need for internal repair and pre-mature changing of the blades.
A heat gun
Especially in scenarios where you need to remove the backing, using a heat gun will melt the tape and can make the tape even more sticky.
A heat gun can ruin everything if you want to remove the sill tape in a clean way.
How to remove Flex tape from hot water pipes?
Flex Tape’s special composition allows the roll to be applied to both hot and cold pipes. Even though we don’t recommend the use of tape like this.
As tape on hot pipes can melt from the heat, and cannot hold back a strong water pressure safely or effectively anyway.
Removing flex seal tape from a hot water pipe is similar to how you would remove the layer from a standard, non-thermal-application pipe (I.E steel pipe).
First, if possible, shut off the heat source, this allows for much safer and easier removal.
Next is to grab some pliers and simply lift up and pull on the tape.
Since the pipe is round, adhesion should be relatively weaker the tape should come off more easily than from a porous material like wood or building paper.
But you have to ask yourself why flex tape is on your water pipe in the first place.
The tape won’t safely hold against water pressure, and if you are drinking from the water the health of the water becomes questionable.
Copper pipes need to be brazed to fix any leaks or to make a new pipe join.
How to remove flex tape from metal?
Removing the tape itself is not too hard to remove from metal compared to wood.
Simply peel that clingy stuff off to remove the tape as you would any other regular type of tape. Use some pliers if you find the edges hard to get a hold of.
Once the tape is removed, you can clean off the residue by using a chemical remover/ cleaner or a rag with some hot water and acetone.
How to remove Flex tape from an acrylic tub?
Removing Flex Tape from an acrylic tub is similar to removing the band from pipes. Simply peel off the tape from the edges and proceed to pull it until it comes all the way off.
Alternatively, you can also make use of a chisel, don’t worry about scratching the acrylic if it’s not visual, it’ll simply take a few small scratches.
Any left residue you can wipe off with a rag dipped in warm water and dishwashing soap or a chemical remover.
How to remove Flex tape from window trim?
Though you can do this by hand, you might find this troublesome.
Grab a pair of pliers, a small knife, and a chisel or a scraper.
Cut off any excess tape beyond the borders of the trim.
Scrape loose the remaining tape and use gloves to grab and pull it off.
Likewise, you can also use a chisel to slowly scrape at the tape until the tar comes off.
How to remove Flex tape stains?
We’re all familiar with that sticky gunk that tape leaves behind when removed, especially if the tape was attached for a long time.
Over time, the adhesive from the tape forms a harder residue as the black tar-type backing sticks.
This is a regular nuance for most tapes, when the residue is left behind from Flex Tape is like regular tape but much worse.
Though similar, residue will be a lot more persistent. Use the above chemical methods to get rid of that annoying black stain!
1. From concrete
Take your finger and dab a small amount that is just enough to cover the residue.
Let the oil soak for about 7 minutes and then wipe clean.
If this doesn’t work you can use fine-grit sandpaper on our favorite cordless orbital hand sander to sand the stain directly right off.
2. From wood
Take a putty knife and gently scrape against the surface of the wood with a chemical dissolver.
Otherwise, you can also sand the stain off with an electric sander.
3. From vinyl
You can simply use warm water here.
Dampen the surface of the vinyl then scrubs the residue off with either a rag or cloth so as not to scratch the surface.
Use slow back and forth strokes.
4. From carpets
To fully remove residue from carpets, they’ll need a thorough wash. For visible residue, scrape or pluck as much off by hand as possible.
Next, we suggest steam-cleaning or scrubbing your carpet with soap and warm water. Alternatively, you can also use chemical carpet removers.
6. From ceramics/ tiles
Tape residue on your beloved tile flooring can easily be removed using the ever-so-popular water + baking soda solution.
Apply the paste over the residue and gently scrub until clean. For older and more persistent stains, substitute acetone or nail polish remover for the baking soda.
7. From fabrics
When life comes to doing the laundry and having flex tape stuck to your workwear. You want to remove any visible stains.
But sometimes builders use the tape to fix rips in pants!
First, submerge your piece of clothing. Gently scrub with some dishwashing liquid then let your t-shirt sit for about 20 minutes in warm water.
Let the fabric air-dry and viola! Good as new we hope!
8. From car bodies
With a non-abrasive cloth, like microfiber, or a sponge, dab a little bit of acetone or nail polish remover on the residue.
And simply wipe or scrape the residue away once soft and loose enough.
Doing this should fully remove any residue without damaging the paint job.
Dos and don’ts when removing flex tape
- Do position yourself in a way that makes life easier when you pull safely.
- Do get the adhesive remover if you can.
- Do make sure that there aren’t things you might knock over when removing.
- Don’t pull from the bottom when removing the vertically-placed tape.
- Don’t use unfamiliar removers or unsupported/non-factual alternatives.
- Don’t remove the tape by force if it’s too well bonded. Take your time and use removers if necessary.
How to remove the backing from Flex seal tape?
- Lift up the tip of the backing by prying at one of the tape’s edges. Use either a fingernail or a sharp edge.
- You should see a small separation between the backing and the tape itself.
- Just peel the backing as you install the tape.
Flex Tape is one of the toughest tapes around.
For all that this sticky stuff can do, the problematic concern with Flex Tape is not how and where to use it, but how to remove the stuff if you put the flashing tape in the wrong spot.
While this type of tape can do wonders as a means of emergency repair and patchwork, removing the tape might prove to be more trouble than it’s worth. Ask yourself can just stay there?
Luckily though, we’ve covered most of the best ways to remove flashing tape without too much worry.
This guide will surely come in handy if you ever get stuck. The next step is to know how to re-glaze a window.
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My name is Aaron, and thank you for reading my article. As a qualified builder, I share some tips here at Bangingtoolbox to help provide accurate DIY information on the internet.
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