What’s The Best Sealant for UPVC Windows in 2021?

Are you looking for the best sealant for UPVC windows?

Surely, you have hit the jackpot today! We know how difficult it is to find a sealant that stays durable under extreme weather conditions and does not fade because of the scorching heat.

Moreover, the major mistake people make while looking for a sealant is that they expect to find the one that works on everything. In reality, there is no such sealant that does it all. Hence, you need to read our product reviews and detailed buyer’s guide to choose the one which suits you best.

Best Sealant for UPVC Windows

We have handpicked the best of the lot for you! So, relax!

All the sealants reviewed are durable, quick curing, flexible and give maximum coverage.

10 Best Sealant for UPVC Windows – Pick Out of the Best Today

With so many options in the market, you must be thinking:

How do I know which one is best? Don’t fret! We’ve got your back.

I have tested and shortlisted 10 sealants which are the best sealant for UPVC Windows.

Hence, just read on and decide which one you will buy.

Truly PVC Supplies 4 SealantBlackSilicone Check Price
Truly PVC Supplies 4 SealantAnthracite GreySilicone Check Price
Claddtech Silicone Sealant PanelWhiteSilicone Check Price
UniBond RE-NEW White SealantWhiteSilicone Check Price
Gorilla Clear 100% Silicone SealantClearSilicone Check Price
GE GE5000 Advanced SiliconeClearSilicone Check Price
Permatex 80050 Clear RTV SiliconeClearSilicone Check Price
Loctite Clear Silicone WaterproofClearSilicone Check Price
Permatex 81158 Black SiliconeBlackSilicone Check Price
Surebond High-Temp Silicone SealantBlackSilicone Check Price

1. Truly PVC Supplies 4 x White WP70 Silicone Sealant – Best Choice for UPVC Windows

Truly PVC Supplies 4 x White WP70 Silicone Sealant

Let me introduce you to one of the best sealants for metal, wood, plastic, and even stone!

Yes, stone… you read it right: As it is versatile and can be used on different surfaces around the house. Therefore, you do not need to worry about buying multiple products for different surfaces.

Undoubtedly, it gives a very professional look. Moreover, the quality of WP70 is outstanding and the extra UPVC adhesion makes it the first choice for both, builders and homes DIY enthusiasts. Moreover, you get a pack of 4.

Are you planning to apply the sealant outside? This has you covered. This RTV sealant can withstand extreme weather and temperatures. It can take on saltwater immersion, ozone and is unaffected by UV.

Unlike others, this silicone sealant will maintain its stability and elasticity at both low and high temperatures.

Furthermore, its resistance to other chemicals makes it a fail-proof option when you are working professionally and can’t afford any mistakes.

Moreover, the color does not fade either. It will remain black and no amount of rain, erosion, and sunlight will make its color fade. Moreover, it picks up less dirt and gives a better finish as compared to the rest of the sealants on the market.

Do you have the patience required? Well, one thing to keep in mind is that this is a neutral cure sealant.

Haven’t you read that before? Don’t worry. I got your back!

Simply put, it takes time to cure or dry. So, you need to be patient with it.

Heard the saying “good things take time”? Similar is the case with it. For the best, professional results, you need to give it time to dry.

The most amazing thing is that the odor is nothing as compared to similar products. I have used sealants that give off such a strong odor that you can’t stand it entirely.

But it was such a pleasant surprise that the odor on this is less. You can hardly smell anything.

The flexibility makes it water-resistant. Hence, no worrying about the water coming in during heavy rain. Therefore, it does not cause any damage.

I know what you must be thinking, “Can it be dangerous”? Certainly not. It is a certified low MEKO and does not cause any damage to your health.

And the best part is: That meets international quality standards.

Yes. It is ISO 11600-F&G-25LM certified.

Finally, something we can rely upon! But wait, let me tell you that it is not suitable for use on natural stone, self-cleaning glass, aquariums, fish tanks, bitumen, and asphalt.

Moreover, do not overuse it by painting multiple layers.

  • Weather-resistant.
  • Low MEKO.
  • Rapid curing properties.
  • Economical.
  • Long-lasting.
  • Easy to use.
  • Cracks appear, if not applied properly.

2. Truly PVC Supplies 4 x WP70 Silicone Sealant Low Modulus Builders – Best External Sealant

Truly PVC Supplies 4 x WP70 Silicone Sealant Low Modulus Builders

Wait, are you unable to find the perfect sealant for your grey window frames? No need to look around anymore, you have just struck it lucky.

This WP70 Anthracite grey sealant is exactly the thing for you. Not only is it of very high-quality, but it also conforms to the ISO 11600-F&G-25LM quality standards.

Isn’t that a pleasant surprise? To add to it, the low MEKO value makes it comparatively better than the other products on the market.

It is one of the most durable sealants out there.

How can I claim that? Well, it is weather-resistant like the rest of them. But, unlike the rest, it has no oils or fungicides that let water seep in. Hence, making it both durable and water-resistant.

Therefore, no amount of rain, snow, or water can make it budge, crack, or come off.

Moreover, the RTV adhesive in it can withstand extreme temperatures. Not only that, but it is not affected by the ozone or UV rays.

The fact that it is weather and water-resistant does not let the color fade off. Because of this, it is the first choice for builders.

What else can one ask for? Not much, right? But the features just keep on multiplying.

It comes with additional PVCU adhesion promoters. Secondly, it is flexible. Thus, making it an excellent choice for external use.

For instance, it can be used for door and window frame sealing, glazing work, flexible jointing, and on the whole as a builder’s sealant.

Another feature that makes it stand out is the versatility: It can be used for almost anything. For example, plastic, wood, metal, stone.

You name it, WP70 will seal it: The only limitation is that it cannot be used in fish tanks, aquariums, natural stone, asphalt, bitumen, and self-cleaning glass.

Apart from these, it works on things like magic.

Slow and steady wins the race: After application, you need to be patient with it. It needs time to cure. Even though it has rapid curing with good adhesive properties, it still needs time.

So, don’t rush. For a professional result, you need to give it time to dry. The most amazing thing is that the odor is nothing as compared to similar products. I have used sealants that give off such a strong odor that you can’t stand it at all.

But it was a surprise that the odor on this is less. You can hardly smell anything.

Just keep in mind not to apply multiple coats. Always apply as much as required and don’t overdo it. As it results in cracks and the material chipping off.

Oh wait, you do not get only 1 but get a pack of 4.

  • Conforms to ISO standards.
  • Economical.
  • Long-lasting.
  • Low-MEKO.
  • Low odor.
  • Best for external use.
  • Cracks if multiple coats are applied.

3. Claddtech Silicone Sealant Panel Adhesive-Bonding – Best to Be Used in The Kitchen

Claddtech Silicone Sealant Panel Adhesive Bonding

Are you in search of the best adhesive specifically for your bathroom and tough areas like the kitchen? This multi-purpose silicone sealant is not only the best option to use in your bathroom but can also be used around the house.

So, how can I claim that it is the best for bathrooms? Well, it has been designed specifically for them. The non-porous nature does not let any sort of liquid or even air penetrate the adhesive. Consequently, it is perfect for places that have moisture and water, i.e. the bathroom.

Moreover, the fact that it is mold-free and waterproof again makes it a perfect choice for bathrooms. Hence, it will not crack or fade away because of the moisture or water droplets.

Furthermore, it works perfectly on glossed surfaces also. Like bathtubs and tiles.

What else can it work on? Not only is it used for adhesive purposes, but it is also used to bond panels to other sound surfaces.

Thus, you can see how strong a sealant/adhesive it is. Moreover, it can adhere to the following surfaces:

Thresholds, Ornamental framework, plaster, concrete, chipboard, wood, polystyrene foam, skirting boards both UPVC and wood, ceramic tiles, masonry, plaster, and polystyrene tiles.

Phew, that is some list! One tube can neatly cover 4 panels of 270mm*250mm*5mm. That is quite a lot.

Moreover, one cartridge can bond 4 Claddtech panels which are larger than the normal panels offered.

All these features make it an ideal choice for residential and commercial buildings.

How long does it take to set? It sets pretty quickly. This is both good and bad.

How? Well, it means you need to get it perfect the first time. You do not have the cushion of correcting the application as once it sets, it can’t be undone.

The only downside is that you get 1 tube. So, you need to calculate exactly how much you will be needing before ordering as it seldom happens that all your work is done with one tube. So, buy wisely.

Nevertheless, it is very economical. Hence, can be ordered in bulk.

Variety is always welcomed: Undoubtedly, variety is always a plus point. Similarly, it is also available in 3 standard colors black, clear, and white.

So, pick the one that you need and get down to work!

Worried how will you clean it? It is very easy to clean and is hygienic. Moreover, it blends in so well you can hardly tell where it had been used after a few days.

  • Economical.
  • Excellent for use in the bathroom.
  • Nonporous.
  • Multipurpose.
  • 100% waterproof.
  • Easy to clean.
  • Strong fumes emit when you apply it.

4. UniBond RE-NEW, White Silicone Sealant – Ideal for the Bathroom

UniBond RE-NEW White Silicone Sealant

Want something to bring life to your lifeless kitchen or bathtub? As the name suggests, you can easily RENEW your kitchen and bathroom by applying this sealant.

First thing first: There is no headache of removing the old sealant. Yes, I am right.

It has never been easier to RENEW! Save yourself those long, tedious hours in scraping off the old sealant to make room for new.

All you need to do is clean the existing sealant with a lightly damp cloth. Now, open the cap and apply it on top, and…. You are done.

The innovative filler has a unique applicator that directly applies the sealant in all nooks and corners. Furthermore, it gets to those parts where the rest can’t get.

To apply it, hold it at a 45-degree angle and give it a little squeeze. Then, repeat the process for a perfect touch.

Furthermore, to minimize the risk of bubbles appearing, shake the bottle well in the downward direction before each squeeze.

It will dry in a jiffy! 6 hours is all it takes to dry.

Are you not satisfied with the application? Don’t worry.

Immediately remove it with the help of a damp cloth. Now, you can go over it again and apply a fresh coat.

Undoubtedly you must be worried about finishing: Certainly, the first thing that crossed my mind also was whether it will give a smooth and glossy finish or not. As the company claimed it can be applied over the old one. But the finish was as smooth as can be.

The reason being, the integrating smoothing tool delivers a perfect finish.

Surely, you must have heard about sealants being mold resistant: This comes with triple-mold protection. Not only does it prevent mold, but it also repels and kills it. So, if there is a mold that comes in contact with it, even then there will be no effect on it.

Wondering how much coverage this beauty gives? 1 bottle easily covers the entire bathroom. It covers 1 sink, 1 bathtub, and 1 shower. On the whole, it covers 5-7 meters.

It does have a few limitations. Firstly, use it with caution. Make sure it does not come in contact with your eyes. Secondly, the remaining sealant should be used within a month or discarded.

A very important thing to keep in mind: Never use it in permanently wet areas. It will not hold in there.

  • It gives a handsome coverage.
  • Easy to apply.
  • Dries quickly.
  • Triple mold resistance protection.
  • It can be applied to the existing sealant.
  • Easy applicator.
  • Cap comes off it squeezed tightly.

5. Gorilla Clear 100 Percent Silicone Sealant – The Most Versatile Sealant

Gorilla Clear 100 Percent Silicone Sealant


Ever heard of a sealant that can cover it all? Let me introduce you to the most versatile sealant out there: Gorilla Clear.

It is the best option available for sealing cracks and gaps between any two surfaces be it indoor or outdoor.

Surely, I was surprised as the sealants I have come across are either for use indoors or outdoors. Rarely do you find one which can be used in both situations? Hence, this was a pleasant surprise.

Moreover, after using it, it dawned upon me that this is surely something different.

So, read on to find out more: Surely, versatility is the name of the game.

You will have to look around and find a surface on which this does not work. It works on windows, kitchen, auto, marine plumbing, and even gutters.

Yup, it can even seal that gutter!

Can it get any tougher? A plus point is a translucent color. There is no headache of matching the color of the sealant and surface. Once dried, it becomes transparent and you need to look closely to see if it’s even present. Furthermore, it dries very quickly.

30 minutes is all it needs to dry. After that, you can use the surface without any tension and expose it to water.

The Gorilla sealant won’t lose its touch over time: The reason being, it is 100% waterproof and weather resistant.

Furthermore, mildew and mold resistance make it ideal for use outdoors. Thus, it does not yellow over time as no amount of water, sunshine, dew, mold has any effect on it. Moreover, it does not even crack or show any signs of wear and tear.

A thought that crossed my mind was that a sealant so versatile must have a detailed application process.

Surely, I was wrong: The application process is as simple as a breeze. Secondly, it gives you so much authority. For instance, it is up to you to cut the tip according to your desire.

Most people complain that their sealants are too thick or thin during application. To overcome this problem, Gorilla has given the user the autonomy to cut the bead size according to their desire. Now, you apply it with a caulking gun.

Speed things up: As it dries very quickly, you need to speed things up. Smooth the surface as soon as you apply the sealant. Because, if you don’t do that, you will not get a smooth finish.

A point to remember: For best results, use it in temperatures above 40F.

Caution: Keep away from eyes and try not to touch it with your bare skin as it can irritate.

  • Versatile.
  • Tough.
  • Mildew and mold resistance.
  • 100% waterproof.
  • Economical.
  • Is not paintable.
Gorilla Waterproof Caulk & Seal 100% Silicone Sealant, 10oz...
  • INDOOR/OUTDOOR: All Weather

6. GE GE5000 Advanced Silicone – Ideal for External UPVC Windows and Doors

GE GE5000 Advanced Silicone


Are you looking for something to withstand the severe day-to-day weather conditions? Of course, every house has areas that are constantly exposed to extreme weather conditions. So, for difficult areas like these, GE GE5000 Advanced Silicone is the name of the game.

Moreover, you can use it anywhere. Be it the attic, basement, windows, doors, trims, moldings, pipes, and wires, etc.

Yes, it can seal those pipes even! Not only is it 100% weather and waterproof, but it also provides a reliable seal in areas that are consistently subject to weather changes.

Hence, no amount of UV rays or rainfall will cause damage.

But, don’t all sealants do that? Yes, they do, But, it has 40% more flexibility as compared to the others in the market especially Class 25 sealants. As a result, it can also tolerate scorching heat and freezing weather.

Hence, it can tolerate major contraction and expansion without cracking or chipping off, neither will it shrink. Thus, it is a step ahead of the others.

Furthermore, you get 5 times more adhesion with it. Consequently, it makes it 5 times stronger than the rest.

Therefore, the durability quotient on it is very high: You can get an idea about the durability of its guarantee also. It is backed by a lifetime guarantee. So, you know how durable it is that the company guarantees it lasts you a lifetime. Hence, if you are unhappy with the product and have the original receipt on you, you can get an exchange anytime.

Moreover, it fights and repels mold for 10 strong years. Yes, it has a 10-year mold-free guarantee on it. Because of this, no mold grows on the sealant and it does not get wasted.

Are you tired of sealants that blemish surfaces? Certainly, that is an issue most people face. This neutral curing sealant does not cause harm to the metals it is used or does not leave any blemishes.

Nevertheless, it is always advisable to test it on a small area first to be safe from any issues.

How soon can it be exposed to water? I know this thought must have crossed your mind. It can be exposed to water as soon as 30 minutes- 8 hours depending on the circumstances.

If the bead size is 3/16”, humidity minimum 50% and the temperature is 65-degree Fahrenheit, your sealant will be ready for exposure to rain in almost 30 minutes.

On the other hand, if these conditions aren’t present, don’t expose it to water for at least 8 hours.

It cannot be painted and should not be used in aquariums or underwater.

  • Lifetime guarantee.
  • Ready for exposure to rain in 30 minutes.
  • It does not cause metals to blemish.
  • It does not shrink or crack.
  • 40% more flexibility than average.
  • Can become hard under certain conditions.
GE Sealants & Adhesives GE5000 Advanced Silicone 2 Window & Door...
  • 100% Waterproof and Weatherproof: 100% silicone formula offers...
  • 10-Year Mold-Free Product Protection: Cured sealant is resistant to...
  • Permanently Flexible with Strong Adhesion: Sealant offers 40% more...

7. Permatex 80050 Clear RTV Silicone – First Choice of the Automotive Industry

Permatex 80050 Clear RTV Silicone


Have you been searching for a sealant specifically for your vehicles? Permatex is just the thing for you.

Whether you are working on a home project, or need something to help you professionally in the automotive industry, relying on Permatex is what you need.

Why specifically Permatex? Well, the brand has market-specific formulas for heavy-duty industries like a motorcycle, automotive, off-highway, marine, etc.

In a nutshell, it works on the big shots! Not only this, but it is also used for general purposes, both indoors and outdoors. For instance, it can seal plastic, vinyl tops, weatherstripping, vinyl, fabric, metal, glass, etc.

Hence, it is very versatile. Moreover, it can be used on both vertical and horizontal surfaces without any tension.

I have always heard that sealants seal. This is the first I have come across that can not only be used to seal but repairs, mends, bonds, and secures the material also.

Therefore, it is multi-purpose also.

Being weather-resistant adds that wow factor! Now, you do not need to think twice before using it. The temperature range it can withstand is -75-degree F – 400-Degree F. Clearly, the weather does not affect it.

Undoubtedly, along with water and weather, the automotive industry has to deal with vibration. The vibration quotient on cars, trucks, etc. is very high.

A lot of consideration has gone into developing it. Hence, not only is it weather and water-resistant, but it also shows great resistance to vibration.

Extreme care should be exercised in applying it to the desired places. The chemicals can irritate the skin and eyes. Hence, if direct contact occurs, wash it off immediately.

There are some limitations to its use: Never use it for windscreen installation. Apart from this, it can’t be used for engine gasket or electrical connection applications. Always go for something specific and something that meets the required security standards.

No need to worry about finding an applicator as it comes with one. All you need to do is to break the seal and fix the nozzle.

Bingo! You are ready to go. It dries off quickly. Hence, you do not need to spend hours waiting.

Got a little extra on your surface? Not to worry at all. Just get anything sharp like a pocketknife and scrape off the excess. Will come off in a second and leave the rest smooth.

Initially, you get a strong odor while applying but it dissipates in a few seconds after exposure to air.

  • Dries quickly.
  • Strong.
  • Multipurpose.
  • Best for heavy-duty use.
  • Clear.
  • Economical.
  • The bottom bursts open if a little pressure is applied.
Permatex 80050 Clear RTV Silicone Adhesive Sealant, 3 oz
  • Professional Formula - This Clear Silicone Adhesive Sealant is a...
  • Do It All- Seal, Bond, Repair, Mend And Secure Glass, Metal, Plastics,...
  • Resist The Elements- Permatex Clear Silicone Adhesive Sealant Is...

8. Loctite Clear Silicone Waterproof Sealant – Best for Aquariums

Loctite Clear Silicone Waterproof Sealant


Finally, I have found the best sealant to use underwater. I was tired of looking around for something to use in my aquarium.

TA-DA! I stumbled upon the Loctite clear sealant. A Magical sealant that works so well on the water that it will amaze you. Not only the aquarium, it can be used on sinks, plumbing, tubs, and other household items also.

Of course, you can use it around the house inside and outside also.

Where else can it be applied? Without a doubt, it can be applied anywhere.

Hold your horses! The sealant has been uniquely manufactured to be used on a variety of different surfaces. For instance, it can bond some form of rubber, plastics, porcelain, stainless steel, aluminum, fiberglass, vinyl tile, granite, glass, ABS, and wood.

Furthermore, it can be used for repairing or sealing vents, toys, door frames, gaskets, appliances, the outer side of the fireplace doors, shoes and boots, etc.

Yup, even something as simple as your shoes! Surely, the list is not only long but incredibly unique.

Certainly, I know what you are thinking: “How is this possible”? You must be thinking about how it is so multipurpose. Generally, the sealants are specifically used for something. But, the uses on this one are manifold.

All of this is possible because of its many features which I will discuss below.

First, it is resistant to extreme temperatures from -35degree F to 140-degree F. This makes it an excellent choice to be used outdoors in the scorching heat or freezing winds.

On the other hand, being waterproof ensures durability in places that are prone to excessive exposure to water. Thus, making it perfect to be used in freshwater or saltwater aquariums.

But, here also it needs to be kept in mind that after a specific size, it does not hold. It is not suitable for aquariums larger than 114L or holding more than 18” of water.

Afraid the sealant will break on impact? Not to worry. It is impact-resistant and does not break or come off when something falls.

Hence, it is imperative to check all measurements before applying the sealant. It cannot be used on different types of plastics, marble, oil-based caulking, magnesium, iron, brass, concrete, zinc, etc.

Last but not least: It does not budge, crack, peel, or shrink. So, once you apply it forget about it.

Caution: Prolonged contact with uncured sealant can irritate your eyes and skin. Moreover, it can also cause respiratory issues. Hence, once you apply it, leave the place and wait for it to dry.

  • Can be used underwater.
  • Extremely strong.
  • Waterproof.
  • Multipurpose.
  • Resistant to extreme temperatures.
  • Strong smell.
Henkel 908570 2.7 oz Tub Clear Silicone Waterproof Sealant,...
  • Use for sealing or repairing door frames, windows, vents, toys,...
  • Bonds ABS, glass, ceramic, porcelain, wood, aluminum, stainless steel,...
  • Aquarium safe

9. Permatex 81158 Black Silicone Adhesive – Best for Electrical Wiring

Permatex 81158 Black Silicone Adhesive


I know how difficult it is to find something that goes well with sealing and repairing electrical wiring around the house.

So, to make things easier for you, I present the Permatex 8115 Black Silicone Adhesive.

Versatility is synonymous with Permatex: Not only can it be used on electrical wirings it can be used indoors and outdoors. For instance, it can seal plastic, vinyl tops, weatherstripping, vinyl, fabric, metal, glass, etc.

Moreover, it can be used on door frames, plastics, vinyl, fabric, seams, roofs, and weather-stripping.

Furthermore, it can be used on both vertical and horizontal surfaces without any tension.

I have always heard that sealants seal. This is the first I have come across that can not only be used to seal but repairs, mends, bonds and secures the material also.

The multipurpose nature is all because it is the weather, water, oil, grease, and vibration resistance.

Undoubtedly, a sealant that is resistant to so many things can be used on multiple surfaces.

How much can it withstand? The durability and reliability of a sealant can be measured by the temperatures it can bear. Permatex can withstand extreme temperatures from -75degree F – 450degree F.

OH MY GOD! That is A LOT! Clearly, under normal circumstances, it can never get as cold or as hot as this. Hence, it is durable and reliable.

No need to worry about finding an applicator as it comes with one. All you need to do is to break the seal and fix the nozzle.

There you go! It dries off quickly. Hence, you do not need to spend hours waiting for it to dry.

Oops! Dropped a little extra on your surface? Not to worry at all.

As it dries quickly, getting the extra off can be worrisome. But, not in this case. Just get anything sharp like a pocketknife and scrape off the excess. Will come off in a second and leave the rest smooth.

Initially, you get a strong odor while applying but it dissipates in a few seconds after exposure to air.

Surprisingly, the sealant has insulation properties: This feature makes it stand out from the rest of the adhesives/sealants on the market.

Moreover, this is the reason why it is the best for electrical wires etc. as it insulates them along the way.

  • Black.
  • Flexible.
  • Waterproof.
  • Insulates.
  • Strong.
  • Dries quickly.
  • The bottom bursts open if a little pressure is applied.
Permatex 81158 Black Silicone Adhesive Sealant, 3 oz. Tube, Pack...
  • Professional Formula - This Black Silicone Adhesive Sealant Is A...
  • Do It All- Seal, Bond, Repair, Mend And Secure Glass, Metal, Plastics,...
  • Resist The Elements- Permatex Black Silicone Adhesive Sealant Is...

10. Surebond High-Temp Silicone Sealant – Number One in Construction Industry

Surebond High Temp Silicone Sealant


We know the construction industry deals with high-pressure machinery all the time. Hence, the sealant used should also be able to withstand those extreme pressures easily.

Therefore, Surebond has introduced a sealant that insulates thermally and electrically to ensure durability and reliability.

Is it only restricted to the construction industry? Certainly not. Multiple industries swear by the performance. For example, automotive, electrical, HVAC, Plumbing, Marine, Manufacturing, and Architectural.

All the big shots, right? It can easily be applied to rubber, wood, plastic, fiberglass, painted materials, metal, concrete, and glass.

As the name suggests, it gives excellent results in high temperatures. The reason being its non-flammable nature.

Usually, sealants take their time to cure. But, this cures fast. You can touch it within an hour.

The application process is very simple, easy, and time-saving. First, you need to make sure the surface is clean of any oils, dust, release agents, or dirt. Once it has been made sure it is clean and dry, you are ready to go.

Now, cut the nozzle at a slant for maximum efficiency and puncture the inner seal. Having that done, keeping a steady pressure, apply the sealant.

It hardly takes 5 minutes to make it tool ready. Furthermore, within an hour you can touch it with your bare hands.

Unlike others in the market, it can easily be used on the inside of the fireplace. Reason being, the non-flammable nature.

It also allows dissimilar materials to move around within the functional temperature range.

Furthermore, it is weather and water-resistant like its counterparts. No amount of water and sunshine can damage the sealant. Not only is it resistant to these, but it is also resistant to mold and mildew.

Amazing results at such a low price: This is surely a great find. It works just like any expensive brand works and gives the same results. But, at almost half the price.

Hence, the window seal replacement cost decreases manifold. So, what are you waiting for?

  • Long-lasting.
  • Strong.
  • Water and weather resistance.
  • High quality.
  • Economical.
  • Needs to be discarded or fully used after one application.
Surebond-SB-188 T High-Temp Silicone Sealant, 10.3 fl. oz....
  • High-temperature silicone sealant
  • Insulates electrically and thermally
  • Item Package Dimension: 8.0" L x 6.0" W x 11.5" H

Buyers’ Guide

Sealant for UPVC Windows Buying Guide

Before you even think of looking around for the Best sealant for UPVC windows, first familiarize yourself with what a sealant is.

Once that is done and dusted, read on to find what to look for in a sealant.

Admit it. How many times have you walked in a shop and looked around blankly at the number of options available?

Been there, done that! A mistake people often make is that they go to the store and grab the cheapest option available.

Please, refrain from doing that! So, without further ado, let’s dig in and see what to look for to find our perfect sealant.

What Can It Be Used for?

First things first: You need to be clear about what job you need the sealant for.

If it will be used only for the windows and doors, look for one which is compatible with them.

On the other hand, if your job requires you to work with water, you will surely buy one which is water-resistant and works well around water.

Undoubtedly, the first thing which comes to mind is to find a sealant that does it all.

Sorry to burst your bubble: But such a sealant does not exist.

Generally, they are multipurpose and have versatile uses, but you should go for one which is specifically made for the job on hand.

Normally, they can be used for a wide range of things.

But again, the sanitary sealants are more appropriate for use in the bathroom and around water as they are resistant to mold, water, and mildew growth.

Getting the hang of things, aren’t we? This is a key aspect to consider, is to check whether it is explicitly mentioned as being an outdoor or indoor sealant.

Resistance – How Much Can It Take?

A sealant that is resistant to the following should be your first option to buy:

  • Water.
  • Weather.
  • Dust.
  • Dirt.
  • Thermal.
  • Oil.
  • Release agents.
  • Mold.
  • Dew.

Water and weather resistance are a MUST. Apart from that, the more the merrier.

A higher resistance level guarantees better performance.

As there is hardly any situation in which the sealant will not be exposed to water, hence being waterproof is a must.

Generally, all sealants are waterproof. I have yet to come across one which is not.

Temperature – Let’s Heat Things

Be it outdoors or indoors, temperature fluctuations are always present.

Moreover, in industries like automotive, manufacturing, construction, marine, etc. things get hot.

Therefore, always check the maximum and minimum range of temperatures the sealant can endure.

Good-quality sealants can withstand temperatures from as low as -37 degrees F to a maximum of 450degree F. A lot, isn’t it?

A thing to note here: As already mentioned, sealants are weather-resistant and can endure extreme pressures once they dry out.

But it is very important to keep a check on the temperature while you are applying it.

It is imperative to know that excessive heat or cold can hinder the adhesive properties of the sealant during application. Hence, always apply it at normal temperatures and refrain from doing so in extreme weather conditions.

Cure – How Long Does It Take?

Another thing to consider is how long the sealant takes to cure. It can be anything from 30 minutes up to 24 hours or more even.

Again, it depends on the task at hand.

If you have ample time and can wait, a sealant that cures in 24 hours is okay for you.

On the contrary, if you are using it professionally, you do not have that much time.

So, you need to go for one which cures quickly and easily.

Modulus – High or Low?

types of sealants

There are two types of sealants when considering the modulus:

  • Low modulus.
  • High modulus.

Low modulus: are used for sealing curtain walling, glazing of windows, glass wall assemblies, etc.

Hence, for UPVC windows, low modulus sealants are the best.

High modulus: are recommended to use in bathtubs, sinks, swimming pools, and aquariums.

Hence, look for the one that suits your job.

Odor – What Stinks?

Are you tired of smelly, stinky sealants? Surprisingly, there is no reason why they should have such a strong smell. Of course, I know they are made up of chemicals, and chemicals have a strong, bitter smell.

Nevertheless, manufacturers can cushion that smells very easily. Not only is the smell unpleasant, but for people with respiratory problems, sometimes it becomes very overwhelming.

Therefore, go for a sealant that does not smell that bad.

Plus, if you have any respiratory problems, let it dry and leave the place. Don’t stand there.

For me, finding a sealant with the least odor is very important.

Price – How Much Can You Pay?

Finally, decide what price are you willing to pay?

Surely, it is a personal opinion, but let me tell you one thing.

While dealing with tricky products like sealants, quality should be the first preference, and then decide if you are going to pay the price. Generally, quality is synonymous with price.

Other features – What Else?

Following are other features to look for:

  • Low shrinkage.
  • No cracks.
  • Color does not fade away.
  • It does not blemish metals.
  • Nonflammable.
  • Tack-free.
  • Strong.
  • High elasticity.
  • Flexible.
  • Hazardous content.
  • Substrate compatibility.

Tips – How to Get It Right the First Time

Tips When Applying Sealant

We have got a few tips up our sleeve to help you get the perfect application in the first attempt.

Read on to be impressed!

  • Tape it up: This tip is not only for beginners but can be used by pros also. It is best to apply tape to control the sealant line. So, put two thin tapes on either side where you will apply the sealant. Once you are done, remove them immediately. As a result, you will get a perfect line of sealant and no excess.
  • Push the sealant in: Usually, we tend to drag the sealant over the gap. However, what should be done is to push it in with a little force, so it fills up the gap.
  • Go with the flow: use your body to move the tube along, not your wrists. Doing so will make the line perfect.
  • Don’t go over: Sometimes, there are long beads to run. Of course, you can’t get it done in one go. Therefore, once you have stopped, don’t go over the same place. It will result in a glob. What should be done here is to start at the other and meet in the middle.
  • Reusable sealant tape: How many times does the sealant dry in the tube. It always happens that when you open the sealant to be used later, the tip has dried sealant stuck in it. Now, you can easily get rid of it and use the fresh one beneath. All you need to do is cut two thin slits along the sides of the tube and push out the dry one from there. Moreover, block the slits with tape and use the fresh one easily.
  • Use straws: For those tight nooks and corners, put some sealant in a straw, make a slanting nozzle, and apply it with the straw for perfect coverage.

Yes, follow these tips and tricks to become a pro in no time.

Frequently Asked Questions

Q. How to go about sealing window frames inside?

Firstly, remove the old sealant. Secondly, make sure the area is dry and clean. Thirdly, apply the sealant consistently and evenly to all the joints of the window frame. Don’t forget the joint between the wall and the frame.

Q. How to seal windows with silicone?

Get hold of your caulk gun. Scrape out the old sealant and prep it by drying it. Open the sealant and load it in your gun after opening the seal.

Hold it at a good angle in the joints of the window and go in with the application. Once done, use a smoothing tool to smooth it out.

Q. How to replace rubber seals on UPVC windows?

It is very easy to take the rubber seal off. All you need to do is pull the entire thing off. Mostly, it comes off in one go. Now, use the knife all along where the rubber seal was placed to remove any buildup.

Next, get the new rubber seal out and start pressing it down where the original one was. Do it on all 4 sides evenly. Now, apply the silicone sealant where there are gaps in the corners. Moreover, don’t close the windows before it sets.

Q. How to remove silicone sealant from UPVC windows?

Firstly, you can apply for a silicone-eater. Keep it on for a couple of hours. You can skip this step too. Take a painter’s tool and start scraping off. Pull the rest with your hands. Clean the rest with rubbing alcohol.

Q. Can you use bathroom sealant on your windows?

If it’s silicone, you can use it for your windows. But it will not give the results a special window sealant will give.


By now, you must have decided which is the best sealant for UPVC windows. Moreover, you must have made the choice about which one to buy.

The 10 sealants we have included are durable, elastic, flexible, long-lasting, and economical. Furthermore, they can be used both indoors and outdoors. Hence, suitable for UPVC windows.

Don’t like any one of the selections? No need to worry. Our detailed buyers’ guide will help you further. Also, our tips and tricks will make you a pro in no time.

So, let’s get the party started! Go ahead, grab a sealant, and get to work.