Commercial, Mixed-Use and Strata Roof Maintenance in Vancouver, B.C.

Exterior Caulking: (It’s 5 Types And EasyTips For Application)

Exterior Caulking: (It’s 5 Types And Easy Tips For Application)

If you know how cracks, edges, and seams are sealed, then you must be aware of Exterior Caulking It’s one of the most common repair products that are easy to use and readily available. But did you know there are different types of exterior caulks?

Exterior Latex Caulk, Butyl Rubber Exterior Caulk, Exterior Polyurethane Caulk, Exterior Acrylic Latex Caulk and Exterior Silicone Caulk are the 5 most used exterior caulk.

In this article, I have covered the difference between each of these types. Along with the tips on choosing the best exterior caulk for your roof. Plus, you will also find things to keep in mind before exterior caulking.

What Is An Exterior Caulk?

An Exterior caulk is a thick solution, that is used to seal cracks, edges, seams and breaks in the exterior of a structure. It is generally made up of silicones, polyurethanes, synthetic rubbers, acrylic latex, butyl rubber and many combinations thereof.

It comes in a portable long tube which is easy to handle. This is a comparatively inexpensive sealant which is used by professional roofers, construction contractors and DIY enthusiasts alike.

How to choose a Perfect Exterior Caulk?

Before diving into the ins and outs of selecting an appropriate exterior caulk. It’s important to understand there are two types of caulks. Exterior and Interior.

Each of these is specifically designed to fit the user’s needs. You cannot use them interchangeably. As each can withstand different environmental conditions.

Initially, interior caulks were paintable, but exterior caulks weren’t. Now, with improvements in technology exterior caulks can be painted too.

While picking a caulk it’s important to know the purpose for which you will use it. And purchase the one specially made for it. There is no one-size-fits-all when it comes to caulking.

Below are some things to consider prior to buying an exterior caulk.

Easy To Use?

Caulks are usually sold along with a caulking gun. All you have to do is place the caulk tube in the gun and press the trigger to squeeze out the caulk.

However, usability goes beyond this. You must consider the adherence and viscosity of the caulk. Butyl rubber, polyurethane, and silicone caulks are dense and hence difficult to apply.

Latex and acrylic latex caulks are relatively more viscous. So easy to use. There is always a possibility of overapplication. Luckily, these caulks are non-messy and easy to remove.

Is It Durable?

Roofs usually go untouched for months, sometimes even years. So, it’s essential to pick an exterior caulk that can handle the elements without breaking itself.

Silicone, polyurethane, or butyl rubber exterior caulk are perfect for roofing. As they are more durable than latex and acrylic latex. Silicone exterior caulk is water resistant, but not compatible with wood. However, polyurethane goes well with a majority of roofing materials.

Latex and acrylic latex, are rigid and do not expand and contract as per other roofing materials. This causes early wear and tear.

What’s The Curing Time?

Curing time is the time required for an exterior caulk to completely dry from the inside out. Ideally, an exterior caulk may dry in about 30 minutes to an hour.

However, depending upon the climate, humidity, location on the roof, and amount of caulk applied. It may take anywhere from 1 hour to 6 days for the caulk to completely cure and adhere to the surface.

A thick bead of exterior caulk may take significantly longer to dry from the centre. Lesser the curing time better the caulk.

Which Colour To Pick?

When it comes to the roof, aesthetics matter!

Therefore, an exterior caulk that matches the shade of your roof is a good choice. Polyurethane exterior caulks are a good base for paint. However, most 100% silicone caulks cannot be painted.

Latex and acrylic latex exterior caulks can be painted buy, but these caulks are not durable.

Exterior caulks are being sold in multiple shades so select the caulk that suits your needs and matches your roofing colour palette.

While a clear or white coloured caulk blends well with most of the roofing systems.

Types Of Exterior Caulk.

Get to know all the available exterior caulking options available in the market.

Exterior Latex Caulk.

If you live in a place where the temperature is pretty consistent, then exterior latex caulk might be perfect for your roof. As it does not contract or expand as per its surrounding materials once cured.

This exterior caulk is paintable, but if the temperature is extreme the paint may chip, flake and crack.

This is the most inexpensive caulk but is short-lived. And needs regular reapplication to maintain the seals.

Butyl Rubber Exterior Caulk.

Butyl Rubber Exterior caulk is U.V. and temperature resistant. Hence its typically used in commercial and industrial settings, where sun exposure is constant.

Butyl Rubber Exterior caulk is perfect for roofing. As it seals chimneys flashings, gutters and areas with HVAC and other equipment perfectly well.

You can apply this caulk at any temperature. Nevertheless, take care while applying this exterior caulk.

Exterior Acrylic Latex Caulk.

If you want an exterior caulk that is more water resistant than a Latex caulk, this is the product for you. It’s equally affordable and easy to apply. However, it has all the drawbacks of latex caulk.

It is best for wood, tiles and metal along with some other materials.

Exterior Silicone Caulk.

Exterior Silicone caulk is one of the most durable exterior caulks. Even after curing it adjusts itself as per the surrounding materials, as its flexible. It’s paint resistant, but available in various shades to match your roof.

It’s compatible with mostly all materials including wood. It’s tough to remove this caulk after application, and neither is it beginner friendly. DIY lovers should get the hang of it before applying it to the roof.

Exterior Polyurethane Caulk.

Exterior Polyurethane Caulk is a mix of Butyl Rubber Exterior Caulk and Exterior Silicone Caulk. As it has properties of both the caulk.

It’s U.V. resistant and flexible. Therefore, it can be used for both residential and industrial roofs. It can take paint so you can match it with your roof’s shade. Moreover, it works well with several roofing materials including glass and wood. Making it a perfect sealant for skylights and other roofing layers.

Yet, it’s not meant for DIYers. It’s extremely thick and needs professionals to use and remove it.

Things To Consider Before Exterior Caulking.

Now, that we know the different types of caulks and how to pick the best one for your roof. Let’s see a few things to consider before exterior caulking.


As mentioned above, the caulk needs to cure. Which vastly depends upon the temperature. If it’s rainy or extremely humid the caulk won’t dry as expected, reducing the quality of adhesion. Resulting in improper sealing.

If it’s too windy, the dirt and debris might blow into the caulk solution and disturb the curing process. If it’s too hot, the sunlight might dry off the caulk too quickly to form a tight seal.

A dry cloudy day with a temperature of approximately 35-40 degrees Fahrenheit is perfect for exterior caulking.

Style Of Application.

For a consistent, clean and continuous result, you might be tempted to apply a single uniform line of caulk. This method may seem foolproof in theory. But in reality, you will end up emptying your entire gun.

Apply consistent shorter beads of caulk, that merge in the end. This will give a more polished result.

Are You Using The Right Caulk?

As stated above, not all caulks can pass as exterior caulks. While picking an exterior caulk for your roof. Make sure it is water resistant, flexible, durable, and can withstand the test of both time and the elements.

Is It The Right Place For Caulking?

The exterior caulk is meant to seal small holes, cracks, gaps, seams, etc. However, some parts of the roof are better unsealed, than sealed.

The roof breaths, it contracts and expands as the seasons change. If you end up caulking any and every gap/hole in the roof you may prevent ventilation and trap moisture.

Therefore, proceed with caution.

Hire An Expert Roofer.

No one can caulk your roof better than a roofer. I know exterior caulking is considered to be a DIY activity. But, caulking up on the roof or in any part of the roofing system is more complex than just pressing the trigger of a caulking gun.

If you want to get the job done right on the first try, connect with a reliable roofing contractor.

Can Exterior Caulking Be a Potential Cause Of Leaks?

Exterior caulking only lasts for 5 years and needs to be replaced periodically.

U.V., rays, wind, snow, dirt, dust, debris, etc. takes a toll on it. Which causes it to chip, crack and eventually fall off.

If not reapplied in time it may wear, leaving your cracks, holes and seams exposed. Which could be an entry point for water. Eventually causing leaks and water damage.


I hope this article offers a detailed introduction to exterior caulking. If you wish to add anything to the above comment down below.

We are forever ready to answer your questions and fulfil your roofing needs. For professional roofing services connect with Leakstop Today!

Leak-Stop is a one-stop destination to meet your roofing-related requirements. We offer roof repair, replacement, maintenance and inspection services all over GVRD (Greater Vancouver Regional District).

We offer a free inspection to first-time clients. Connect with us TODAY at 1 866 777 0084 for immediate assistance!

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