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Caulking Failures : The Chink In Your Home’s Armor

TLDR : The Main Takeaways If You Don’t Have Time to Read The Entire Article

  1. Caulking is used throughout the entirety of your home’s exterior and is probably the single most commonly overlooked element of your home’s well-being

  2. Caulking fills the spaces between the toughest elements of your home’s exterior, helping to prevent harmful effects of weatherization and the intrusion of pests

  3. Typically, failed caulking isn’t recognized by homeowners until they have already experienced more significant issues stemming from it - such as wet rot, failed siding and/or infestations of bugs or rodents

  4. Inspecting your caulking once a year and replacing it every 5 years along with your paint is recommended by building inspectors here in Washington & Oregon to ensure long-lasting protection of your home

Caulking : The Canary in the Coal Mine

Caulking is one of the first and most important indicators of your home’s well-being. It is also one of the single most overlooked aspects of the home - especially on the exterior. There are a few reasons for this; mainly it’s not one of the most visually impactful components regarding the look of your home. But, it is one of the most impactful components when it comes to the safety of your structure and the longevity of it. When caulking begins to fail it usually goes unnoticed because it can only be witnessed upon close inspection, may or may not be painted over (hiding it’s most apparent aspects from plain sight), and when it is seen as an issue it’s often regarded as a minor imperfection. While visually failed caulking can be considered a minor imperfection - it can actually be the tipping point for a host of other issues that result in larger repairs for homeowners.

Step 1 : Knowing what caulking is and where to find it on your exterior

Caulk (pronounced /kôk/) is a waterproof filler used to seal a gap or seam in building work and repairs.

caulking is used extensively throughout the exterior of your home and can typically be found in every transition space between different products, where one material terminates and another begins sometimes overlapping (e.g. the horizontal siding stops here and the vertical trim begins). The most common transition spaces that your home is likely to have are between siding and trim (around every window and door) - between siding and corner boards - between siding and vents & light blocks. This number of placements may surprise you. As we said before it is used extensively and is commonly overlooked, but that doesn’t negate its importance - instead it reinforces it.

These transition spaces are filled with sealant which prevents moisture and pests from entering your home’s components.

Purpose : Protection

Caulking is used to weatherize your home and to prevent damaging elements from entering your home’s building envelope. Damaging elements for your home’s exterior mainly include moisture (water and water vapor). The rapid temperature swings that generate moisture (like those often found locally in Washington and Oregon) can take a heavy toll on the building components of your home. Imagine you have a wedge of cheese in a container that you’re constantly taking in and out of the fridge, that temperature swing creates excess moisture in the container. As you well know, it won’t take long for that cheese to grow mold and become unusable. In effect, that’s similar to what is happening to your home. The temperature fluctuation leads to increased moisture and the rapid onset of mold or mildew and begins to breakdown the protective and structural elements of your home, caulking helps to prevent moisture from entering - thus negating the ability of mold and wet rot to occur. Your home is obviously much more precious than a wedge of cheese and deserves all the protection as can be afforded.

The protection that caulking affords becomes especially important at different times of the year - such as the beginning of winter here in the Pacific Northwest because the rain begins (filling the air - and potentially your building components with moisture) and cooler temps cause insects and animals to seek shelter. Homeowners usually recognize this time not only because of their need for a coat - but also the appearance of more spiders and insects in or near their home. If you begin to have unwanted house guests as we move from Fall to Winter it’s likely you have failed caulking through which they are gaining access to your interiors.

Step 2 : Understanding Failure & Its Implications

As we’ve mentioned the leading causes of failure are harsh temperature swings and excess moisture. Typically these go hand-in-hand. Something else to note, because we feel that it may come as a surprise to most, is that excess moisture can also come from your landscaping. Yes, believe it or not - the vegetation (bushes, hedges, flowers, etc.) within a couple feet of your home can exacerbate the moisture issues as well. This usually happens for a few reasons (1) they require irrigation. That irrigation is often over sprayed onto the home and saturates the components there. Depending on how dense the vegetation, the evaporation process may be lengthy - leaving your home saturated for an extended period of time. (2) Even if you don’t irrigate the nearby landscaping yourself - mother nature surely will. And rainfall splashing off your plants and onto your home can have the same effects of over saturation and prolonged windows of moisture because of decreased evaporation. (3) The close-in vegetation surrounding your home can also create increased humidity within it’s shade - which of course means more constant moisture. (4) Plants attract animals. Bugs and rodents are attracted to plant life. When the plants become a food source or a hunting ground the creatures they attract generally seek refuge somewhere very nearby. This usually leads to pests attempting to infiltrate your home’s siding. You have a warm dry place inside your building envelope and if they can penetrate it - they’re likely to flourish within your walls. (5) Sunlight and pollen. Yes even these have a role to play when considering the impacts on your home. Excess sunlight being reflected off plant life and the pollen released both have an effect on your home’s building components. We utilize James Hardie products. They’re really the most well engineered products on the market and tough as nails (maybe even tougher) when it comes to standing up against adverse weather conditions. And we utilize polyurethane based caulking for the same reasons. They’re both tough, durable and afford top-notch protection for you and your home.

In the photo below you can see the mold that begins to form on the inside of siding if your caulking has failed and the deterioration process has begun.

Step 3 : Who Should Be Caulking & When

It is being recommended by local 3rd party building inspectors here in Oregon and Washington to have the caulking of your home checked every single year and replaced every 5 years with your paint. There are a host of other Winterizing items to perform yearly in order to protect your home - it’s probably easiest to just add a caulking inspection to the list.

We recommend a close visual inspection of the caulking of your home’s exterior to look for slight cracks (even small cracks can let in enough water vapor to begin the deterioration process for your home’s important structural and protective components). Of course, if your home has a second story - it can be a real pain to position yourself close enough to properly inspect all of your caulking. In this case, you may want to seek an expert’s opinion. The inspection of caulking should be taken seriously because as soon as it begins to fail the cycle of deterioration begins.

Below you can see what good, protective caulking looks like. If your home’s caulking is as solid as it is in these pictures below then you likely have nothing to worry about right now, but should continue to inspect it yearly AND contact a professional when you begin to see a change. What may help with this is taking an up-close photo of your caulking to use for comparison the following year. We recommend this practice because most homeowners’ memories for caulking appearance is relatively short. Generally caulking isn’t top-of-mind and often receives the “looks good to me” treatment - but having the visual reference from the previous year will really help homeowner’s detect any changes in its ability to protect their home from harmful elements.

A Word of Warning : Any Failure Is Enough To Cause a Headache

If your caulking is beginning to deteriorate (as it typically does in 5 year cycles) then you ought to have it inspected by a professional because it likely is already causing unseen issues for your home and future finances. Two main proponents of caulking degradation (temperature shifts and excess moisture) generally lead to two separate caulking statuses. (1) Way too wet and (2) way too dry. In an overly wet scenario the caulking begins to loosen its grip and can be seen becoming detached from the building materials. The adherent properties of caulking begin to weaken causing it to fail In the photo below you can see what this might look like.

In a way too dry scenario (which we do see locally here in Oregon and Washington - typically during Summer) the caulking contracts in the heat, reducing its ability to adhere to building materials, but also forming hairline cracks that basically spell the beginning of the end for its ability to protect your home. Hairline cracks can be so faint that they look as thin as a strand of hair - hence the name. Obviously that sounds pretty darn small. But just know - that even though they’re small - their implications for your home are not. In the photo below you can see cracking beyond ‘hairline’ this type of cracking undoubtedly allows a lot of moisture (and potentially pests) into your home.

Step 4 : Act Now - The Longer You Wait The Worse It Gets

As they say, “Hindsight is 20/20” don’t let this be the year you had to learn these lessons the hard way. We have seen record highs this year and now we’re entering the Winter, which has been predicted to be especially wet by some and especially cold by others. All that indicates the temperature swings happening right now are going to be an intense and demanding time for your home. Please take it from us, we’ve been in this industry for most of our lives and we’ve seen the damage that can occur from unintentional neglect. As a homeowner you’re better safe than sorry when it comes to being a little too relaxed about a sub-par caulking situation. You deserve a great home and that home deserves great protection. Give us a call to set up an inspection and free estimate. We’re serious about the protection of your home’s exterior and are happy to help solve the issues that failed caulking can cause.

Call Today for your Free Estimate : 360-718-8694 or email


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