Step 7: Apply Caulking Between Trim and Siding

When it comes to siding, caulk seals and prevents moisture/water from penetrating and damaging your home. Apply it to corners, cracks and trim boards for windows, doors, and butt joints. Although, it is relatively easy to go caulk crazy and start applying it all over your exterior, incorrectly applied siding caulk or overuse of it can cause damage to your exterior. Try thinking about where you shouldn’t apply it before you start.

For example, you typically should not be caulking wood siding as it restricts the natural expansion and contraction of the wood due to changes in temperature and humidity. Caulk should also not be used on fiber cement siding as it conflicts with metal flashing (which acts as a water-resistant layer). No caulk should be applied to trim boards that reside on top of your siding surface because it restricts air circulation and promote dampness (encouraging mould). Lastly, the bottoms of horizontal siding or tongue and groove panel edges should not have caulk applied because it would prohibit the natural “run-off” waterproofing of horizontal siding and restrict standard functionality.

Material

There is a wide variety of siding caulk to choose from, and while prices vary, quality is the most important factor. Siding caulk comes in latex, silicone, butyl rubber, a mixture of ingredients, and more. There are different caulks for different uses, and we strongly recommend that you consider an outdoor, weather-resistant caulk when working on an exterior project.

We recommend:

Butyl-rubber caulk because it is a strong and durable outdoor caulk that can withstand the elements. You can use other caulk options, but we implore you to read the labels carefully and be sure that the caulk you choose is the perfect caulk for your project.

Colour

Some homeowners find it preferable to match their caulk colour to their siding colour. If you wish to do this, we recommended that you choose a shade slightly lighter than your siding so that the caulk does not draw more attention than your beautiful siding. Furthermore, caulk and siding colours won’t match exactly (unless a siding company has pre-matched colours), so it is important to keep this in mind when colour-coordinating. Regardless of colour, you should still make sure that the type of caulk your particular application.

DIY Caulking Tips and Tricks

We recommend that you invest in a good quality caulking gun that is a larger size. Larger, better quality guns are more precise than smaller and lower quality guns, which saves you time and money in terms of clean-up and the amount of time spent refilling. Always have a towel or rag readily available to clean up and smooth excess caulk before it sets. If, at any point in the process you feel that your project is beyond your capability, we highly recommend that you speak with your Build-It-Better coach about hiring a contractor. Hiring a contractor gives you less stress and the peace of mind that comes with hiring a professional.

How to Apply Exterior Caulking Properly