From time to time, we get asked a question that shows how thoughtful our clientele can be. One such question is do you caulk or prime first. This is a great question to ask your painter! Not only do we have an answer, but we have an explanation and are happy to tell you all about it. In fact, there are a few different ways to approach this question. First, is the siding and trim painted or is it raw wood or other substrate. Second, what kind of caulk are we using on the project. The assumption we will make here are that the wood or siding is bare and the caulk is a premium grade urethanized acrylic.

The short answer is that we prime and then caulk. No matter the gap size, the job that is asked of caulk is not easy task – to expand and contract at all the wrong moments. So, let’s say it is 110 degrees outside. This pushes the gap together as the substrate expand with heat and the caulk compresses. So far, not too difficult! But take the winter months, the bulk is cold and more rigid at the same point the substrate is shrinking and stretching the caulk. Okay, don’t stress out! This is what caulk is designed to do. So why is is so important to prime first. It has to do with the grip of the adhesion. Caulk stick to primed wood quite a bit better than bare wood. So as the tension build to pull the caulk away from the wood and then back to pushing it into the wood, your caulk has a good and compatible surface to adhere to. This gives your caulk a better chance of sticking to it.

The short answer is that we prime and then caulk. No matter the gap size, the job that is asked of caulk is not easy task – to expand and contract at all the wrong moments. So, let’s say it is 110 degrees outside. This pushes the gap together as the substrate expand with heat and the caulk compresses. So far, not too difficult! But take the winter months, the bulk is cold and more rigid at the same point the substrate is shrinking and stretching the caulk. Okay, don’t stress out! This is what caulk is designed to do. So why is is so important to prime first. It has to do with the grip of the adhesion. Caulk stick to primed wood quite a bit better than bare wood. So as the tension build to pull the caulk away from the wood and then back to pushing it into the wood, your caulk has a good and compatible surface to adhere to. This gives your caulk a better chance of sticking to it.