Should You Caulk Vinyl Siding?

Are you installing new vinyl siding? This is an excellent choice for redirecting water away from your home's foundation. With vinyl's waterproofing abilities, you may wonder if you will even need to caulk to seal the siding. We have done the research and have all you'll need to know about caulking your vinyl siding.

Yes, you should caulk vinyl siding in the necessary locations. They should be caulked where connecting pieces of siding meet as well as at corner joints. Silicone caulk is the best waterproof caulk for use on vinyl siding.

Caulk is the go-to waterproof sealant used in outdoor projects. Even so, there are some instances where spaces should not be sealed shut. Even in areas that are not sealed shut, there are ways to protect them from pests. Keep reading for more on caulking siding and preventing water damage.

A vinyl siding installation on a house, Should You Caulk Vinyl Siding?

What is the best caulk for vinyl siding?

The best caulk for vinyl siding is silicone caulk. It remains waterproof longer than other caulks like acrylic or latex caulk. Silicone is also superior for outdoor use because it resists mold, mildew, and damage from sunlight. It can last for up to fifty years before needing to be replaced.

Click here to see silicone caulk on Amazon.

Vinyl siding is very flexible and can stretch more than other siding materials. If your siding is stretching, it will put pressure on the joints where the caulk is. Flexible caulks like silicone form strong bonds and can allow for minor movements in siding. 

Does silicone caulk stick to vinyl siding?

Yes, silicone caulk will stick to vinyl siding. Silicone caulk will take a little longer to fully cure after application than other caulks. It will be dry to the touch after about thirty minutes. However, it will take about twenty-four hours to cure completely. After curing, the caulk is flexible and water-resistant.

After the silicone is cured, it will not stick anywhere besides where it was applied. With that being said, you are not able to paint over this kind of caulk. It can be found in clear, black, and white but cannot be customized.

How do you caulk vinyl siding?

Siding should be caulked together where the edges meet. This creates a continuous waterproof barrier throughout the siding layer. Your siding should also be caulked where the walls meet.

First, you will need to gather your caulking materials: the caulk and a caulking gun. To connect two pieces of siding horizontally, begin by placing them end to end with a very slim space between them. Then, you can dispense the silicone between the siding panels to connect them.

Check out this caulking gun on Amazon.

After applying the sealant to the small crack, you can use a caulk tool or a gloved finger to smooth over the silicone. Silicone caulk has a risk of skin irritation, so never touch the caulk with your bare hands.

You can find this silicone caulk tool on Amazon.

For sealing corners, you will need to put the caulk in between the wall siding and the corner siding piece. For a waterproof seal, you will need to place caulk around any touching parts. Essentially, on the corner piece, you should pipe the siding in and around the curves of the vinyl siding. This video gives a demonstration:


Can you put new caulk over old caulk?

Caulk creates a tight seal, so you should not apply a new layer over old caulk. Without being able to touch the siding, the caulk will not adhere or make a tight seal. If you are trying to redo any caulk, you will have to remove the old caulk first.

To remove silicone caulk, you will need to apply something to soften it. Then you can use a sharp tool to scrape off the caulk. Some liquids that can soften the silicone are isopropyl alcohol, vinegar, and WD-40. 

What happens if water gets behind siding?

Getting moisture behind your siding can mean troubles down the line. If water gets behind the siding and cannot escape, it can grow mold. The mold will release spores into the air and spread if left untreated. Mold is dangerous to everyone, but especially for those with weak immune systems or respiratory issues.

Dirty vinyl siding needs power washing

Water can also rot the sheathing on your house and damage the foundation. If the sheathing rots, the barrier protecting the inside of your home from wind and water will be damaged. Rotting can extend to the foundation walls as well.

Lastly, the damp environment can attract bugs. You can end up with a pest infestation that can damage your siding. Insects like carpenter ants are known to hollow out the wood in the foundation. Taking steps to prevent moisture from entering your foundation will help keep mold, mildew, and bugs away.

How to prevent water damage

There are a few ways to prevent water damage to the outside of your home. Waterproofing products like siding, sheathing, house wraps, and caulking all assist in waterproofing. The most effective waterproofing technique combines and layers many of these products.

Proper caulking on siding will be your home's best defense against water. It only takes a small amount of water to cause damage, so additional items like flashing help to drain away excess water. Flashing is a thin strip of metal that redirects water away from walls.

Should you seal the bottom of siding?

When you begin caulking, you may assume that you should put caulk in every open space for maximum protection. In reality, that can cause more harm than good. If water happens to get underneath your siding, it will need a way to escape.

For this reason, you should not caulk the bottom of your siding. Most water will be entering from the top down, so the open bottom will only allow water to drain. It will also let in more oxygen to dry the wall underneath.

How do you close the gap between siding and foundation?

Siding helps direct water away from the foundation, which is why the bottom should remain unsealed. There are things you can use to put inside the space to fill it in. However, it should not be closed off entirely without airflow.

Check out this rodent barrier on Amazon.

A rodent barrier is made to keep rodents out of gaps in your foundation or siding. The fabric is similar to steel wool and will still allow for water drainage. When choosing a steel wool fabric, make sure that it is stainless steel to resist rust over time.

To install the gap filler, first, you will need to measure the required length. Next, you can cut the amount needed and fold the fabric in half lengthwise. With the material doubled over, push it into the gap to fill it in.

Going around the perimeter of your home would take a lot of time to measure, cut, then install pieces individually. If you are working on long stretches of siding, you can fold and install the fabric as you go. This way, you can cut only when you need to and quickly move on to the next section.

This video demonstrates how to install this fabric:


Safety tips for working with steel wool

Using this product requires constant contact with your hands. This can cause skin irritation and pain, so always wear protective gloves while working with this product. 

While cutting the fabric, you are also exposed to the small particles of metal being cut. The dust and metal particles can cause eye irritation, so safety goggles should be worn if available. To increase your safety while cutting, use strong tools that are made for use on metals. Tin snips are a great tool for this purpose.

Click here to see these tin snips on Amazon.

Two wrap it up

Vinyl siding is an excellent choice to protect your home against water damage. Even so, siding alone will not be completely waterproof in your home. Using caulk to fill in small gaps and cracks in siding helps to create a waterproof barrier.

If water does get behind your siding, it will need somewhere to drain out of. Do not plug in the bottom space with nonporous materials. Breathable steel wool fabric allows for drainage while plugging in gaps to keep out rodents.  For more tips on siding, check out some of our other articles:

10 Of The Best Vinyl Siding Cutters To Check Out

Should You Caulk Wood Siding? [And How To]

Leave a Reply

Your email address will not be published. Required fields are marked *