How To Properly Seal Around Pipes Under Your Kitchen Sink

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Sealing around pipes under the sink is one of those things that most people usually neglect or don’t think about.

Sealing around pipes under your sink is essential to prevent water damage.

Water damage can cause mold growth and mildew, leading to health issues.

But sealing around pipes under the sink can prevent leaks and save you money in the future. 


What You’ll Need To Do The Job

You will need a few tools, including a putty knife, plumber’s snake, pipe cutter, and some caulk.

You will also want to access your plumbing supply store for any additional supplies needed.

So what exactly do you need to know about sealing around pipes under the sink?

And how do you go about doing it?


How To Seal a Pipe Properly In 4 Easy Steps

1. Check Your Plumbing System

Before you begin any plumbing project, first check your plumbing system. Make sure there aren’t any pipe leaks or cracks anywhere in your home.

If there are, then you’ll want to repair pipe leaks before trying to seal any pipe.

This is particularly true if you’re working near main water lines.  

2. Use The Right Sealant

Once you’ve checked your plumbing system, use a sealant to fill any gaps or cracks you find.

Caulk is a type of sealant that comes in various colors and textures. The two main types are silicon and regular caulk.  Both work fine for sealing around pipes.  We prefer silicon over regular caulk, however, due to its resistance to peeling and cracking over time.

Caulk comes in different colors and textures, as well.

Some types of caulk are made specifically for plumbing systems, however.  Look for those.

3. Apply Caulk Around Pipes Under Sink

fill gaps around pipes under sink

After you’ve filled any gaps or cracks you found in your plumbing system, apply caulk around pipes under the sink.

Apply caulk around pipes under sinks using a brush or trowel.

Make sure to cover every inch of pipe under the sink.

When applying caulk, make sure to follow the directions on the package.

For example, read the instructions carefully, so you know how much caulk to use and where to apply it.

Don’t forget to let the caulk dry completely before moving anything else.

4. Clean Up After Yourself

Finally, clean up after yourself after you finish installing your plumbing system.

Clean up any leftover sealant or caulk.

Use a sponge or rag to wipe down any surfaces touched by the sealant or caulk you used.

It’s essential to clean up after yourself because some sealants and caulk contain chemicals that could harm pets or children.

In addition, if you didn’t properly clean up after yourself, you may end up with a mess that needs to be cleaned up later.

That would be a waste of time and money.

So take care of yourself and your family by cleaning up after yourself.


Use Spray Foam Around Pipes

fill gaps around pipes under sink

We recommend Great Stuff to seal gaps around pipes. Even though her post was sponsored by Great Stuff, the advice she gives is still good. You don’t have been using Great Stuff, but other brands, such as LOCTITE Tite Foam, work just as well. Most spray foams contain liquefied polyurethanes, which expand into a hardening foam. They completely fill gaps up to two inches wide and sometimes more!

Polyurethane has little to no environmental effect, and it sticks permanently. It’s made from hardening foam which provides thermal insulation and it’s impervious to pests. Rats can’t chew their way into it, and when applied properly it doesn’t leave any gaps for bugs.

If you want to ensure that the foam will keep pests out, you can choose Great Stuff Pestblock Foam, but it contains no pesticides. Since the PestBlock foam costs twice as much, you may as well go for the cheaper option and save the money instead.


How to Use Spray Foam

It’s easy to use, but you need to be careful because it sticks to everything. It’s hard to get rid of. Solvents won’t dissolve it, and if it gets on your hands, clothing, or the sink cabinet, then mechanical removal is required. You can’t always get rid of it, so wear old or throwaway clothes when using them.

The foam comes in an 8-ounce aerosol can. Place the tube on the nozzle, place the tip of the tube into the gap, and press down on the trigger. Fill the gaps halfway, and the foam should expand to fill the rest of the gap. Make sure you keep a rag nearby so you can wipe up any drips from the nozzle before they drip down into the bottom of the cabinet, which could cause damage.


Other Ways to Fill Gaps

If the pipes under the kitchen sink are exposed, then you probably don’t want to cover them up with spray foam. It’s not the most attractive material in any event. If the gap is less than about 1/4 inch wide, you can use caulk to seal it; if it’s wider, you can stuff it with steel wool and caulk over it.

Another even more attractive way to patch drywall around pipes is by filling the gaps with patching compounds, which a powdery substances that sets hard when mixed with water. Apply a layer of joint compound, wait for it to set, and then sand it down. After painting the walls, finish them off by applying another coat of paint.


Frequently Asked Questions

fill gaps around pipes under sink

What Should You Use To Seal Pipes Under a Sink?

There are two ways to seal around pipes under the sink.

First, you can use caulk. Caulk is a type of mineral-based adhesive used to fill gaps between surfaces.

Second, you can use silicone caulk. Silicone caulk is a flexible, waterproof substance that dries quickly.

Which Type Of Caulk Should I Use?

Both types of caulk – silicon and regular caulk – are effective.

However, silicone caulk is better than regular caulk because it doesn’t crack or peel as easily.

How Much Caulk Should I Apply?

Apply enough caulk to cover the area where the pipe meets the wall completely.

Use a small brush to apply the caulk.

Make sure to leave an inch gap between the caulk and the edge of the hole.

How Long Does It Take For Silicone Caulk To Dry?

Silicone caulk dries within 24 hours.

After this period, you should wait another 12 hours before applying additional caulk.

Doing so ensures that the first layer of caulk has dried properly.

How Often Should I Replace My Caulk?

Replace your caulk every six months.

The recommended replacement interval depends on the type of caulk you’re using.

For example, silicone caulk requires replacing every year.

Regular caulk needs replacing every three years.


How To Prevent Water Damage In Your Home

Preventing water damage via leaks in your home is simple.

Follow these steps to ensure that your pipes don’t leak.

Check Your Drain Line

Before you begin any plumbing project, check your drain line.

Look at the drain line to see whether it is clogged.

If it is clogged, you will need to clean it out.

Clean Out Any Clogs In Your Drains

Drain lines usually become clogged over time.

To remove any clogs, you will need to use a plunger.

Place the plunger inside the drain line and press down firmly.

Remove the plunger after 15 minutes.

Once you’ve removed the clog, rinse the drain line thoroughly with warm water.

Fix Leaks That Are Already Present

Leaks can occur anywhere in your house.

If you find a leak, fix it immediately.

Leaky pipes can cause serious problems if they aren’t fixed right away.

Contact a local plumber as soon as possible to help you repair the problem.

Now that you know how to seal around pipes under sinks, you should prepare well for the upcoming summer season.

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