How Do You Waterproof A Basement Bulkhead Door?

You have done all you can to keep your basement dry, only to discover the water is leaking in through the bulkhead. Does waterproofing the bulkhead door solve this problem? If so, how should waterproofing be done? We've consulted with the experts, and here are the practical solutions they offer.

You can waterproof the bulkhead door to stop the water from leaking into your basement by following these steps:

  • Replace damaged rubber seal.
  • Replace faulty or worn-out doors.
  • Seal the cracks in the bulkhead concrete foundation.

Keep reading to understand in-depth the causes of a bulkhead letting in water, how to stop the water leaks, when to replace a bulkhead, and how to maintain it properly.

A green basement bulkhead door with black eyed susan flower, How Do You Waterproof A Basement Bulkhead Door?

Why Is Your Bulkhead Leaking And How To Stop It?

The bulkhead is a valuable part of your basement because it allows you to walk in and out without having to pass through the main house. It provides a large entrance through which equipment and tools can easily be brought in and out whenever repairs are needed. Also, instead of the door being landlocked inside the house, it acts as an egress.

However, the bulkhead can be a source of misery if water is leaking through it. The following are ways in which you can solve this problem:

Replace Damaged Rubber Seal

If the rubber seal is worn out, loose, or has come out of place, then it either needs to be fixed back or replaced.

Weatherstripping or rubber seals will fill any gaps around the door and are very easy to install. They are available in various lengths and sizes, thus, you only need to identify one that fits snugly into the gap in question.

How To Install A Rubber Seal On A Bulkhead Door

Basement bulkhead doors on the side of building

The rubber seals are available in rolls so that you can cut and fit them to the dimensions of your bulkhead door. It takes a few minutes to install as explained below:

Tools Needed

  • Large scissors or tin snips
  • Rubber seal parts
  • 2 Cap seal gasket pads
  • Bulb trim gasket
  • U-shaped gasket

View this U-shaped rubber sealant on Amazon.

Check this bulb trim gasket on Amazon.


  1. Open the left door, and start fixing the U-shaped seal gasket to the header flange from one end to the other end and trim. Open the right door and follow the same process.
  2. Install the U-shaped seal gasket to the side panel flange of the left door, firmly fixing it from one end to the other, and trim where it ends. Repeat the same process on the right door. 
  3. Install the U-shaped rubber gasket on the left door center flange beginning from one end, firmly fixing it and when you reach the end, trim it. 
  4. Next, take the bulb trim gasket and install it to the left door leaf bottom flange, and then do the same to the right-hand door.
  5. Finally, take the door cap seals and peel off the adhesive on the backside and firmly place it at the top and bottom end of the right-hand door.

For better understanding, below is a video that shows you how to install the seal on a bulkhead door:

Replace Faulty Or Worn-out Doors

Water can leak in through the bulkhead door if it’s faulty, such as the hinges not working properly, not sitting properly on its frame, or if it is too rusty and worn out, among other issues.

If the fault or damage is not extensive, then you can carry out the repairs required, but if this will not help much, then you may need to replace the door.

Removing and installing a new door can be tricky, especially if the door is made of steel as it can be heavy. A professional is more adept at the task, and you might have to contact one if you want it installed correctly.

Below are two videos, the first one shows you how to remove a rusted bulkhead, and the second one shows you how to install a bulkhead door:

How to remove a rusted bulkhead door.

How to install a bulkhead door.

Seal The Cracks In The Bulkhead Foundation

After you establish there are cracks in the foundation, or leaks at the point where the bulkhead joins with the concrete foundation, the next step is to seal using a concrete sealant.

Identify where the cracks are located by noting where you mostly see patches of moisture, and then apply the sealant. However, before you do so it is important to dry the area using a high-powered fan.

Afterward, you need to install it on a day you are sure will be dry and no rains expected so that the sealant can dry properly. You can be on the lookout for the weather forecast to pick a good dry day.

Concrete sealers are available in different types. They work by bonding together concrete, and concrete with metal. Application is either by spraying or rolling. The most suitable sealants for basement jobs are the popular softer concrete sealers that are also affordable.

Have a look at this concrete sealant on Amazon.

How Long Will Your Bulkhead Last?

A basement bulkhead storm door

A bulkhead does not need a lot of maintenance, but it can last longer by following a few simple rules, which include:

  • Calling a professional several times in a year to check the door and the foundation surrounding it to determine if it needs repair or replacement.
  • Addressing moisture issues as soon as they emerge to prevent large-scale damage.
  • Regularly cleaning around the bulkhead both inside and outside.

When Do You Replace A Bulkhead Door?

As explained earlier in this post, a bulkhead will need to be replaced when it is worn out. Rust can cause a steel door to corrode creating spaces that can allow water leaks, or a wooden door can rot making it warp.

As soon as you notice signs that your door is no longer sound, it should be replaced as soon as you can. If you delay, water will continue seeping into your basement causing damage that is not only extensive but expensive.

What Is The Cost Of Waterproofing A Bulkhead?

Basement bulkhead doors on side of library

Installing the rubber seal is a very easy job, and ideally, your expenses would only be for the tools and product.

For the jobs requiring the input of a professional, there’ll be additional labor costs which will depend on the type of job being done. 

On average, replacing a wooden or steel bulkhead door would cost between $500 and $1,600. Replacing a fiberglass door will cost slightly more, ranging from $1,000 to $2,000.

In Closing

Water can enter your basement through gaps in your bulkhead and this can only be solved by sealing with a rubber sealant. Sometimes cracks appear in the foundation which is sealed using a concrete sealant. In the worst-case scenario, the bulkhead door may have to be replaced.

There are many ways of keeping your basement dry, and one of them is waterproofing the bulkhead door.

Bulkheads are almost maintenance-free, but by putting a few simple measures in place, they can last long. Have it checked a couple of times in a year, and don’t delay if there are any repairs or replacements needed.

Check out our previous posts on how to seal basement bulkhead doors and the cost of installing one:

How To Seal Basement Bulkhead Door

How Much Does It Cost To Install Bilco Basement Doors Including New Replacement?

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