Are Bilco Basement Doors Watertight?

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A Bilco door is a convenient feature you can add to your basement. It is a trusted brand of bulkhead entrance doors in the US. With the large opening of the door, you can move furniture or walk in and out from the basement. If you worry about water intrusion, we have researched if Bilco doors are watertight.

The design of Bilco bulkhead doors allows you to create a watertight entry to the basement. Yet you will find some air gaps on the underside of the door. The door might still leak, but there are ways to tackle the issue. You can seal the foundation joints or use a weatherstripping kit to keep the door watertight.

There are more things to do so that you can ensure that no water or moisture gets inside the basement. If you do the processes correctly, you will not have to worry. Read further on how you can keep the basement dry with a watertight Bilco door.

A basement door of a new construction home, Are Bilco Basement Doors Watertight?

Will Bilco Doors Keep Water Out Of The Basement?

Bulkhead doors like Bilco are sturdy metal doors to protect basements and cellars from water seepage and damage. The doors are on a fixed and slanted, horizontal angle with steps leading down to the basement. This type of door is common for walkout basements.

A Bilco door is weathertight due to its flanged construction. The flanges shed water and prevent ice and snow build-up. Also, the sloping keeps the door dry and free from debris.

There can still be water leaking when there is rain or snow because the doors are not airtight. You will notice that there are gaps on the bottom of the door. Listed below are some causes of the leaks:

  • There are holes in the caulk/sealant
  • The sealant lacks adhesion due to wet foundation during installation
  • The caulk used is already old or expired
  • The door frame has some gaps when closed
  • The foundation is below grade, or there are bodies of water surrounding it
  • There are leaves and other debris holding water that get stuck on the door frame
  • The gutters above the basement doors are leaking

It is a headache if the problems persist. Hence, it will help you minimize damage if you take preventive measures to eliminate moisture and water.

How To Make Bilco Doors Watertight

View of cellar doors known as Bilco Doors

There are methods to prevent the leaks, as well as dirt and other debris in the basement. You can do a combination of the following:

  • Adding weatherstripping to the base of the stairs to the basement
  • Adding foam insulation on the inner side of the door
  • Caulking the foundation joints
  • Making the band joist airtight with sprayed icynene
  • Treating joints with pressurized mudsill
  • Spraying foam between the door jamb and concrete wall
  • Sealing of the concrete stairs and exposed foundation
  • Sealing the bottom step to the foundation footing and top of the concrete wall with a foam sealant

From the given ideas, it will seem challenging. But then, making the door watertight is vital if you want to avoid problems in your basement.

What Are Bilco Doors Made Of?

Open storm cellar door

Bilco offers a variety of safe and code-compliant basement doors. You can select from their range of durable doors. Below are the two major basement door series available.

The Classic series are doors made of heavy gauge steel for all-weather purposes. You can choose from a baked Sherwin Williams primer or powder coat paint finish for the door primer. The coating is weather-resistant, so you don't need to paint the door after installation.

For their Ultra series, you get a durable, corrosion-resistant, and high-density polyethylene door. This type has a simulated wood construction that matches your home exteriors. It is also good to use this door for homes in coastal areas.

No matter what series you choose, you can benefit from the doors' high quality and design. Also, you can choose from different door sizes. Continue reading to know the available Bilco door sizes to suit your needs.

What Are The Sizes Of Bilco doors?

To pick the suitable basement door size, here are the features to consider:

  • Inside and outside width and length of the areaway foundation
  • Height from the top of the areaway to the top of the opening in the basement foundation

Bilco doors offer two basic styles of basement doors. You can choose from steel doors for flat or sloped foundations under the Classic series. The available sizes are C, B, O, SL and Ultra.

For the Ultra series, the only available size is C. There are also available extension panels in 6, 12, 18, 24, or 30-inch variants.

When purchasing the door, you can also order door accessories that can include the following:

  • Extensions
  • Foundation plates
  • Keyed lock kit
  • Stair stringers (made of 14-gauge galvanized steel)
  • Weatherstrip kit

You can buy the door and the accessories online or from the local hardware.

How Do You Seal A Bilco Door?

Although the doors are weathertight, it cannot be a guarantee that your basement will stay dry.

The door primer and the sloped position helps, but only to some extent. But, the door design includes air gaps on the undersides. In this case, the cool basement air will not condensate on the undersides.

To seal the basement door, you will need to purchase the Bilco basement door weatherstrip kit.

Click here to see this door weatherstrip on Amazon.

The weatherstrip protects the bulkhead areaway. With this product, you can seal any intricate or irregular areas of the basement door. You will need tin snips or large scissors for the installation. Then follow the process below to install the product on the door:

  1. Attach the U-shaped gasket on both horizontal and vertical side flanges. When you reach the end of the flanges, trim the gasket.
  2. With the bulb-trim gasket, install them to the bottom flanges of the door. Then trim at the ends.
  3. Add the seals inside the top and bottom of the right-hand door leaf cap.

Even if you can use the kit for other steel basement door brands, this won't work for the Bilco Ultra series. You can use a polyurethane caulk for the Ultra series. The product creates a watertight seal between the concrete and door frame.

You can maintain a dry and damage-free basement when you properly seal the doors.

Can You Cover Bilco Doors?

The dingy double-door entrance to the basement

It is possible to cover a Bilco basement door. You might want to cover the door to protect it from weather elements or make it blend with the landscape.

You can be creative in concealing the basement door. Here are some ideas you can do:

  • Use an outdoor screen made from lattice or bamboo. Install the screen on either side of the door. You can also use other screen options like a pergola or free-standing trellis. For the trellis, you can grow some climbing plants on it.
  • If the basement door borders is a lawn, you can create flower beds on the sides of the door. You can plant perennials or shrubs that are tall enough to hide the door. If you have a stone or concrete patio, you can make a container garden.
  • You can transform the sloped foundation to become an outdoor lounge area. Add your outdoor furniture to keep the door out of sight.
  • If you have children who love to play near the basement door, you can designate the area on the side for toy storage or a bike rack.

When doing any of the ideas, remember that you should have nothing to obstruct the way of the basement door. You still need to maintain the functionality of the door even if you don't notice it.

In Closing

Bilco doors are weathertight but not watertight. But you can do the proper sealing of the door and the immediate parts of the basement to get rid of water. Bilco door materials can either be steel or polyethylene. Regardless of composition, the door is a good feature for basements.

If you want the basement door to be watertight, you will need to seal it. You can use the Bilco weatherstrip for the steel doors or a caulk sealant for the Ultra series. You can also show your creative side when covering the door outside your house.

After all, making your Bilco door watertight will keep your basement dry and safe.

You can read more about basements from our posts:

Does A Basement Door Count As Egress?

How To Protect Basement Windows From Snow

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