How to Seal Gap Between Exterior Wall and Floor

The gap between the exterior wall and floor is a common problem many homeowners have to deal with. There are a few ways to solve this issue, but you need to know which one will work best for your home. If you’re not sure what type of sealant would be best, here’s how to choose what kind of sealant will work for your home. 

How to Seal Gap Between Exterior Wall and Floor

There are many options, from caulks or adhesives, when it comes to sealing gaps around exterior walls and floors. This article will discuss how to seal gap between exterior wall and floor in detail.

What Is Exterior Wall and Floor Gap?

The exterior wall and floor gap is a common crack or separation between exterior and interior walls. Locate it at wall-floor intersections, like first and second floors, at door openings and where moisture can gather and cause damage to the building’s structure. It is also known as “floor and wall intersection diaphragm crack.”

Exterior walls usually connect with other walls at a joint, like first and second floors or at door openings. However, this connection becomes weak over time due to the expansion and contraction of building materials and shifting soil conditions. This reason cracks, making the wall more vulnerable to water seepage and penetration of moisture within.

Step To Follow: How to Seal Gap Between Exterior Wall and Floor

Step 1

If you are doing this job yourself, remove any furniture or appliances attached to the wall. These include mounted shelves, built-in entertainment equipment, and radiator covers. Ensure overhead lights are turned off once these items have been removed.

Remove Any Furniture or Appliances Attached to the Wall

Step 2

Remove baseboard molding around the floor of your home with a pry bar. This should expose the gap that you will be sealing.

Step 3

Use a stud finder to locate all of the wall studs within the area where you are sealing. Mark these spots with masking tape to make them easy for you to see when making your cuts. Some exterior walls may have one or two studs at the top and bottom but not in the middle. This will be determined by how your home was constructed. Cut an “X” with a drywall saw at each stud location, which will allow you to cut through both the interior wall and exterior wall simultaneously.

Step 4

Using a circular saw or reciprocating saw, cut through both walls on your marked stud lines. If you are using a circular saw, measure the outer edge of the blade (where it is about 1/8″ wider than the circumference of your saw) and set your blade depth to match. Make sure to place masking tape over the area where you will be cutting so that you don’t damage any of the exterior sidings while you are cutting. If you are using a reciprocating saw, use a metal cutting blade.

Step 5

Use a chisel to pry away the cut pieces of drywall. Remove exterior wall material first, followed by interior wall material. If you are having difficulty getting behind the wall, you can use a hammer or crowbar for this task, along with the butt end of your chisel. Take care not to damage any of the wall studs as you go. 

Step 6

Insert the dryer vent hose into one of the stud cavity openings and trace around it using a utility knife. Also, measure the depth of your wall cavity, which will determine how long of a piece of flexible duct you will need to buy at your local home improvement store. Then, cut this length of flexible duct to size using a utility knife.

Step 7

Insert the end of your flexible duct into the opening in your exterior wall and secure it with self-tapping sheet metal screws. Drill a hole directly through the drywall for each screw, being careful not to drill completely through both walls so that you don’t hit any electrical wiring in the wall.

Why Is There a Gap Between Wall and Floor?

Why is there a gap between the wall and the floor in your bathroom, laundry, or kitchen? The answer is the soffit. It is a thin strip of wood or metal that covers wiring, ducts, and other infrastructure elements. Sometimes it’s visible, sometimes not so much. The protrusion from the wall ends up as a gap between floor and wall at the end of an interior wall in your home. This is particularly evident in the bathroom.

The Protrusion From the Wall Ends Up as a Gap Between Floor and Wall

Why Are Walls and Floors Not Flush? 

There are many reasons that a wall or floor might not be flush with one another. The most common reason is non-level concrete pours, but anything from poor planning to incompatible building materials can affect this relationship between floors and walls.

Should you Seal Between Exterior Wall and Floor?

It is widespread for laminate flooring installers to be asked, “should I seal between the Exterior Wall and the Floor,” with most installers responding that it isn’t necessary. There are many reasons not to go out and spend your hard-earned money on caulk or other products to seal the crack between the wall and the floor.

First and foremost, you can’t see the crack after your floor is installed. Second, the laminate flooring will expand and contract with changes in humidity and temperature, and if you caulk that joint, it will create a pressure point where the two surfaces meet.

As we all know, expansion and contraction are part of having Laminate Flooring, so why would you want to trap it in place. Finally, caulk is designed to last so many years and turn brittle over time with exposure to exterior elements.


If you’re looking for a way to seal the gap between your exterior wall and floor, what can do many things. First, you may want to investigate using mud jacking or concrete pour as methods of sealing this space. These two solutions will help ensure any moisture is kept out of your home during heavy rains or snowmelt in the winter months.

However, it’s important to know about potential risks before deciding which solution is best for you! This blog post will teach you how to seal gap between exterior wall and floor.

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