Find out how to seal large gaps in your kitchen, bathroom, basement, and other projects in the article below. We show you tips and tricks for success in a variety of situations.
Filling gaps is an important part of any home project. Sealing up cracks and gaps between surfaces protects the underlying structures from moisture and dirt. Moisture can lead to mould and mildew, and eventually rotted wood.
Sealing gaps is also important for appearance. Nicely sealed joints and transitions between materials makes for a professional look. It also helps deter insects and critters from entering your home.
So, there is every reason to use a sealant to fill these areas. But what about large gaps? This article will show you how to seal large gaps in various parts of your home using the most appropriate materials for each application.
Let’s begin with the kitchens and bathrooms, where protection from dampness and water penetration is key to a successful job.
Wet areas such as those found in the kitchen and bathroom require special protection to stop moisture from getting underneath cabinets and walls.
One of the most common types of sealants in these areas is silicone. Silicone sealants are highly waterproof and retain their flexibility and adhesion.
If you have a large gap to fill, though, running bead after bead of sealant into a gap that is much larger than the line of sealant, will not yield the best results. A better solution is to first insert a backer rod into the gap. A backer rod is simply a foam rubber strip that is placed into the gap to provide a barrier to hold the sealant in place. Backer rods come in a variety of sizes and are widely available.
Follow these easy steps:
- Cut a backer rod to the desired length.
- Insert the rod into the gap using a putty knife or similar tool. Press it in far enough that it will not show once the sealant is applied over it.
- Apply a bead of sealant into the gap using a caulking gun.
- Smooth out the sealant with a caulking tool.
- Wipe up any excess sealant immediately.
- Allow the sealant to fully dry before normal use of the area.
Another type of sealant that is very useful to seal large gaps is polyurethane sealant. Polyurethane is a great choice for sealing big gaps in concrete or other masonry surfaces, and many varieties are rated for exterior use.
Polyurethane is noted for staying flexible and can span gaps of up to 1.5 inches (38mm)—it will not sag like some other types of sealants. Its flexibility also helps prevent cracking due to expansion and contraction as temperatures change.
Here are some tips for applying polyurethane sealant:
- Use a backer rod for larger gaps as described above.
- Read the manufacturer’s instructions as different formulas may require different preparation or application techniques.
- Fill large joints from the bottom up using steady, even streams.
Another option that works quite well on metals, masonry surfaces, and many other materials is epoxy.
Epoxy is a two-part adhesive that requires mixing before use. After mixing the components, you have a limited working time before the epoxy hardens.
Epoxy bonds firmly to many materials and can span large gaps without cracking. It dries very hard and is ideal for applications where the area needs to be sanded or machined after the epoxy cures.
Follow these directions to seal large gaps in concrete or metal surfaces:
- Dispense equal amounts of the resin and hardener and mix thoroughly.
- Using a putty knife or similar tool, apply the epoxy to the gap.
- Smooth the epoxy and feather out the edges.
- Allow the epoxy to fully cure, then sand and paint it if necessary.
Have a quick repair to make? You’ll love Loctite Universal Instant Epoxy Liquid 5 Minute. This formula begins to cure in just minutes, making short work of your project.
The special syringe mixes the material as it’s dispensed, eliminating the need to mix it on another surface. You can apply it directly to the gap. Instant Epoxy will bond to wood, metal, glass, plastics, and more.