What Lurks Beneath? How to Manage Subfloors During Installation
Published: February 21, 2023
When you prepare to update flooring in an existing home, you look at seemingly endless sets of samples to determine what to put where. New carpet in the living room? Great idea. Tile in the bathroom? That’s a no brainer. Laminate in the kitchen? Wonderful choice. You’ve mapped out all your selections and you’re ready to schedule installation.
Except you’ve left out one critical piece of the puzzle, one that can turn your entire renovation plan into a “Now what?” crisis: Your subfloors.
The basics of the basis
Think of your subfloors as the floors beneath your floors, because that’s exactly what they are. Home construction concludes with one of two possibilities down there. Typically, when you remove existing carpet, hardwoods or tile, you’ll find either a concrete slab or some form of wood-based product, such as oriented strand board, plywood or particleboard. Subfloors often rest directly on the floor joists, the structural elements that provide support.
Each form of subflooring comes with advantages and disadvantages related to functionality, durability and initial cost. For example, oriented strand board provides cost-effective durability. Plywood outlasts OSB, but it costs more and doesn’t handle heat well. Particleboard’s susceptibility to moisture offsets its inexpensive price. Concrete offers so much strength that it can function without floor joists, although it’s a porous material that provides a cold, hard feeling underfoot.
Layers, layers, layers
In many cases, an additional layer called an underlayment sets on top of the subfloor. Some flooring types include pre-attached underlayment, which raises the product price but makes for a quicker, easier installation.
What type of underlayment you have – and whether you even need one – depends on the type of finished flooring installed, including what’s there now and what you want to put there. Hardwoods and engineered planking may need a special type of plywood subflooring to provide a flat, strong, squeak-free outcome. Mortared tile may rest on cement backer boards. Laminate calls for its own specialized foam layer. Especially if you plan to replace one type of flooring with another, you may need to swap out underlayments to ensure a great installation.
What’s down there?
Until you remove your current flooring, however, you won’t really know what lurks beneath and how much prep work it will require. In fact, the work that’s involved in removal may change the prep plan. For example, tile can kick up plentiful dust when installers remove it and its existing grout. Older homes may include hardwood floors that turn out to be glued directly to floor joists.
But your current floors can give you some clues to what’s underneath them and how much work those subfloors will need. Uneven or sagging floors, cracked tile or areas that smell like moldy water damage all signal that you may be in for some labor-intensive subfloor preparation to pave the way for your new installation.
Floor-mounted heating vents can help you preview the composition of your floor, even if they can’t reveal its full condition. Pull the metal vent up and out, and you’ll see the layer “sandwich” at the raw edge of the floor. That cross section shows you the thickness of your subfloor and helps you identify any underlayment that’s there.
Why preparation equals permanence
Remember that the long durability and even the warranty of your new floor rely on the integrity of your subfloors. With those essentials in mind, the work involved to level, grind and sand your subfloors, install new underlayment and make sure you’ll have the right foundation for your new carpet, hardwoods or tile can pay off in the lasting quality of your results. Of course, not all installations require these types of preparation, but if your subfloors need attention, we’re ready to make them work.
At Kermans, we’re experts on all aspects of flooring selection, preparation and installation, so we can help you plan ahead for any hidden challenges. When you come in to select new flooring, our Kermans design consultants will be happy to talk you through all the phases of the installation process.