4 signs of a good subfloor

4 signs of a good subfloor

A good subfloor is key to getting the best performance out of your new flooring. Before you can even think about laying down your laminate flooring, vinyl flooring, LVT, or carpet, you need to check the existing subfloor is in good condition. If it isn't, any imperfections underneath, like lumps, dips, and wobbly bits, will be reflected in any flooring laid on top. In this helpful guide, you’ll learn about the different types of subfloor, how to spot a good subfloor from a bad one, and how to fix minor issues to prepare your subfloor for your new flooring (with a little help from some professional flooring experts like us, of course).

What is a subfloor?

In a nutshell, a subfloor is the surface on which a floorcovering is laid. Every floor is made up of different layers: the joists (the structural element which supports everything on top), the subfloor, the underlay (depending on the flooring type), and finally, the decorative floorcovering on top, like carpet, vinyl, or laminate.

What are the different types of subfloor?

There are lots of different types of subfloors - the main ones being wooden floorboards, screed, and concrete - all of which have their pros and cons. Which type of subfloor you have in your home will depend on many factors, such as how old your house is. You might find you have different subfloors in different rooms if your home has been extended or renovated over the years.

What does a good subfloor look like?

Before the flooring can be laid, you need to make sure your subfloor is dry, smooth, structurally sound, and free from debris. A subfloor in poor condition will need to be repaired or replaced before new flooring can be installed - this should always be done by a professional (which we can help with!). Here are four signs of a good subfloor:

  • Dry - This means completely free from moisture, not just dry to the touch. This is especially important if you've recently had a concrete or screed subfloor laid, which often takes a minimum of one day's drying time per millimetre of thickness. To test for moisture in your concrete subfloor, tape a square of polythene to it and leave it overnight. If there's condensation on the underside of the polythene, or the concrete underneath is a different colour to the rest of the subfloor, then it's not fully dry yet.
  • Smooth - To find out if your subfloor is uneven, place a 2m straight edge or spirit level on the floor. The tolerance on the undulations is 2mm, which is roughly the thickness of a £1 coin. If you can slide the £1 coin under the straight edge or spirit level, then your subfloor will require some correction by professionals before your new flooring can be laid. Sometimes all that’s needed is a self-levelling compound over the top of your existing subfloor to smooth it out (but this will need to dry before a floorcovering can be laid).
  • Structurally sound - The subfloor should be solid, stable, and able to provide support for anything placed on top. If you have a wooden subfloor, all the floorboards will need to be nailed or screwed down securely or covered with plyboard if there are too many big gaps, before any new flooring can be laid.
  • Free from debris - There should be no loose debris on the surface of the subfloor such as dirt, dust, disintegrated underlay, or old adhesive. Any big lumps of glue need to be scraped off and the subfloor should have a thorough sweep and a vacuum before the new flooring goes down (which all good fitters will do).

How can I tell if my subfloor needs to be repaired?

It can be hard to tell if your subfloor needs repairing or replacing, but if you order your new flooring from Tapi, we can assess your subfloor for you during a home visit or when we do our measurement checks. Don't worry, we won't be ripping up your existing flooring to look underneath! Phew! Instead, our surveyor will walk around to listen out for loud squeaky floorboards and to feel if the subfloor moves about or shifts. They'll also ask questions about when your house was built and whether you've recently had an extension to assess the condition and type of subfloor that's underneath. If they're still unsure, they'll ask one of our fitters to pop round and double check prior to fitting.

Another thing they’ll bear in mind is the type of floorcovering being laid on top, as that can make a difference to the amount of work that needs doing to the subfloor. Because of its thickness and flexibility, carpet can disguise small imperfections in a subfloor, whereas the same can’t be said for the more rigid laminate or luxury vinyl planks. But don’t let that influence your choice of flooring! A less than perfect subfloor can be sorted out very easily by our clever team of professional fitters.

What happens if my subfloor needs work?

We'll always aim to keep any additional works to a minimum, but should we discover your subfloor needs repairing, we can provide you with a quote. If you're happy to go ahead, we'll arrange for our fitting partners to carry out these works prior to installing your new flooring - just ask a member of Team Tapi in-store for details. We want your new floor to be the best it can possibly be - and that starts and ends with the subfloor.


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