Concrete floors are arguably one of the most common subfloors today. As a result, it’s important, particularly if you’re planning a DIY installation, to ascertain the best way to fit your floor.
The first two things you need to be clear about are:
- Making sure your subfloor is sufficiently free of dampness to install your flooring without future problems lurking ahead of you.
- Whether or not you have under floor heating.
Measuring dampness levels
It’s really important when fitting your new, engineered wood flooring to an existing concrete sub floor that the sub floor is in good condition and has an appropriately low moisture content. Ideally, the moisture content should be no more than 8% and ideally less. There are various ways of checking the moisture level of your subfloor and you’ll find an article about it here. If you discover that the moisture content of your concrete sub floor is higher than it should be, you should consider factoring in an appropriate damp proof membrane, no matter which fitting method you choose. Irrespective of your moisture readings, there are two situations where a damp proof membrane should be used as standard. The first is when you’re planning to glue down your hardwood floor to the concrete sub floor and the second is when you’ve opted for a floating method of fitting. In the case of gluing the floor, a liquid damp proof membrane should be used in conjunction with a suitable adhesive.
Under floor heating and wood flooring
Engineered hardwood flooring is the only wood flooring solution we’d recommend if you have under floor heating because solid hardwood flooring isn’t sufficiently stable to stand up to the temperature fluctuations it will encounter. We recommend that engineered flooring board thickness should be no more than 18mm and that the top layer, or lamella of the engineered board should be 5mm thick or less. These are what we believe to be the maximum thicknesses for heat efficiency.
The type of heating you have will affect the fitting method you should use. Broadly speaking, if you have electric under floor heating, the floor should be fitted using the floating method of installation. Floating floors normally have an underlay that goes under the floor and it’s important with under floor heating to select the correct underlay. If you have wet under floor heating, the floor can be glued straight on to the screed.
If you don’t have under floor heating, you’ll need to select the most appropriate fitting method for your job. There are essentially three options when it comes to fitting engineered wood flooring to concrete. They are the click system, floating or glue down.
Click system engineered wood flooring
Click system engineered wood flooring boards effectively ‘snap’ together without the need for glue or nails, thanks to their unique system. When fitting click system engineered wood flooring, it’s essential to use a floating fitting method. What this means is that there’s no gluing or nailing required and that you’ll have the opportunity to lay click floors over a concrete subfloor with the addition of an appropriate underlay.
Floating installation for engineered wood flooring
A floating floor isn’t fixed to the subfloor, instead it relies on the weight of the floor itself to keep it in place. For this method, the only parts that are glued are the tongue to the groove. This way of fitting is well suited to engineered wood flooring and is popular and quick.
Glue-down installation for engineered wood flooring
Glue down as an installation method for engineered wood floors, as the name suggests, involves using a bonding agent, adhesive or glue that you put directly on to your concrete subfloor before laying your floor. If you choose this method of fitting, you need to make sure that there’s no dampness whatsoever in your subfloor. If you have any doubt about dampness, we recommend that you install a two-part epoxy damp proof membrane to make sure that none of the residual dampness rises into your new floor, causing future damage.
Other important points to remember
ü Expansion gap. It is important, irrespective of your fitting method to make sure you have allowed a 10-15mm expansion gap around your room. You should use wedges to make sure your expansion gap stays consistent.
ü Starting point. When you start to lay your boards, start in the corner of your room that’s furthest away from the door and lay the first board in the direction you want the floor to run. Make sure the tongue is facing into the centre of the room.
If you’re planning to fit an engineered wood floor over a concrete subfloor and would like some advice, why not get in touch? After all, we’re here to help.
Q: How do I ensure my concrete subfloor is suitable for fitting engineered wood flooring?
A: It’s crucial to check the moisture content of the concrete subfloor, which should ideally be no more than 8%. If the moisture level is higher, consider using a damp proof membrane. Additionally, ensure the subfloor is in good condition.
Q: Can I use solid hardwood flooring with underfloor heating?
A: No, solid hardwood flooring is not recommended for underfloor heating due to its lack of stability. Engineered hardwood flooring is the suitable choice, with a maximum board thickness of 18mm and a top layer (lamella) thickness of 5mm or less.
Q: What fitting method should I use for engineered wood flooring with underfloor heating?
A: If you have electric underfloor heating, the floating method of installation is recommended. For wet underfloor heating, the floor can be glued directly to the screed.
Q: What are the fitting options for engineered wood flooring on concrete?
A: There are three main options: click system, floating installation, and glue-down installation. Click system boards snap together without glue or nails and require a floating fitting method. Floating installation relies on the weight of the floor and involves gluing only the tongue to the groove. Glue-down installation uses adhesive directly on the concrete subfloor.
Q: Are there any important considerations during installation?
A: Two important points to remember are leaving an expansion gap of 10-15mm around the room and starting the installation in the corner furthest from the door, laying the first board in the desired direction with the tongue facing into the center of the room.