How to fix squeaky floorboards

Why does my wood flooring squeak?

A wooden floor can creak or squeak for several reasons:

• the boards themselves are shifting as the room heats and cools or the humidity level changes;

• the floorboards were installed before they dried out fully;

• an expansion gap was not left around the room during installation so the floorboards cannot move freely;

• the floorboards have lifted from the joists over time and are creaking as they bounce;

• the joists holding your floorboards aren't level.

1. Temperature and humidity variations

Wooden floors are extremely moisture sensitive – in fact, they are practically sponges! Wood swells as it absorbs moisture and contracts when it dries out. Wooden floors therefore move around as the ambient humidity level changes. As soon as the air gets too dry or too humid the floorboards will move very slightly. This small movement cannot actually be seen but will cause your floor to squeak.

Humidity is often tied to room temperature. If the temperature fluctuates significantly (overnight, for example), a hardwood floor can creak even when no one is walking on it.

2. Nailed down wooden floors

The issue of creaky floors is much less common and much more discreet in floors that have been glued down. However, practically all solid wood floors that have been nailed down will creak when walked on. This problem is particularly common with old floorboards nailed onto joists.

When you walk on these floorboards, they often curve slightly which causes a creaking noise. This is only natural since the floorboards are load-bearing components in this scenario. If you are nailing down floorboards, they need to be at least 20 mm thick to support normal household loads (i.e. footfall, appliances, etc.). The amount your floorboards creak also depends on the length of your floorboards. The longer the floorboards, the more they will bend under weight.

3. Levelling issues

If your joists are not level, this will create hollows beneath your floorboards.

If these hollows are located where two floorboards meet, there will be a spring effect every time someone walks across it and the floorboards will creak.

Firstly you'll have to correctly pinpoint the issue and the source of the problem as well as the size of the surface and number of boards affected. Depending on your diagnostic, you have a few different solutions:

1. Monitor the humidity and temperature of the room: this method applies if your home is too dry or too humid, or the temperature fluctuates a lot.

2. Apply talcum powder between the floorboards that tend to creak.

3. Fit new nails or screws to the affected boards: over time, floorboards can shift. Simply fitting new screws or nails should solve the issue.

4. Replace any warped boards and level out the underlying structure: this is the trickiest and most costly solution, and will require the most tools and time to complete.

In order to stop squeaking as much as possible, you will have to monitor the humidity level and temperature of your home. Avoid any drastic changes in temperature as far as possible.

A good range of indoor humidity ranges from about 45 to 65% with an ideal level of 50%. However, in reality this level can be difficult to maintain as humidity varies widely throughout the seasons. In winter, the air in our homes tends to dry out as we have the heating on. It may be necessary to increase humidity at this time of year.

The most effective way to control humidity in the home (provided you don't have a damp problem) is to invest in a humidifier. These devices are designed to monitor humidity and adjust levels as required.

Talcum powder is the top traditional solution for squeaky floors. Basic and cost-effective it may be, but this method is actually used by professional floor fitters! While it is a simple and efficient fix, this solution won't last very long and you will have to repeat the process as your floorboards start to creak again.

It's worth noting that most flooring manufacturers use paraffin to prevent creaking, particularly when it comes to click flooring. However, once your floor is down this solution is no longer an option and attempting to apply paraffin after installation could be dangerous. With talcum powder, there's no risk involved. Simply apply it between the floorboards making sure it falls into the gaps as much as possible. A good way to ensure it penetrates properly is to get someone heavy to walk over the boards once you've applied the talc!

If you have a floor that has been in place for a long time, you might want to check the nails or screws in the joists where the floor creaks the most. If loose, you can simply bang or screw them back in for a quick solution. If you're after a more discreet finish, you can hide the screw heads with some wood putty.

You can also carry out some repairs by replacing the old nails with some lost head nails. However, bear in mind that, once again, this solution won't last forever: eventually the floorboard will lift from the joists and start creaking again.

If your floorboards are really creaky, you might want to replace some of them and correct any levelling issues in the floor structure. However, this is a big job and will involve you pulling up all of your floorboards.

Even if you only want to replace a few warped floorboards, it's best to sand down the entire floor before varnishing, waxing or staining to ensure you get an even result. This can be an excellent solution if your floor creaks in some spots and you already plan on renovating it.

If the entire floor creaks, you might want to think about replacing the whole thing. In this case, it is essential to level out the joists – if the floor structure isn't level, the issue will only continue if you lay a new floor.