How to Minimise UV Sun Damage to Your Timber Flooring
Timber flooring brings warmth, elegance, and natural beauty into any home. But just like our skin, timber is sensitive to sunlight, heat, and humidity. Over time, UV exposure and temperature changes can affect the look and performance of your floors if they’re not properly protected.
Here’s what you need to know about how timber flooring reacts to sunlight and indoor heat — and how to minimize damage.
Sunlight and UV Exposure
Timber floors exposed to direct sunlight naturally change in appearance over time. UV rays and oxidisation (a natural ageing process) can:
Soften tones in some timber species
Darken colours in others
Cause gapping or cupping, where board edges sit higher than the centre
To reduce these effects:
Install curtains, blinds, or UV-treated window films to filter light.
Pay special attention to north-facing rooms, which often get the strongest sun.
Rearrange rugs and furniture occasionally so colour changes occur evenly.
Temperature and Humidity
Fluctuations in humidity and indoor temperature can cause timber to expand, shrink, swell, or gap. To keep conditions stable:
Aim for an indoor temperature of 18–25°C (and never above 35°C).
Keep relative humidity between 40–70% using dehumidifiers or ventilation systems if needed.
Avoid extremes — consistent conditions are key to reducing stress on the boards.
Air Circulation
Timber needs to “breathe.” If rooms are closed up for too long in summer, the heat build-up can be damaging. To prevent shrinkage, splitting, and cupping:
Keep the house ventilated when away, even if just a little airflow is possible.
Avoid creating “oven-like” conditions by leaving blinds drawn and windows slightly open.
Underfloor Heating and Timber Floors
Underfloor heating can be enjoyed with timber flooring — but only if it’s managed carefully:
Run the system for at least 2 weeks before installation to dry the slab.
Keep the slab temperature under 27°C (ideally 24–25°C).
Adjust temperatures gradually — no more than 1°C per day. Sudden changes can cause boards to split, shrink, or cup.
For best performance, operate the heating system consistently year-round, rather than switching it off and on seasonally. This avoids the floor absorbing excess moisture when cooled.
Protecting Your Investment
Timber flooring is an investment that lasts for decades with the right care. By controlling UV exposure, humidity, airflow, and heating, you’ll preserve both the beauty and structural integrity of your timber floors.
At Timber Flooring Specialists, we’re here to help you get the best out of your timber. Whether you need guidance on protecting existing floors or advice on installing new solid or engineered timber flooring, our experts are just a call away.
Contact us today for professional timber flooring advice and installation in Auckland.