Does aluminium decking get hot? AliDeck perform heat test to find out and make like-for-like comparisons to timber and composite decking

A common question our customers have is; “does aluminium decking get hot?”, and we have looked at the thermal conductivity of aluminium previously to get an understanding on the science behind aluminium’s excellent heat resistance.

With summer well and truly here, we felt that it was appropriate to conduct some in-house testing to produce some indicative data to allow us to answer the question in more practical terms. And what better day to pick to perform heat testing on our decking than the hottest ever day the UK has experienced!

Does aluminium decking get hot? AliDeck perform heat test and make like-for-like comparison to timber and composite decking

We set up a simple test rig that had two 500mm lengths of aluminium decking, two of composite decking, and two of timber decking. Our plan was to site the test rig in direct sunlight and perform regular measurements throughout the day using a laser-gun infrared thermometer. With the air temperature already at 33 °C by 10am, we hoped to see some compelling results!

Put to the test, aluminium decking vs timber and composite in extreme heat conditions

Taking a baseline reading after the test rig had sat for 2 hours in a cool, shaded area in our warehouse, we moved the apparatus to our yard and exposed it to direct sunlight.

After 30 minutes, all three decking materials had increased in temperature but we were pleased to see our aluminium decking was by far the coolest. Further readings at 1, 2, and then 3 hours in direct sunlight repeated the findings; aluminium decking absolutely trounces timber and composite decking on minimising heat build up!

Does aluminium decking get hot? AliDeck perform heat test and make like-for-like comparison to timber and composite decking

At the conclusion of the test, we sat the rig in the shade in our warehouse again and took readings after 15 minutes. The aluminium decking quickly cooled from 49.3 °C to 33.9 °C, the timber decking had cooled from 56.5 °C to 35.9 °C, but the composite decking was still hot-to-the-touch, cooling from 58 °C  to 40.9 °C!

Composite decking was by far the worst performer in the testing, recording the highest temperatures at each stage of testing and remaining hot for a longer period than the other materials.

Timber recorded similarly high temperatures throughout, although it cooled quite well once in the shade. We suspect this is due to the short lengths of timber decking used in the test and that if full lengths were used that timber would be unable to cool as quickly.

Aluminium decking gets less hot than both timber and composite decking

The key finding, though, is that when exposed to direct sunlight aluminium decking gets less hot than both timber and composite decking. This is in-line with expectations based on the excellent thermal conductivity of aluminium.

The following table shows the full data captured in the test;

Material Baseline after 2 Hours in Shade After 30 Minutes in Direct Sunlight After 1 Hour in Direct Sunlight After 2 Hours in Direct Sunlight After 3 Hours in Direct Sunlight After 15 Minutes in Shade
Timber 29.7°C 53°C 52.3°C 54.8°C 56.5°C 35.9°C
Composite 29.1°C 53.7°C 54.6°C 57.5°C 58°C 40.9°C
Aluminium 28.9°C 46.4°C 44.6°C 46.3°C 49.3°C 33.9°C
Test Conditions; Ambient temperature: 35-38°C; Test date: 19th July 2022; Location: Rochester, Kent; Time at Baseline: 10:55am

While this testing is essentially “unofficial” and performed in-house, it does present us with useful indicative data to help our customers understand the ramifications of using aluminium decking.

Certainly, the testing shows that aluminium decking performs very well indeed in heat when compared to traditional decking materials, particularly so when considering that the testing day happened to be the hottest day ever recorded in the UK!

If you’d like to know more about the performance of AliDeck aluminium decking, please call the team on 01622 235 672 or email