Heat retention tests of insulation boards

[Qwerty]

I spent a bit of time this morning performing the tests. I performed the test on the garage screed, then 18mm WBP, 10mm Marmox then 6mm Marmox. I chose not to use any 20mm boards as realistically most of us never use them.

To ensure continuity the water (2 pints) was boiled then left one minute (whilst walking into the garage) before temperature was checked to ensure test was fair (stage 1).
The water in the pan was left on each of the surfaces for 5 minutes, with the water temp being checked halfway through (stage 2).
After 5 mins the pan was removed and the substrate surface temp taken (stage 3).
Underside temp of substrate taken (stage 4).
Area of garage floor directly underneath where pan was present in substrate taken (stage 5).
Each substrate left stood up with both sides exposed for 5 minutes and then surface temps taken again (stage 6 for topside and stage 7 underside where pan had been sat).

Outside air temperature was 6*c. Garage floor was an even 5.8*c. All of the ply & boards read 5.8*c too which was a good start.

 

[Qwerty]

So here are the test results................






Control Test - Garage floor
Stage 1- Starting water temp - 68.5*c

Stage 2- Halfway water temp - 63.8*c

Stage 3- Substrate surface temp - 17.6*c

Stage 4- Substrate underside temp - N/A
Stage 5- Garage floor temp - N/A
Stage 6- Substrate surface temp (after 5 mins) -12.3*c

Stage 7- Substrate underside temp (after 5 mins) - N/A

 

[Qwerty]

18mm WBP ply
Stage 1- 68.8*c

Stage 2- 63.5 *c

Stage 3- 30.6*c

Stage 4- 10.0*c

Stage 5- 5.8*c

Stage 6- 7.4*c

Stage 7- 6.5*c

 

[Qwerty]

10mm Marmox board

Stage 1- 68.8*c

Stage 2- 63.2*c

Stage 3- 54.3*c

Stage 4- 12.9*c

Stage 5- 5.8*c
Stage 6- 13.0*c

Stage 7- 10.2*c

 

[Qwerty]

6mm Marmox board

Stage 1- 68.4*c

Stage 2- 63.4*c

Stage 3- 48.7*c

Stage 4- 24.6*c

Stage 5- 7.3*c

Stage 6- 9.9*c

Stage 7- 9.4*c

 

[Qwerty]

Conclusions

No science lab standard I know, but it clearly shows that the thicker the insulation boards the better!
The bare floor clearly absorbed a lot of heat rather than reflecting it back which is to be expected. The ply being so dense absorbed more heat and this transferred through it to the underside much more than either of the Marmox boards. The ply also lost its heat much faster.
The Marmox boards performed best. The 10mm board reflected back (and retained) a lot more heat than any of the others. The heat on the top of the Marmox boards could be seen by a circle. This even transferred through to the underside of the 6mm board as well as being visible as "sweating" onto the garage floor!

Out of curiosity I checked a few things 10 minutes later and found the 12mm Marmox retained the heat best (@ 8.7*c) and the 6mm was just 6.5*c.

The floor where the 6mm Marmox had been was still 6.0*c after 10 mins whereas the floor where the 10mm & ply still read 5.8*c!!

I'm continuing to use 10mm boards where I can thanks. It just makes sense! I appreciate that ply retains temperature but my tests also showed it was a massive heat sink and didn't retain it well.

Insulation boards work.....simple as that really.

 

[Qwerty]

Copied from original post last year. Easier for people to find if needs be