Cavity wall insulation question

[5oysterman2]

What is the best way of checking whether the CWI is working as it should be? Many thanks

 

[stuart45]

What is the best way of checking whether the CWI is working as it should be? Many thanks

Thermal cameras are the best way. If used on the inside the cold spots will show up. When used outside you are looking for the hot spots.

 

[Harry Bloomfield]

Thermal cameras are the best way.

Some energy companies, loan out such equipment. Octopus do, but there is quite a waiting list I heard.

 

[stuart45]

Some energy companies, loan out such equipment. Octopus do, but there is quite a waiting list I heard.

Octopus are taking bookings for next winter 2026/2027 in the new year.

 

[5oysterman2]

Octopus are taking bookings for next winter 2026/2027 in the new year.

I am with octopus, but don't want to wait until then.

 

[5oysterman2]

Thermal cameras are the best way. If used on the inside the cold spots will show up. When used outside you are looking for the hot spots.

Had a quick look at hiring one, does it need a specific type for what i want or do they all do roughly the same thing?

 

[stuart45]

You just need a small hand held one. They just give you an image of the wall, with different colours showing the warm and cool spots on the wall. They work better when the inside temperature is a lot warmer than the external one.

 

[5oysterman2]

You just need a small hand held one. They just give you an image of the wall, with different colours showing the warm and cool spots on the wall. They work better when the inside temperature is a lot warmer than the external one.

Cheers

 

[^woody^]

A thermal image needs interpreting, and some understanding of what the image is actually indicating and what is normal.

The different colours are relative and often of minute or small temperature changes - which may be quite normal. There will be many areas where the images show different temperature zones, for various reasons. But what you are looking for is large areas of several degree differences for no obvious reason, and not small or gradual temperature changes.

The lower the camera resolution, the less temperature zones will be shown as areas are merged into one or other colour. This can be beneficial for DIY use, as it avoids confusion and interpretation of many colours as the image shows only significant temperature changes - which is all you need to know for insulation inspection.

A higher resolution camera (as normally hired) is useful for investigating specific issues with the construction. They will show more areas of cool spots, but they can cause alarm and anxiety if the viewer does not understand the reason for such images.

The more professional imagers have better [PC] software to help interpret and analyse the image. The cheaper ones from China don't have this, so you just rely on the screen image or a jpeg.

For CWI, it's best to crank up the heating for a while on a cold afternoon and take the images from outside later when it's dark or getting dark.

Above all, you need to be careful not to discover some make believe problem that does not actuality exist, and then worry about it and how it can be remedied.