How to measure thickness of the existing quilt insulation?

[JohnBishop]

Hi Gents,

My surveyor has pointed out that the loft insulation - fibreglass insulation quilt is only about 250-300mm thick but it's uneven.

I reckon since 2017 the recommendation is to use at least 350mm.

 

From a Youtuber Roger I know that for the best insulation the quilt should not be compressed but expanded.

So my pink fibreglass quilt is expanded but then how to measure the actual thickness so I can put a new layer e.g. extra 100mm?

At the moment it is between 200 and 300mm thick.

 

I red an article that from about 250mm the return on investment from more insulation is diminished.

I reckon what would be better is to get a thermal camera and identify the weak spots.

 

Thanks

Edited July 26, 2022 by JohnBishop

[Conor]

By the time you've hired a thermal camera, poked around, figured out what to do, you'd have an extra 100 or 200mm laid. I know the price has gone up, how much would it be for your loft? When I did it, it was only about £300.

[markc]

Got to agree with @Conor why complicate it. Plus, You could fit perfect roof insulation and be throwing heat and money out through windows etc. 

[PeterW]

Standard 170mm topup Roll is £24 from Wickes - average loft that is 8 rolls, and it’s as simple as start in the far

edge and just unroll as you go. 
 

https://www.wickes.co.uk/Knauf-Insulation-Space-Standard-Top-Up-170mm-Loft-Roll---6-47m²/p/109450

 

Don’t forget a decent mask, and don’t forget to leave gaps at the eaves for airflow. 
 

Finally, make sure any hot water pipes in the attic space are insulated, big slab of PIR over the hatch and then airtight strips on the edges to make sure it’s all toasty. 
 

Fit and forget, and not a piece of technology required and all done for change of £250 and a Saturday afternoon. 

[JohnMo]

It's not rocket science, you are trying to overthink it. 

 

Was in the local b&q the other day their price are the same as Wickes and they had loads of stock.

 

Just roll it out it will find its own level, plumping is great for a day or two, it will then find its own level with the help gravity.

[JohnBishop]

On 27/07/2022 at 07:55, PeterW said:

Standard 170mm topup Roll is £24 from Wickes - average loft that is 8 rolls, and it’s as simple as start in the far

edge and just unroll as you go. 
 

https://www.wickes.co.uk/Knauf-Insulation-Space-Standard-Top-Up-170mm-Loft-Roll---6-47m²/p/109450

 

Don’t forget a decent mask, and don’t forget to leave gaps at the eaves for airflow. 
 

Finally, make sure any hot water pipes in the attic space are insulated, big slab of PIR over the hatch and then airtight strips on the edges to make sure it’s all toasty. 
 

Fit and forget, and not a piece of technology required and all done for change of £250 and a Saturday afternoon. 

ok, so I just put extra 170mm over the existing a bit dusty quilt. I understand I should not put it in parallel to the existing quilt.
There is a bit of PIR on the hatch but not sure if this is enough. I could put  a bit of quilt on top anyway.

 

Yes, I have a proper mask. Having asthma otherwise I would cough my lungs out.

 

There is 42sqm of floor space.

[JohnBishop]

On 27/07/2022 at 07:45, markc said:

Got to agree with @Conor why complicate it. Plus, You could fit perfect roof insulation and be throwing heat and money out through windows etc. 

That is why I am replacing all DG glass on all the windows. I see half of them had moisture in between so the seals are gone.
I also deep clean the window frames including the gaskets.