Floor insulation

[Moggaman]

Hi . I have 150mm of insulation to go on my sub floor before screed. I hear some people say that it is best to cross the insulation as in lay 50mm one way and 100mm the other way..staggering the joints. 
I presume that this is best because the first lay of 50mm can be laid adjacent to first fix plumbing pipes and then the 100mm laid over at a different angle.. 

thing is.. I have some rooms with no first fix water pipes in them, so I could just lay the 150mm boards in one hit in these sections. Is there any issue with this?

thanks

 

[Marvin]

Nothing wrong with 150mm in one go.

If you have 2 layers it's thought a good thing to stagger the joints, a bit like 2 layers of plasterboard or loft insulation.

[Russell griffiths]

I did two layers for a few reasons. 

To stagger joints

150mm is a bit stiff and if your floor has any undulations I found the thinner layers conforms to this better. 

150mm is a pain to cut as it grips the saw, thinner sheets easier to cut. 

 

[Moggaman]

On 20/11/2021 at 14:02, Russell griffiths said:

I did two layers for a few reasons. 

To stagger joints

150mm is a bit stiff and if your floor has any undulations I found the thinner layers conforms to this better. 

150mm is a pain to cut as it grips the saw, thinner sheets easier to cut. 

 

Thanks

[Moggaman]

On 20/11/2021 at 14:02, Russell griffiths said:

I did two layers for a few reasons. 

To stagger joints

150mm is a bit stiff and if your floor has any undulations I found the thinner layers conforms to this better. 

150mm is a pain to cut as it grips the saw, thinner sheets easier to cut. 

 

Thanks