MBC Cellulose/PIR?

[ADLIan]

U-vals look to be correct for brick outer and probably only slightly higher with cladding of weather or render board.

[HerbJ]

On 12/4/2017 at 10:13, Bitpipe said:

 

I think @HerbJ build used the yellow material, we were done about 6 weeks apart.

 

I attach the detail of my MBC timberframe build.  As @Bitpipe has pointed out, my build was a few weeks in September/October 2015 ahead of his build but the execution method for the airtight membrane was different and I believe was one of the last build to be completed before MBC improved their fabrication/installation execution methods to incorporate the green OSB used on his and, I believe,  later builds

My build had a 15mm OSB/Smartply inner sheath installed at site on the inside of the exterior wall double studs prior to the airtight membrane being installed. In fact, MBC did use some of the yellow membrane (AMPATEX DB90) which they brought from their previous build, but the majority of the airtight membrane installed was the white SIKA Majpell 5 membrane delivered for my build. I attach photos at various stages of build.

My roof had 22mm sarking board but no interior OSB /Smartply. Like @JSHarris and @Bitpipe, our roof insulation is just blown into the space between the outer sarking boards and the inner SIKA Majpell 5 membrane. I attach photos at various stages of the build.

MBC_Timberframe_Build_Detail.pdf

[Flyingbartman]

On ‎04‎/‎12‎/‎2017 at 08:55, Ian said:

Won't you need an extra layer of OSB or plywood with the blown cellulose option? 

 

 

Ian, I was advised by the installer 50mm PIR would be able to cope with the pressure of the cellulose, however 25mm had the risk of blowing out. Hence no allowance for additional OSB.