Stick built wall build up

[Iceverge]

I'm not crazy about having PIR inboard of the studs. Firstly because they will be kept below the dew point for much of the year with the PIR keeping the internal heat away from them. This really limits drying for most of the year as temperature is such a large factor in evaporation. Concentrating only on the permeability of materials and ignoring the fact that a wall will readily dry inwards as well as outwards seems to be flawed logic, localised to our part of the world.

 

 

Secondly because of the large daily variations temperature on a sunny day for the timbers. Look at these two diagrams and note the location of the layer of PIR. 

 

 

Without too much digging into it I would say that the long term stability and durability of the studs would be much improved by being inside the layer of insulation with a much more consistent temperature and humidity level.

 

 

For my money something like this would be better. 

 

 

Dig into thermal bridging a little and maybe as build airtightness results to get a complete picture of what is realistically achievable with each method. 

 

 

Oh and for some reason I really want a sausage roll. Cant figure out why thats in my head.,......

 

 

 

[G and J]

16 hours ago, Iceverge said:

Oh and for some reason I really want a sausage roll. Cant figure out why thats in my head.,......

 

I built this housey on sauuuuuuu  saaaage rollllllllls… 

 

But I’m guessing I need a good rodent barrier.   
 

(With apologies to LadBaby!)

 

 

I'm really appreciative of all the inputs guys, I think I need to reflect and revisit this soon.