Timber Frame improve insulation

kilcul123

My house is a timber frame property, built in 1997. Generally it's not the warmest house despite upgrading windows and improving attic insulation. The wall insulation is 50mm mineral fibre wool so not the best and I'm certain it is patchy in some rooms and not providing sufficient insulation. Has anyone taken on a retrofit in a similar house? I'm looking at what are my best options and I know I am limited by the fact it's timber frame. Dry lining seems to be the only real option from my research but some information from anyone with experience of this would be great.

MicktheMan

Have you had the house tested for air tightness?

Biker1

https://www.boards.ie/discussion/2058325013/timber-frame-improve-insulation

As there is only 50mm mineral fibre between the studs adding drylining will bring the dew point into the structure with the worst case scenario of rotting timbers. To do a proper job would mean removing all plasterboard and existing insulation. Then install PIR between the studs, airtight membrane, counter battens and insulated plasterboard. Not a task for the fainthearted.

kilcul123

Not yet but I've made enquiries to arrange an air tightness test and maybe thermal imaging. There are ventilation holes in the external brick work so plenty of air circulating behind the plasterboard. No doubt some of that is making its way inside

kilcul123

We've no damp issues and the timbers are fine so don't want to fix one problem and create another by just dry lining. That will be a huge job and no doubt a big cost too

kilcul123

Quick question, should the PIR board fill the study cavity? The stud is 80mm deep but can I fill this with 80mm PIR or should I allow for an air gap and fill with say 50-60mm with another 50mm in the insulated plasterboard?