Hi All,

I have what I would have thought was a popular question but having searched the site, I can't find a thread that tackles it..

Scenario:
1990's David Wilson mock-Tudor detached; Cavity insulation installed to a questionable standard mid 2000s (judging by temp differences across wall); we've recently moved in and are looking to thermally upgrade the building; windows are pine-framed with thin double glazing in largely excellent condition.

Plans:
To add MVHR (for benefits of forced ventilation as opposed to energy-saving per se); to invite insulation contractor in to upgrade loft insulation from 100mm to 300 or 500mm (will pay for extra) before the end of CERT funding on top of ventilation ducting; considering EWI and high-performance glazing in due course - only as I work for an EWI manufacturer and my wife is not a fan of the timber cladding.

Situation:
On inspection prior to commencing MVHR ducting, I came accross the shocking lack of insulation continuity at the eaves (diagram attached) and wondered how to ensure a good level of insulation is installed while maintaining airflow and with minimum disruption.

Does anyone have any experience of tackling this problem? Any advice, gratefully received!

This is a standard problem with a standard solution, look up Eaves Ventilation Trays or Eaves Vent Trays. They are available in new build versions which fit over the rafters & refurbishment versions which are fitted from below.

David

Posted By: tonyI prefer false insulated skeiling ceilings and the above, all the insulation looks a bit thin too

problem with this in this case is the inner wall becomes a thermal bridge.

I have done many of these and I push EPS or similar down into the cavity tight into the cavity insulation, push similar into loft under loft insulation and foam the joint, trim off to 1inch below felt linefor ventilation. Problem is this can only be done from the outside but I think this is a better job.

Thanks All, I was hoping to avoid the inevitable but it looks like the guttering and facias are coming off!

No need to remove fascias or gutters.

Hi Simon, I am surprised you are citing MVHR as your first retrofitting measure. I think you need to get insulation and airtightness to a decent standard first, which doesn't seem to be the case by your description.

If the windows are still in good condition you could see, whether you can fit thicker d.g. units with energy saving glass.
You can get EWI with a render finish as well, see whether your wife might like that idea.

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