Dormer Insulation in void below floor

[Barry Beanz]

My wife had a loft conversion installed a few years ago and it has been problematic ever since. Since I moved in, I have been trying to work my way through the issues left by the company who installed it. One big issue is the void under the dormer floor has a howling gale blowing through it. Even the rubble, including scrap 8x4 boards, half bags of plaster, old roof tiles, joist cut offs, etc, left under there, provide no insulation from the wind. I can actually see outside over the skirting board in places. When my wife approached the builders about the wind, they said it’s for ventilation. The old soffit is still there and allowing wind to enter. Should the old soffits be blocked off and should there be any insulation in this void as the dormer floor is freezing and the ceilings below are freezing? I’m not a bad diy’er but no expert on insulation, condensation, cold breaks etc

 

[DAZB]

Sounds like the builder was a bit of a rogue trader with that performance. There should be insulation between the floors and putting some in will make all the difference. Doesn't sound like you will get much joy chasing him either unless you have some kind of warranty and you are probably better getting the insulation put in yourself. Even tackling the soffit area and windproofing that will improve it and if the soffits are solid and not rotten you can clad onto them with the 9mm cover soffits and fascias.

 

[Barry Beanz]

Thanks for your reply. At the time, she said she would take them to court and the owner said he would wind up the company if she did. They’re still trading though. Good idea about the soffits..I was worried there might be some problem with condensation below the dormer floor if i blocked them up.

 

[DAZB]

What a lowlife and i would be tempted to fire off a solicitors letter if only to scare him for a while as it is probably not worth the pain of chasing him over it unless you have a really strong case and a Contract to prove he was in breach of what you agreed and the work will not be put right by him either way. The soffits are supposed to be vented to allow airflow to the roofspace behind the insulation in the rafters and under the tiles and insulating the floorspace will not hinder any of that.