Drywall gap advice

[John D v2.0]

to be honest it's proabbly a gap in your air barrier but as above the accepted standard in the uk is not a high level of air tightness. people just call it ventilation or something. you're not supposed to have air blowing behind your plasterboard and your insulation is supposed to be continuous. All this usually depends on the opinions of your builder. And he's probably seen victorian houses with no insulation and open fireplaces aplenty. If it were me I'd seal it up, might save a bit of gas and stop the draughts.

 

[tony359]

Phatboy,
Unfortunately I was able to run the ethernet cables you see in the picture through that (enlarged) gap. No sealing, I can see the bottom of the wall through the gap.

John,
I have plenty of ventilation on the outer brickwall. But then I reckon it should be sealed. Anyway, that is exactly my concern: an "intentional" ventilation which is acceptable as the rockwool is preventing too much cold air to get through the walls.

 

[phatboy]

Well they have breached fire regulations then, as there should be a continuous seal near the top.

The proper fix from here is to use fire-retardant expanding foam along the gap, no need to push it in far.

 

[tony359]

Good point, a fire would escape through the void and the gap and reach the roof. Thanks Phatboy

 

[John D v2.0]

I'm not sure a normal room to roof void ceiling is intended to be a fire barrier. It's only if you have steel beans in there you'll need specific fire protection ie double boarded. The other one is if is a habitable room up there.

 

[noseall]

what is your point?

Plaster seals gaps. I can't work out whether you are being obtuse or thick.

 

[tony359]

I got that. But still fail to understand where you are going.

Maybe I am a little slow but you are certantly very rude.