Can u use losefill loftinsulation over joists & existin

[ZACCCC]

My kitchen, bathroom and box bedroom are built onto the back of roughly one half of my mid-terrace 1930(ish) street house - so they extend the house into the backyard space. So the loft space is in two parts, both of which have fibreglass roll insulation between the joists. This was put down about 30 years ago and I think it was either 100 or 150mm.

The main part of the loft (a sort of A section) is boarded out over the insulation. To increase the insulation to 270mm in this part I'm going to put down insulation boards over the boards which are already down.

The question I have is with regard to the other part of the loft space which is mainly over the bathroom and box bedroom. This part is not boarded out. Here, the floor of the loft goes a step down and there are under purlins every 450mm just before the step down, making it a very difficult area to access. What I am going to do is just pour loose-fill insulation into this space and then level it out at 170mm above the current level using a long rake. This will mean that the loose-fill insulation will completely cover the joists in that area. Is it ok to do this or are there any problems with doing it this way? Any advice welcome. Thanks.

 

[kbdiy]

The joists will be covered whatever insulation medium you use. The only comment I would make about loose-lay is that it will be difficult to prevent the loose-lay from falling into the eaves and so you may end up restricting the airflow, which is a no-no. Otherwise just spread away.

 

[ZACCCC]

Thanks mate. The only reason I was concerned was that what I've read about it said you should lay in between the joists so I thought there might be a problem just putting a load of loose-fill over everything including the joists but you've now alleviated my concerns. Appreciate your help, thanks.

 

[ZACCCC]

Sorry, I should have said also that I won't be laying the loose-fill as far as the eaves because there's a big purlin(?) going right across that part of the loft which will make it impossible to lay stuff right to the eaves, Thanks again.