Loft insulation - 125mm Joists

[revevs]

I’m looking to add insulation to my loft. The joists are 125mm

Is there a problem with putting 100mm between the joists, and then 170mm on top?

Will the 25mm gap be an issue? I assume the top roll will probably settle and fill the gap?

 

[Mr Chibs]

It's not a problem, lay the next layer 90º to the first layer. Ideally you should be trying to get 300mm depth up there.