Glass mineral wool insulation over insulated pipes in loft?

Hello,

I want to put more insulation in my loft, there is currently some between the joists (100-150mm or so). I have a combi boiler in the loft so hot, cold and gas pipes run over the existing insulation on top of the joists. These pipes are already lagged with foam insulation.

My question is: Can I roll 200mm thick glass mineral wool insulation directly over the pipes without risk of 'over' insulating them or causing another issue?

Many thanks - am a reasonably proficient diyer, but never used loft insulation or had a boiler in the loft before.

Cheers, Marshy.

 

Thanks for the reply Bob, Our preference was to not have the boiler in the loft, but it was cost prohibitive to move it back into the kitchen where it was originally. I may just insulate over rooms and leave a space where the pipes are (it's only a run about 40cm wide and a couple of meters long. I suppose an alternative may be to insulate at rafter height rather than joist height - keeping heat in the roof space (and building) at least.

Other than the heating engineer once a year, I'm the only person who goes in the loft so I'm not too worried about hiding the pipes from view.

Thanks again for your help, Marshy