Loft - covering stored items in plastic

[m6mjv]

Hi - i have just insulated my loft going from 20mm of sparse insulation to 300mm. Lokoing forward to the warmth! My question this...

for the boxes and spare househld things i have up there - should i cover them with plastic...initially to keep dust free and stop the odd leak.

I am wonder if

1) covering on the top with plastic will collect condensation and thus dampen the items.
2) covering on the bottom will do the same but condense above the ceiling
3) a full wrap will do the same as the above.

please advise

many thanks and happy xmas.

Mike

 

[Gobo]

If you can lay some thin board over you new insulation and just use cardboard boxes, as long as you not going to be piling loads of heavy stuff up there then you would need to raise batten part or all of it and board over with loft board.

It shouldn't get damp up there unless you have leaks and no air circulation.

 

[mointainwalker]

Just drape plastic over because:

If you have put down a vapour barrier before putting in all the new
insulation, it will prevent moist air rising into the void and without moist
air, no condensation in the roof-space.

 

[m6mjv]

thanks for this - i have already laid the insulation. in this particular area there is existing chip board. I am laying space boards on top, then adding another layer of chipboard as per manufacturers recommedations. There is plenty of ventilation up there but a few odd small leaks - hence the covering. Just wondered if that plastic would make dampness around the boxes (some with boks and phots in) worse?

 

[mointainwalker]

Well where is this dampness going to come from ?

As said, if no moist air rising, then no condensation.

If you have small leaks, how can the plastic make it worse ?

 

[m6mjv]

But wont there be damp air rising from the house? there is no vapour membrance between the downstairs ceiling and the loft. I dont know the answer but it seems you are the previous are suggesting plastic is fine top, bottom or all over. i will go wit that.

thanks for your help and happy xmas.

 

[Chukka63]

just cover the top,it'll will be fine.

 

[mointainwalker]

Look, there MUST be a vapour barrier between the warm moist air of the house and your insulation. If there isn't at some point within the insulation the air will cool enough so that the moisture condenses and your wooly, warm stuff will go all claggy and wet.

Mineral wool has a covering of Kraft paper which is designed to be fitted with that side towards the warmth (i.e. ceiling) and that is supposed to be a vapour barrier.

I personally am not convinced by that because the cutting of the rolls is never neat enough for a good finish, so I lay down a continuous sheet of polythene, taping joints where necessary.

This answer only concerns your insulation and has nothing to do with your books etc