Ideas for boarding eaves of loft conversion.

[LOGIK1]

We have a loft conversion in our 1930's house and the very bottoms of the eaves have cupboards in them for storage. These are deceptively large but the problem that we have is because the house is so old there is no lining under the tiles, the motor is deteriorating and there is a good amount of dirt and dust and leafs being blown in which then gets all over anything thats stored there.

There is already insulation on the habitable part of the conversion so I'm really just wanting to board over the inside of the tiles and the insulation so I can reliably store things in there without them getting filthy.

I was thinking of using correx board which is dirt cheap (link http://www.ebay.co.uk/itm/Correx-Sh...rrugated-Plastic-White-or-Black-/151110513091)

So the question is, is this a good idea? Is there a reason why I shouldn't be considering this? I just want something to stop the dirt and leaves blowing in by covering under the tiles and to cover over the loft fiber insulation on the inside of the wall... I was going to leave at least a 5cm gap between the board and the tiles and a gap at the bottom for ventilation. Also, the mortar has been dropping off the tiles... I'm guessing this is a bad thing?

I've taken a few photos.

Thanks in advance for any help and advice!

 

[LOGIK1]

Here a photo after some aggressive hoovering

 

[leewallbank]

as long as you leave at least a 50mm ventilation gap and leave down by the soffit clear then you can use whatever you want. If you want to insulate the area then use celotex/kingspan/etc boards which will do both.