Condensation in Loft - Bubblewrap insulation

pilchardthecat

A couple of weeks ago i put some extra insualtion in my loft. This is the aluminum foil/bubblewrap stuff which i stapled across the rafters as per the instructions, and taped it up with foil tape. I have standard rock wool insulation on the loft floor between the joists.

I went up in the loft today to investigate a damp patch on the bedroom ceiling, and the whole silvery ceiling is literally dripping with moisture.

What's going on here? the stuff is supposed to reduce condensation!

Is there anything i can do or do i have to rip the stuff out?

andrew-b

Rip it out...

Someone else here had the same problem recently...see their thread here:
http://forums.moneysavingexpert.com/showthread.html?t=1388751

Andy

pilchardthecat

andrew-b wrote: »

Rip it out...

Someone else here had the same problem recently...see their thread here:
http://forums.moneysavingexpert.com/showthread.html?t=1388751

Andy

Odd. I know of 2 other people who have done the same thing and aren't having problems.

However I can't leave it as it is as it's going to destroy my roof. Damn. Lots of back breaking work went into that!

fannyadams

http://www.telegraph.co.uk/property/greenproperty/4044985/How-to-cut-fuel-bills-Wrap-up-tight-for-a-frugal-New-Year.html
4 Check your loft insulation: Current government advice is to have 10in (250mm) of "loft insulation" above the top-floor bedroom ceilings. Unfortunately, this advice never specifies which type of material to use, or how to install it without creating massive condensation problems in the roof space. Many readers complain that having increased the depth of loft insulation as instructed, they now have water dripping from the sarking felt between the rafters. Also, such a depth of fibreglass or mineral-wool fibre interferes with boarding-out of the loft space to use for storage. Rigid foam board insulation (Kingspan or Celotex), on the other hand, is a more effective material, so 4in (100mm) thick sections can be cut to fit and still allow boarding-out.
However, note that increasing loft insulation levels using any type of material will result in the roof space itself becoming cooler. This will increase the risk of condensation forming on the sarking felt, roof timbers, and the undersides of the tiles or slates. Increased ventilation can help, but it is difficult to strike a balance between insulating the house below and keeping the roof space dry.
Unfortunately, the government propaganda does not explain how to deal with this conundrum.

there is also a piece about cavity wall insulation in there too.
HTH
FA