Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

Insulation of Attic

  • 05-10-2010 10:58am
    #1
    creedp
    Registered Users, Registered Users 2 Posts: 5,858 ✭✭✭


    I have read a number of threads recently on the topic of insulating attics which have given me some cause for concern. I live in a 1930's terraced house and to increase storage I floored out the attic with plywood sheets a couple of years back. Prior to starting the work I mentioned it to a neighbour who is a retired carpenter and he told me to lay 2x1" lats across the joists so as to raise the floor above any wiring and insulation. This I did but as I only have 4" joists the insulation is proud of the joists and therefore even with 2x1's is almost level with the plywood. I think the insulations is fibreglass quilt - I'm not sure as this was installed before I purchased the house in 2003.

    My concern now is that I have read about problems with condensation due to lack of ventilation and this could cause problems down the line for the joists. Should i be concerned? Should I lift the plywood again and maybe replace the insulation with rockwool which I think is breathable and therefore installing plywood over it would not be problematic? Or as there is a gap, albeit minor in places, between the top of insulation and the plywood will it be OK?

    btw how could I tell if the current insulation is fibreglass rather than rockwool? There is a roll left over in the attic which is wraped in a sheet of brown paper but there is no brand name/specification printed on paper?

    All opinions welcome


    Thanks.


Comments

  • #2
    RKQ
    Registered Users, Registered Users 2 Posts: 2,292 ✭✭✭RKQ


    creedp wrote: »
    My concern now is that I have read about problems with condensation due to lack of ventilation and this could cause problems down the line for the joists. Should i be concerned?
    Go up into the attic and look at the ply, is the underside wet?
    If it is wet you have a condensation problem and need to carry out remedial works. Consider installing insulation foilboard between rafters, with 50mm air gap.

    If the ply,insulation & plasterboard ceiling is dry and theses no evidence of wet stains, then you don't have a problem.
    creedp wrote: »
    btw how could I tell if the current insulation is fibreglass rather than rockwool?
    Fibreglass is yellow, irritates the skin, has a fibre feel. Rockwool is geen, has a more cotton feel, isn't as irratating to your skin as fibreglass.


Advertisement