Attic flooring advice needed

Discussion in 'Homes and gardens' started by emmo11, 2 Dec 2018.

  1. emmo11

    emmo11 New Member

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    Hi all

    I have just started to tackle insulating the attic and would also like to use some of it for storage, nothing to heavy, mainly decorations and some storage boxes.

    The current fibre glass insulation is degraded so I have laid 100mm Knauf Eko Roll on top between the joists. Next I am going lay 200mm in the opposite direction.

    I plan on partially flooring about 50sq ft but am unsure whats the best way to go about this. I was thinking of laying 6x4’s or 2x4’s across the joists and lay loft boards from B&Q on top for convince. I have seen Loft lifters in woodies and B&q but they are only 165mm and 175mm.
    I’m guessing both of these solutions are are not such a good idea because they will compress the insulation? Is it ok to compress it a small bit?

    Is there another method people use to raise the flooring 200mm so as no to compress the insulation? Any tips would be appreciated or anything else people could suggest.
     
  2. LS400

    LS400 Frequent Poster

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    Not a good idea to compress the insulation, as it expands with heat.

    50sqft might sound alot, but is a pretty small area. Id aim for a 10x10ft section if available.

    The flooring in that section will act as insulation in its self.

    Be sure to knotch out the joists with any wiring running across that will be trapped by the flooring, and mark their locations on the boards so as not to drive a securing screw through them by accident.
     
  3. Leo

    Leo Moderator

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    The reason for this is that compresses insulation is far less effective. It's all the air trapped within the firbres that gives you the insulating properties, compressing the material removes that. Fibre glass or mineral wool won't really expand with heat.

    Don't notch the joists as this will weaken them, unless you're sure they are well over-specified for the loads. While you might not be planning to put too much up there now, once the flooring is there the load can quickly add up.
     
  4. Buddyboy

    Buddyboy Frequent Poster

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    What I did was buy the loft board from B&Q and lay these on top of the existing joists. There was insulation between the joists. then what I also did was buy the insulation rolls that come up in lidl or aldi every so often. They look like silver foil bubble wrap. I stapled these to the rafters to further insulate the area (and protect it from spiders - ref. wife). Making sure to provide adequate ventilation etc. In my case I was flooring a total small extension attic, so it was feasible. If you were flooring a small part of a larger attic, it might be an idea to create plastic "walls" to section off the floored part from the rest of the attic, to provide insulation and dust protection. heavy builders plastic or similar might be an idea. I think you can get magnetic closures that can run the length of the opening.

    The idea (in my head), is to create a sort of "storage shed" in the attic.

    And as Leo said, once there is easy access, e.g. a Stire attic stairs, you will find the amount of stuff that gets stored rises exponentially.
     
  5. emmo11

    emmo11 New Member

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    Thanks for the advice so far. I could go with a 10x10ft area for storage, the attic is 52sqm. There is no wireing in the area that I want to floor. The reason I’m not flooring the whole area is to keep the cost down.

    What material should I use to raise the floor by 200mm? I’m fairly new to this diy lark.
     
  6. LS400

    LS400 Frequent Poster

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    It really isn't necessary to raise this section for flooring. If you already have insulation level with the joists, the flooring in its self acts as further insulation.
     
  7. Leo

    Leo Moderator

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    The SEAI guide might offer some insights. Few ideas here on options for getting additional insulation under loft flooring. I used the pre-insulated chipboard panels with 100mm insulation towards the end of that page.