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Loft Conversion advice needed!

Discussion in 'Home Cinema Building DIY' started by invu2day, Aug 7, 2005.

  1. invu2day

    invu2day
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    I am contemplating turning my loft into a cinema room. My loft is a 'L' shape being 9m x 10m x 5m in lengths. My first objective is to seal and insulate the roof area. I was thinking of getting in a company like www.warmroof.co.uk to sprayseal the roof area with foam but quotes of close to £5,000 are putting me off.

    If I am to go the DIY route and insulate the roof myself what do I need to do? I can attach foil backed plasterboard from wickes to the rafters but I don't know what I need between the foil back of the plasterboard and the tile in the roof.

    Any suggestions will be much appreciated. :)
     
  2. shahedz

    shahedz
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    i think Rock Wool ( im pretty sure that's the name) is what you need, you can get various different brands try Wickes
     
  3. woody67

    woody67
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    Loft conversions are relatively complex, and require careful consideration. Firstly, and most importantly is protection from fire and your means of escape in the event of fire below.

    Then there is the actual structural alterations to the existing roof, and in particular the new floor has to able to support additional load.

    Then there is ventilation to the new room, and also the roof timbers to stop them rotting. The roof space will get really warm in summer, and possiblly from your equipment too.

    There are many ways to insulate the roof, but only a few may be appropriate. More specific details of the existing roof would be required for any advice to be relevent.

    You could certainly insulate it for less than £5000.

    Your first objective though, is to sort out the stuctural floor and any additional roof components and rooflights before you think of insulating. Then access and egress. Then ventilation. Then electrical cables. Finally insulation and plasterboarding.

    Even if you are not going to seek building regulation approval, you would be wise to follow the guidance of the relevent approved documents
     
  4. Dr Diversity

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    I would not go the warmroof route. Strip the roof back to the rafters and redo (do?) the felt. It should not let in a drop of water. Also it won't fill your roof space with dodgy fumes. Spray on roofing is a cop-out, sometimes seen as a bodge by surveyors. Spend the same money on doing it properly! :)
     
  5. owey

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    We got our loft converted about 3 years ago, we got all the slates taken off and refelted with foil backed felt. Between the rafters we put polystyrene for insulation. Then the plasterboard, we also have a Velux window with a blackout blind. We had to get a new floor as well because most loft floors will not take the weight of people up there all the time, or your ceilings might start to crack with the weight?.We also had a new spindel staircase fitted, total cost was £8500, now my PJ is up there :smashin: The main thing is not to insulate it to much because in the summer its like an oven :devil: . Don't forget to put all your wires in first to hide them and make it look more like a pro job. Depending on your loft don't start cutting all the strenght out off it, or your roof will cave in :eek: .
     
  6. nicknackynoo

    nicknackynoo
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    You need a product called Kingspan which is a foil backed insulation produced in slabs.
    You need to leave a 1 inch gap between the slates and insulation to avoid condensation.
    If the rafters aren't big enough to hold the kingspan in with the gap, then simply nail battens down each rafter then attach your plasterboard.
    This will all add significantly to the roof weight and reinforcement of the joists should be made. This doesn't have to be too expensive depending on the type of roof you have. I assume you have the open truss type of roof found in older buildings because the newer 'W' shape ones would never leave you enough room for a home cinema, and these should not be cut under any circumstances.


    Good Luck!
     
  7. woody67

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    There is an insulation product which is like bubble wrap, and has a mylar silver film and is equivalent to 50mm of traditional insulation.

    It is mega expensive , but may save on other work or structural loads.

    But as I say, its usage depends on the circumstances.

    After re-reading the original post, it seems that there is no sarking felt fitted. Its absence could have implications for the method of insulating and sealing between the rafters
     
  8. thorpe

    thorpe
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    the safest way to go about it without the need for planning permission is to get a qualified respectable architect to draw up plans for a conversion and follow them

    it really is simple to do properly once u have plans to follow but its not a case of throwing flooring chipboard down over the exsisting ceiling joists and hammering plaster board to the rafters.

    to do it proper u put a suspended floor in and that is the hardest part for a proper conversion the flooring and a staircase, if u can get proper plans then get a builder to do just that the rest u can really DIY it urself. u could follow the plans for the suspended flooring urself but its heavy work and it needs to be properly done.

    as recommended the product u want is kingspan kingspan is the brand name not sure if wickes do their own version. comes as a big board u cut it with a stanly knife or saw to fit between ur rafters but as mentioned u will need to fit extra slate lat onto the exsisting rafters.

    rockwool is fine for under the flooring but it wont keep the room as cool in the summer, and the other stuff as mentioned is more expensive but it is more efficient.
     
  9. gizlaroc

    gizlaroc
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    We did a loft conversion a couple of years ago and including a hand built staircase, and with proper planning and drawings, it cost under £15k.
    We had the house valued before the conversion at £200,000 and then after at £250,000.
    So I would say get it done properly and stick it on the mortgage if you are in an area where an extra room will add more than it costs.
    The fire proof loft insulation board cost under £1000, £5000 sounds ridiculous!
     

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