Home  5  Books  5  GBEzine  5  News  5  HelpDesk  5  Register  5  GreenBuilding.co.uk
Not signed in (Sign In)

Categories



Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
These two books are the perfect starting place to help you get to grips with one of the most vitally important aspects of our society - our homes and living environment.

PLEASE NOTE: A download link for Volume 1 will be sent to you by email and Volume 2 will be sent to you by post as a book.
Buy individually or both books together. Delivery is free!


powered by Surfing Waves




Vanilla 1.0.3 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to new Forum Visitors
 Join the forum now and benefit from discussions with thousands of other green building fans and discounts on Green Building Press publications: Apply now.

The AECB accepts no responsibility or liability for any errors or omissions in the content of this site. Views given in posts are not necessarily the views of the AECB.



Housing - Renovation: Acoustic insulation between floors in old house

Bottom of Page

1 to 7 of 7

  1.  
    • CommentAuthorreed
    • CommentTime1 day ago edited
     
    I am looking for advice for acoustically insulating a 280mm void between ground floor and first floor. I have installed internal timber stud walls with mineral wool slab insulation on the external walls of my late Victorian house, I have insulated the suspended floor downstairs and I will insulate the loft space in the bedroom above. I have lifted the floorboards with a view to sanding them and relaying them in both bedroom and lounge with no carpet above. The old ceilings are down and I have not yet installed new ceilings. I need to reduce the drum effect which will exist if I do not install some sort of acoustic insulation between the floors. I would prefer not filling the whole enormous 280mm void with insulation for cost reasons and also I am not averse to leaking some heat from the lounge (woodburner heated) to the bedroom above. Am looking at various solutions but would happily receive comments on:
    1. layer of insulation slab (Knauf RS45) next to plasterboard ceiling of lounge. Void above to the floor boards of the bedroom. What thickness slab? will the void above slab be a significant acoustic issue?
    2. thicker layer of rolls of acoustic or loft insulation. Should be cheaper but I presume less effective? What thickness?
    3. combination of solutions 1 and 2 but it seems a bit labour intensive and costly.
    4. Decouple the ceiling by laying battens on the lower side of the joists before fixing plasterboard. How much impact does decoupling have? Not my preferred option due to limited height between the ceiling and the top of my windows

    Many thanks
    •  
      CommentAuthordjh
    • CommentTime1 day ago
     
    Sounds like my ceilings ...

    1. Acoustic rockwool slabs are good. 100 mm is enough IMHO. Varied density is a good thing. And the remaining air space is good for MVHR ducts, plumbing, wires, etc etc.

    4. The other thing I would really recommend is resilient bars. The noise isolation we have is very good.

    5. But the other thing I would NOT recommend is hard floors on the first floor, and especially if not isolated from the joists. Impact noise (footsteps) is likely to be the biggest source of noise and you really need to (a) decouple the floor from the structure and (b) ideally have a soft floor covering.
    • CommentAuthorMike1
    • CommentTime1 day ago edited
     
    There are two key aspects to consider; airborne sound (e.g. voices, TV) and impact sound (e.g. walking).

    To counter airborne sound, 'pugging' would traditionally have been used - a few centimetres of sand or other available granular material to add density. Here in France various sand-earth-lime mixes were used. It can still be used in old buildings where joists are generously sized and their spacings aren't too wide (provided you stop it falling through light fitting holes and the like).

    However, since the weight of pugging isn't compatible with modern wide joist spacings if skinny plasterboard is used, mineral wool quilt is now generally used, such as Knauf Acoustic Roll (not loft insulation). I'm not sure what minimum thickness is required to meet current Building Regs, but I'd choose 100mm or more. There are also woodfibre & hemp options; I have 2 layers of 45mm hemp-based insulation in my partitions for sound deadening, for example.

    For impact sound resistance, especially without carpets and with your height constraints, I'd decouple the ceiling using resilient bars on the underside of the joists (e.g. Gypframe RB1) - make sure you fix them and the plasterboard according to the instructions so they remain resilient. If the underside of the ceiling joists are uneven then there are acoustic hangers available, though I've not used them.
    • CommentAuthorArtiglio
    • CommentTime1 day ago
     
    I’m a landlord , i’ve a block of flats i converted from an 1870’s in 1999 and a block i built in 2004. Both done to standard of the day. Both were before any testing requirement.
    The 1870’s block has an especially problematic room, bad design on my part as its a bedroom beneath a kitchen and bathroom. Other rooms have issues but nowhere near as bad.
    The conversion when done was stripped back and ceilings were 25mmplasterboard, resilient bars , 100mm r45, floorboards, hardboard overlay , underlay and carpet. When first done tenants often remarked how quiet the flats were in comparison with other older flats they’d lived in.
    As the years passed tenants became evermore noise intolerant.
    The problematic bedroom , has had a party and external wall , studded out and noise reduction materials/ systems used. The ceiling has had another hung under the existing on rubber mounts and rail system, 50mm of r45 and another 25mmof plasterboard.
    Better but still issues ( liely due to lifestyle and hours tenant above keeps).

    Have a look at soundstop.co.uk, plenty of systems to choose from.

    The 2004 and floor block, used a knauf approved system, umpteen different layers in the ceiling and floor construction. That works well, but still get issues with flanking sound , i’m told that’s a problem of using 7n concrete blocks for the build.

    However what ever you choose to do, having bare floorboards is going to make things really hard for you. The 2004 block had laminate floors in the kitchen/lounge /diner. Footfall was very,obvious. So after about 10 years at voids, it was pulled up and replaced with carpet and a cushioned vinyl for kitchen area. Made a huge difference.

    All that said you have the advantage of not having different households either side of the ceiling , so everyone will be more considerate and easierto talk to is problems arise.
    • CommentAuthorreed
    • CommentTime1 day ago edited
     
    My thanks to DJH, MIke and Artiglio for the prompt and really helpful comments and experiences you have shared. You have convinced me that I must decouple the ceiling using resilient bars (in principle an inexpensive item but it is frustrating that the transportation costs become an expensive factor especially when you live in Devon!). It seems that I should be planning 75 to 100mm of Knauf RS45 mineral wool slabs or equivalent in the void. I have not yet abandoned the stripped wooden floorboards upstairs but time will tell, and, as you say, it is only the family in the bedroom upstairs and I still have the fall back option of laying carpet / rugs if the impact noise of footsteps becomes too much to bear. The website soundstop.co.uk is indeed good. When I look closer the conclusionI reach is that the resilient bars make the big difference. All the extra membranes, cushioned fixings etc seem to add something but the expense to incremental noise reduction ratio is high and that for my situation probably not worth it. Any other comments which others may have will be gratefully received!
    As an aside, it does make me think that the traditional lathe and plaster ceilings appear to be quite effective at insulating sound presumably due to their high density.
    •  
      CommentAuthorfostertom
    • CommentTime1 day ago
     
    Skimming, I think no one's mentioned putting resilient strips under the flooring, on top of the joists
    • CommentAuthorMike1
    • CommentTime23 hours ago
     
    Posted By: fostertomI think no one's mentioned putting resilient strips under the flooring, on top of the joists
    Yes, it's worth considering. If it was between 2 apartments I'd certainly recommend it (and probably necesaary to meet current Building Regs standards anyway). However that means making the floor above floating (i.e. not screwed or nailed to the joists). If reusing floorboards, you'd therefore either need to put battens across the joists (or chipboard flooring) and fix the boards to them, which adds cost & height to the floor and needs a solution at the staircase junction.

1 to 7 of 7

  1.  
Add your comments

    Username Password
  • Format comments as
 
Back to Discussions Top of Page
   
The Ecobuilding Buzz
Site Map    |   Home    |   View Cart    |   Pressroom   |   Business   |   Links   
Logout    

© Green Building Press