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.




Housing - New Build: What acoustic board product to use for extra sound proofing of new timber floor?

Bottom of Page

1 to 13 of 13

  1.  
  1.  
    I have a new TF extension and walking on the 1st floor I have the feeling there is a slight 'bounce' in my step. Probably imagining this as i know the Egger board is only 22mm in thickness. I know I still need to insulate with 100mm mineral wool (10kg/m3) and plasterboard (15mm) the ceiling but I would like to 'beef up' the floor in any case and also add to the acoustic insulation (reduce noise from TV, voices etc from downstairs). Have told my son if he wants a drum set, then he'll have to do that in the straw bale shed...

    With a plethora of acoustic board products on the market, all claiming various dB reduction values, is there any particular product people here have experience of? Of course most manufacturers don't seem to test there product the same way, so working out the best dB/£ is difficult.

    Most products have your typical foam+board product that is then bonded to the existing floor. I'm inclined to go for that rather than anything more complicated/pricey!

    I'm only needing 34sqm of boarding on top of my 22mm egger board which are supported by metal webbed joists at approx 450mm centres. Finished floor will be carpet and vinyl (bedroom / bathroom).

    Looking to spend no more than £25/sqm if possible.
    • CommentAuthorringi
    • CommentTimeApr 27th 2016
     
    Use Soundbreaker Bars (sold under many different trade name) on the ceiling with two layers of 15mm "sound reduction" plasterboard. Both are stocked by most builder merchants.

    Detailing is important, as ANY gaps will let a lot of sound pass. So overlap all the joints in the plasterboard and you need to seal the plasterboard to the walls with flexible sealant (maybe AC51) or a foam tape you compress the boards into.

    More mineral wool will not help much, as it needs some air gap (above and/or below it) to work. Therefore don't fill all the space with mineral wool, but it must fit tightly between the joists.

    Then consider adding the overlay boards later if you need more sound reduction. they mostly reduce the sound of food steps from above.
  3.  
    Posted By: ringiThen consider adding the overlay boards later if you need more sound reduction. they mostly reduce the sound of food steps from above.


    Thanks Ringi - I may start with the expensive option of boards first - to stop / reduce that bounce sensation which is more like reality after I did some heavy walking up there a minute ago. It would be easier also to fit them now rather than wait and see how the soundbars perfrom as my electrician is coming to do is first fix and will be drilling holes through the floor. Easier to make those holes now than me fit boards after the wiring's come up through the boards in various places.

    Those soundbars seem like a good overall solution....and should stop me hearing the MIL snoring downstairs.:bigsmile:

    Will remember to leave airgap for mineral wool also - good tip.
    • CommentAuthorringi
    • CommentTimeApr 27th 2016
     
    With the mineral wool, provided you use 100mm you will get the gap you need above or below it, just due to the size of your joists.

    Assuming the bounce is due to the size of your floor joists, "overboarding" will not help reduce it. Floor are designed with some bounce so as to use smaller joists.
    •  
      CommentAuthordjh
    • CommentTimeApr 27th 2016
     
    Posted By: kentishgreenI may start with the expensive option of boards first - to stop / reduce that bounce sensation which is more like reality after I did some heavy walking up there a minute ago.

    There should be some long crossmembers running perpendicular to the joists that are there to reduce movement and are tied to the external walls of the building. Are they there? It's easy to forget and not terribly easy to put them in after the event. But you will always feel some movement in the floor, if you go looking for it.

    Resilient bars work well. Don't forget that floor coverings, especially carpet, also reduce noise.
    •  
      CommentAuthorfostertom
    • CommentTimeApr 27th 2016
     
    If by 'bounce' you mean the joists going boing, so making the ceiling vibrate like a diaphragm, then nothing on top is going to cure that, only strengthening (stiffening) the joists. Actually such spinginess, like an old building's floor before the present mania for rigidity, is rarely in itself a cause of noise transmission.

    If (particularly if, even) the joists are plenty stiff, they can vibrate elastically at lo-frequency stimulated by footfalls above. In that case, you need more resilience not less, above - you could say more bounce. For that you need carpet and/or a specialist resilient mat and/or an isolation technique. A simple board won't do it, though large thicknesses of lo-density (pinboard) wood fibre does have some effect.
  7.  
    Posted By: djhThere should be some long crossmembers running perpendicular to the joists that are there to reduce movement and are tied to the external walls of the building. Are they there? It's easy to forget and not terribly easy to put them in after the event. But you will always feel some movement in the floor, if you go looking for it.


    There are a couple of cross members under each floor, but these don't penetrate the walls. They were put in I think to just secure the joists into place.

    Thanks for the comments F'tom - gives me something to wonder over today.
    • CommentAuthorMarkyP
    • CommentTimeApr 28th 2016 edited
     
    I think British Gypsum do a system for above joists - some brackets that sit over the joists, I think on a rubber gasket of some kind, and then some dense board that is suspended between each joist, just below the floor line. Not sure how expensive this may work out but I think you could perhaps copy the approach, using their brackets and a cheaper board like plasteboard or cement panel or even just chipboard. And you could probably come up with a cheaper way to fix the panels between joists, if their brackets are expensive. I'm considering something like this for our new intermediate floors as a way to add more sound proofing without raising the floor height.

    In the past, I've used resilient bars to ceilings and stud walls, and felt they were effective. They minimise the contact between plasterboard and joists, a second layer of plastboard is typically recommended, joints offset. I used a layer of fire grade PB and then a thinner layer of standard, rather than the sound grade stuff.
    •  
      CommentAuthorfostertom
    • CommentTimeApr 28th 2016
     
    The point of the 'rubber gasket' mentioned by MarkyP is to isolate the walking surface, vibrationally, from everything below. It's not about adding mass or stiffness to the existing floor.
    • CommentAuthorringi
    • CommentTimeApr 28th 2016 edited
     
    Posted By: fostertomThe point of the 'rubber gasket' mentioned by MarkyP is to isolate the walking surface, vibrationally, from everything below. It's not about adding mass or stiffness to the existing floor.


    The British Gypsum floor system does both, it isolates the floor from the joists, AND adds mass to the isolated floor. To stop impact sound, it is all about isolated mass. (I don't like the British Gypsum floor system as it makes installing the floor deck a lot harder and most trades people will not know hot to install it. One screw in the wrong place, and it stops working. Trying to do detailed work with no floor to stand on, does not seem like fun....)
  11.  
    We've installed the British Gypsum system and I haven't heard any complaints from the builders of it being difficult to work with (although I haven't asked if they found it easy either).

    We are still a tantalising few weeks from moving in so I unfortunately can't tell you how well it functions in practice, but can report back (although I suspect you need to know before then).
  12.  
    We used an acoustic board underfloor heating system - http://www.wundafloorheating.co.uk/downloads/F09%20Acoustic%20Fibre%20Overfloor%20Panels.pdf

    I don't have a before/after for sound comparison but if anything it added to the sense of bounce - the fibre board will compress slightly and the wooden floor above it is floating so that doesn't sit completely flat.

    We then had mineral wool between the joists. My understanding was that they were doing different things - the overlay reduces impact noise (ie the thump of a foot hitting the floor), the mineral wool reducse transmitted noise (voices/music etc).
  13.  
    Thanks for the comments on the BG system. If it's the 'GypFloor' then that's no good for me as I already have a timber deck on the existing joists (egger board) and can't remove that. So I will probably end up going for:

    overlay system (e.g. http://www.monarfloor.co.uk/products/traditonal-floating-floor-treatments/monarfloor-deck-22.aspx)
    insulation between joists with air gap
    sound bars to 'de-couple' the celing from joists.

    And not forgetting 100mm of shagpile carpet in bedroom and bathroom. Obviously.:surprised:



    Posted By: Simon StillWe used an acoustic board underfloor heating system -http://www.wundafloorheating.co.uk/downloads/F09%20Acoustic%20Fibre%20Overfloor%20Panels.pdf" rel="nofollow" >http://www.wundafloorheating.co.uk/downloads/F09%20Acoustic%20Fibre%20Overfloor%20Panels.pdf


    I was going for large rads upstairs but this could also be an option - what price did you get for per sqm without installation?

1 to 13 of 13

  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