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Carpet on Walls

Discussion in 'Home Cinema Building DIY' started by JEDIBLADE, Jan 6, 2003.

  1. JEDIBLADE

    JEDIBLADE
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    I'm setting up a new dedicated home cinema room and have read about putting carpet (or carpet tiles) on the wall at the bottom to deaden the effect of standing waves. Has anybody got any experience of this is it worth it ? The walls are standard brezze block covered with plaster.
     
  2. Chris Bellamy

    Chris Bellamy
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    one problem with carpet is the absorbtion of sound increases as the frequency increases (according to the Master Handbook of Acoustics), so you get a disproportionately dead high end if there is a lot of carpet around. Carpet will do nothing at all for real bass (ie: <150Hz), although I suppose effects on the higher harmonics may change the perceived bass quality.

    Having said all that, many people here have used black carpet on the walls to deaden sound reflections as well as reduce light scatter, and are very happy with the before-after comparison.
    HTH

    Chris
     
  3. Gary Lightfoot

    Gary Lightfoot
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    For multi channel surround, your front wall should be dead/absorbtive, and the remaining side and rear walls should be dead below ear height, and live/reflective above.

    I used thick wallpaper paste to stick a black carpet to my screen wall, and dark grey to the lower half of my side walls. The rear and top half of the side walls were just painted wallpaper, but the chairs in front of the rear wall have the same effect as carpet.

    Ideally you would use accoustic battening covered with Gothic of Maine acoustically transparent material, but that method isn't the cheapest or easiest IMHO.

    As I was doing my loft, I was able to see how the acoustics were changing as I added carpet each time. It definately improved the room acoustics in my case.

    Pics on my home page if you're interested.

    Gary.
     
  4. ReTrO

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    Gary: Have you used carpet tiles?
     
  5. Gary Lightfoot

    Gary Lightfoot
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    Hi Retro,

    No, I didn't use carpet tiles, just some ordinary foam backed stuff from Allied Carpets fro the side wall carpeting, and some cheap black carpet from Carpet Right for the screen wall.

    Using thick wallpaper paste meant that it went up quite easily, and can be removed with a steamer if it has to come down at any time.

    Carpet tiles will probably be OK for flat walls, but the top part of the side walls in my loft meant that I had to use something that was quite flexible.

    Tiles will probably be easier to fit. I used a staple gun to staple the carpet at the top so that it wouldn't move, and would give the glue a chance to set. I removed them a few days later. I was going to fit a small wooden strip to tidy it up, but I haven't bothered yet, as it looks OK as it is.

    Gary.
     
  6. rob j

    rob j
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    Hi Gary

    - looked at your loft conversion pics and I found them pretty impressive!

    I've given serious consideration at making use of my loft space and turning it into a HC. I almost gave up on the idea untill I saw what a great job you've done - it's given me hope!:)

    The size that i've got to work with is pretty much identical to yours.

    I'd be very grateful if you could give me some info on a few things if you don't mind me asking!

    What was the rough cost of the conversion excluding AV equipment? was it reasonable? - I plan on doing nearly all of the graft myself am curious as to what this would cost.

    The thing is that my chimney goes right up through the centre of my loft and so also need to get the builders in to dismantle it which I know will add major £'s to the project! At the moment I want to budget just for the conversion.

    Any help you could give me would be greatly appreciated!

    Thanks!
     
  7. Gary Lightfoot

    Gary Lightfoot
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    Hi Rob,

    glad you liked the conversion. :)

    As I did all the work myself, it wasn't too expensive - well under £1000 including getting someone to fit an escape window (the most expensive bit). It was over two years ago now, but I'll try to remember as best I can.

    I had already done the flooring using the loft flooring packs of 3 tongue and grooved boards after strengthening the the existing joists - the house uses 6" x 2" flooring, but the loft was 4" x 2". I had only done that for better storage purposes.

    When getting a projector came to mind I knew I'd need a dedicated room, so that's when I had the idea.

    The cost boils down to how much plasterboard and insulation you use really. I can't remember the cost, but I used Wickes 1140 x 455 x 50mm insulation slabs, cut to fit into the 4" roof joists - you have to leave a 2" air gap between the insulation and roof felt/tiles for ventilation.

    I then fitted a vapour barrier and 1/2inch plasterboard up to a height of around 7' where I then made a small ceiling for lighting (approx 24" - 30" wide IIRC). I think I used around 18 sheets for the roof joists, ceiling and small 'walls' that were about 14" high.

    I kept the chimney, all I did was give it a good clean-up and sealed with builders pva glue mixed in water, then filled the depth of the chimney either side with insulation, then fitted two layers of plasterboard over that to make a flat wall - I had to make a frame for the edges of the board to fix to where it came up to the roof plasterboard..

    To soundproof the rear wall I made a stud wall and used Wickes 30mm high density slabs and two layers of plasterboard.

    Not sure how many sheets of plasterboard I used for that - maybe another 12-14. I reinforced the purlin supports by adding another 4 x 2 to each one.

    The side walls were made from 8' x 2' tongue and groove boarding - from either Wickes or B&Q. It wasn't very expensive.

    I used a lot of silicon sealer and decoraters caulk to fill any joins at edges to help with sound leakage. I did fit a vent into the ceiling, and where I still have what remains of a kitchen range chimney, I use that as an extract with a bathroom extract fan.

    I would reccommend using the plasterboard that has a silver reflective backing if your roof is south facing. I didn't and the loft gets about 3 degrees hotter than the rest of the house. it's still cooler than it used to be though.

    I had an escape window fitted for peace of mind. This was the only thing I had someone else do. I also block it off with velcro'd hardboard so that I have complete light control. I think it coat around £245 at the time.

    I would think that the plasterboard and insulation would cost less than £300, with another £100 for sealant and wood etc.

    Electrics was quite cheap as I had already ran a lighting circuit and ring main up there from when I rewired the house, and I just bought 2 double socket outlets and a remote control dimmer from Maplins. I bought a pack of three 240v halogen sunken lights from Argos. They supply enough light to give the room a nice lighting effect which can be dimmed.

    I have fitted a smoke detector in the loft which is linked to one in the stair well from the ground floor. Should the smoke detector in the house activate, it will activate the one in the loft (and vice versa). I got those from Maplins.

    Carpet underlay and gripper rods were from B&Q and I used two rolls. As the room is just for watching films in the dark, I didn't spend too much on carpet.

    I glued the carpet to the walls using a very thick mix of wallpaper paste so that it could be removed relatively easily using a steamer.

    HTH

    Gary.
     
  8. rob j

    rob j
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    Cheers Gary - your knowledge is well received!

    I was looking at the planning regulations the other day and have found out that my floor joists are 2" too short of what they need to be to be safe - D'oh!

    Now also got to put new supports in!! But it will be well worth it in the end;)

    A few more questions though -

    Doesn't it get really hot in the warmer months, seeing as the heat of the house rises to the top? With all the insulation used to prevent sound leakage, can it remain cool even with the window in place and extractor fan?

    See I was planning on just insulating the floor from sound leakage, but will it still be heard around my house if I do not put insulation slabs on the walls, & just the plaster board?

    Thanks!
     
  9. Gary Lightfoot

    Gary Lightfoot
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    Hi Rob,

    My loft floor joists were only 4 x 2, and I just cross braced them with more 4 x 2 to level up the floor area because there was already two long 4 x 2s going from each party wall across the them (the joists were front to back, these were side to side).

    Once that was done, I then added another 4" of insulation (to make 8"), and screwed down loft flooring into all the joists and at all the joins. This was just to make sure it was level and strong enough for storage. It never bowed and there are no signs of cracks etc in any of the bedrooms, and this was after 8 years.

    The 'live load' appears to be very well spread by doing this and feels very sturdy, even with 4 of us up there with a combined weight of 55 stone.

    I've been using the loft as a projector room for about 2 years now, and the seating just happens to be over a wall which divides the landing and hallway below, so it extends right down the house to the foundations. There's never any real weight over the rooms (except the front speakers which weigh 4stone each).

    To do it more correctly, you can 'sister' the existing joists by attaching 4 x 2s to make 4 x 4s or add 6 x 2s. IIRC, Some building regs are happy with that providing the insulation can't fall down if the ceiling burns out, so you can use a metal netting to support it on the joists.

    If the room is to have a bed in it, then more stringent regs apply, and it's far more involved and expensive.

    A loft shop told me that if you aren't using the room for sleeping, then many regs don't apply, such as an escape window. I fitted one just in case and have a rope ladder.

    My house is mid terrace, so that's why I soundproofed the end walls. I'm not concerned about sound leakage into the rest of my house, but the 8" of insulation combined with the flooring, underlay and carpet seem to work well.

    As for ventilation, I have a small pedestal fan for the really hot days. The room tends to be approx 3 degrees C above the rest of the house (it was 28 when the landing was 25), and I think that this could have been reduced buy using the plasterboard with a reflective backing on the south facing roof joists.

    Apart from those odd occasions, the room is fine for the rest of the year. It has never been unbearable to watch a movie up there though. The fan combined with a few bevies and popcorn make it a most enjoyable experienc. :)

    HTH

    Gary.
     
  10. rob j

    rob j
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    Thanks Again Gary - You really know your stuff:eek:

    Cheers!
     
  11. Gary Lightfoot

    Gary Lightfoot
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    I don't know about that, but I do my best to help. :)

    Gary.
     
  12. adi

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    Gary
    top looking conversion......which has now got me thinking !!
    i was considering converting my own loft into a bit of "chill-out room" for either me, the missis or me mad 9 year old to doss about in when we wanted to get out of each other's way, but have also toyed with the idea of a cinema room and seeing the quality of your job i'm even more tempted.

    ive got a couple of questions:
    1...how much headroom have you at the apex ?
    2...does the shape of the room (triangular) effect the accoustics in any strange ways
    3...the wife has got a downer on the amount of bass which travels up into the bedroom when i watch a film downstairs - how did you insulate the loft floor - and how effective is it at isolating the bass ??
    4...not really important, but do you still have a system in your living room ???

    cheers

    adi
     
  13. Gary Lightfoot

    Gary Lightfoot
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    H adi, thanks for the kind comments. :)

    1. 7ft 2" IIRC. I made a small 24" wide ceiling to fit lights in (remotely dimmable), so it could be higher if you wanted a bit more room, and a smaller ceiling.

    2. It sounds a little different to the lounge, but not in any 'strange ways' as such. : eek: The only thing I did find accousticaly, was using monopole rear speakers on the back wall for 6.1 - the sound they produced appeared to come from the front of the room (I think the sound was bouncing off of the screen). I had to use bi-poles to negate this in the end.

    3. The loft floor has 8" of rockwool insualtion, and to isolate the bass, I placed the sub on a 1ft square paving slab, and then isolated that using 2 strips of wood with rubber strips. The bass is audibaly there, but the vibrations are reduced. Using the thickest underlay under the carpet will help. I use bass shalers in the seats to give back the sensation that isolation removed. :)

    I don't think you're going to toataly remove the bass vibes because they will transmit via whatever they touch, so it'll be a tricky thing to

    4. Yes, but I rarely use it now.

    PS: I soundprofed the part walls using the stud wall/rockwool/two layers of plasterboard method, and sealed all joins with silicon rubber, so that any air/sound leakage from the room was minimised. I can elaborate more if you decide to go this route yourself.

    HTH

    Gary.:
     

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