Question Garage conversion advice

Discussion in 'Home Cinema Building DIY' started by maverick177uk, Apr 17, 2018.


    1. maverick177uk

      maverick177uk
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      Seem to be hitting a few problems with my conversion in the planning stages, I only need building control and they’ve been very helpful however I’m after some advice.
      My roof beams run parallel to the garage door (which is staying in place), so when I insulate the roof I have to leave a 50mm air gap, how can get airflow across these beams to the outside world, it seems I’d have to drill holes through all the beams (reducing integrity) to a few vents at the front of the garage.
      I have a gas supply/meter in the garage, (fitted after a gas leak) now apparently this cannot be in the room, I’ve complained to the gas people as I specifically told them what I was going to do and they said it would be fine. This could potentially stop,the conversion in its tracks, however the alternative is to put up a stud wall about 1m into the garage, effectively splitting the garage. So my next question.
      Would a stud wall with insulation be suffiecient for this, plaster boarded on both sides? I could use that space as storage (wife would be happy).
       
    2. Peter Parker

      Peter Parker
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      I'm not a builder, but just having a few thoughts.

      When you say the beams run parallel, do you mean they run across the garage from side to side and not front to back? If so, do the roof beams extend beyond the garage walls and have external soffits? You could put vents into the soffits on both sides so there will be some flow across that would be common to all the beams. You shouldn't have to drill through all the beams to achieve that.

      I would think the stud wall would be fine. I have a gas and electric meter in my kitchen and it's never been queried, even when I had smart meters fitted, so not sure why it's a problem. Can't it just be hidden within a cupboard? What did building control say about it? There are some regs about what happens with gas leaks and pipework IIRC so maybe that has something to do with it?
       
    3. maverick177uk

      maverick177uk
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      Hi the beams run parallel but they go into our house and next doors garage so no soffits to do that. As for the gas, building control asked me to contact the gas people, they’ve said if the meter is in a room it’s at risk, it needs to be on the outside of the house as all new builds have them these days, of course this wouldn’t have been a problem if the original was still under the stairs. As for pipe work if I wrap it with electric insulation tape and then dab over it to completely seal it when when plasterboarding, this prevents a leak filling any void in the house. So if I just created a storage bit at the front that would be ok I think.
      I think it’s like everything with regulations, they change day to day and they can be bloody annoying.
       
    4. Peter Parker

      Peter Parker
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      Can the roof be made like a 'warm deck' which I think is where they have the insulation at the top of the joist and rely on warmth from the room sitting in the gap between the plasterboard ceiling underside of the insulation, so keeping the joists warm and preventing condensation. At least I think that's how it's supposed to work. I don't think that method needs any ventilation. You just have to make sure it's isolated from the other method.

      Most gas meters are inside the house and your place isn't a new build, so surely it's not a retrospective requirement?

      I'm not sure, but I think in some circumstances (like running through a wall) gas pipes have to be enclosed in another pipe or container so if there is a gas leak it will not leak into the room, but into a ventilated space. Don't know if that has anything to do with it, but most gas pipes run around a house to gas fires, hobs or a boiler and they're not enclosed. All seems a bit odd to me. As the BCO said, might be an idea to talk to the Gas people as they should know the regs.
       
    5. maverick177uk

      maverick177uk
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      In regard the warm deck this was discussed but I have a flat new rubber roof this would I think necessitate lifting off wouldn’t it?
      In regards the gas I thought the same in that many houses have a gas meter in a room I can’t see how this is any different, I don’t think it affects building regs so I might just wing it and tell them gas board says it’s ok
       
    6. Peter Parker

      Peter Parker
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      I was thinking you could fit the insulation from within the garage so you don't have to lift the roof, but I can see that would allow cold bridging via the joists (which already exists anyway). It's not quite the same as the insulation usually sits on top of the joists in which case you're right about that, so not really viable unless you can say that cold bridging occurs with wither method.

      The thing with the gas meter is you're changing the garage into a living space so they want you to move the meter, yet whenever someone moves into an older house they don't expect them to move the meter. Sounds contradictory to me. It also doesn't seem to worry about the gas pipework that is internal to all houses that uses them, and a boiler, hob or oven can leak just like a meter can, the only difference being (I think) is that the meter should be inspected once a year. Many water boards will want to fit a water meter when a new occupation occurs so why not a gas meter which it seems is a safety concern? If it was that dangerous the gas board would be doing it as a compulsory measure where possible.

      My current house had a gas boiler in a cupboard in a bedroom when I bought it. That makes a gas meter in the house sound like a much better option yet nothing was said about the boiler.
       
    7. Peter Parker

      Peter Parker
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      I just did a quick google and there are lots of instances of gas meters being moved external. One of the things mentioned internal gas pipes must all be metal and not plastic due to the possibility of melting if a fire occurs.

      It also does look like it's down to the gas operator as to where it should go etc like you say.

      Found this pdf - don't know if it's current but it seems to say having the meter internal is OK, with some stipulations:

      https://www.gtc-uk.co.uk/docs/default-source/gas---house-builders/gtc-gas-technical-guidelines1.pdf
       
      Last edited: Apr 17, 2018
    8. john01707

      john01707
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      I did a double garage conversion at my own home from garage to cinema, the gas and electric meters were in the garage and i had them both placed on the external wall outside the garage. I then relocated the boiler from the kitchen to the last 3 feet i had left of the garage after i built a wall internally to form part of the cinema. All the external pipework conecting the meter to the boiler is in copper. This has been signed off and has a certificate of safe installation. air flow to the space above the cinema ceiling is via vents in the soffit which if you dont have are very easy to fit.
       
    9. maverick177uk

      maverick177uk
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      All the pipe work internally is copper, reading that PDF it seems that it should be ok in the garage as converting to a room it will be ventilated (more than the old one under the stairs), it will also be accessible for inspection and isolation if needed. I don’t know if building regs apply to the gas as the inspector seemed unsure, so maybe it’s an area they don’t cover and I can just build the room with it in.
      As for ventilation in the soffits I can’t do that as both walls are connnected on the length of them, one to our house and one to next doors garage. The only way to ventilate would be at the front over the garage door, which as I said earlier the beams are running the wrong way to allow the airflow. However the garage is part of an old extension the bit behind it is a dining room, so it git me thinking how they’ve ventilated that, so when I went outside it has a vent along the back of the dining extension, but how they’ve achieved air flow I don’t know, I think it was done along time ago with different build regs.
       
    10. john01707

      john01707
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      You can get flat roof and pitched roof ventilation products at the roofing superstore, they have a range of flat roof vents made by a company called Ubbink. Going on from that as for future fresh air imput to the cinema i installed a HVAC air con system which gives full temp control with both heat and cold air as my cinema was basiclly a sealed room.
       
    11. maverick177uk

      maverick177uk
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      Cheers but I’m really wary of messing with the roof it was redone a few years ago I don’t fancy putting holes in it
       
    12. maverick177uk

      maverick177uk
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      So sorted the gas meter issue as long as it’s in an external wall inside or out it’s fine and I encase the pipe in yellow tape and dab before plasterboarding. Next to sort the roof out but I think I may have a solution as there appears to be a gap at one end of the beams which leaves a half inch gap along the the length of the roof which could be the circulation I need.
       
    13. jfinnie

      jfinnie
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      What kind of HVAC did you install?
       
    14. john01707

      john01707
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      Hi,
      It is a Mitsubishi Zen unit, you have the traditional outdoor part and the indoor unit is black so works well in the cinema. it is super quiet and very efficient. The whole thing including fitting was about £1700.
       
    15. jfinnie

      jfinnie
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      I've gone for a similar one - maybe even the same: (Mitsubishi Electric Zen MSZ-LN25VG Air Conditioning System -Onyx Black).

      I was just a little confused as you said fresh air, but these Zen units just give you cold / warm air, not fresh - which needs something to bring the air in from outside.

      Do you have a window in the room?
       
    16. john01707

      john01707
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      No i dont have any windows at all, i have ceiling mounted intake fans bringing in outside air adjacent to the air con unit which then cools or heats as req. the room itself is sealed and has a two door entrance for sound retention also.
       
    17. ufo550

      ufo550
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      I'm confused re the air con. Genuine question, do you have to provide fresh air, or would trickle air ventilation be sufficient. Or does LBC require additional ventilation for garage conversion?
       
    18. maverick177uk

      maverick177uk
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      If you have a window ventilation for the room is provided by the trickle vents in them, the ventilation in the roof is different usually soffits it air bricks help with that. As I’m not having a window for room ventilation I’m just going to put an air vent in the wall, a bit like a bathroom one but not mechanical it’s the same principle as the window
       
    19. john01707

      john01707
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      The air con unit does not "need" additional air supply, it was my choice to give the room a source of outside air. I do not have the fans on all the time but it gives you a little fresh air as apposed to recycling the air in the room. my cinema is as sealed as i could get it so a little outside air is added.
       
    20. Atomicus

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      From what I've read and been told no, background ventilation is sufficient to adhere to regs, but I think someone else has mentioned 'purge ventilation' before. I am a bit unsure on it tbh, but in the process of currently undertaking a similar garage conversion project, I've had advice from an architect and several expert builders and this hasn't been mentioned to me before. You don't NEED air con from a regulation point of view... it could be problematic though if the room has a lot of heat build up due to people sitting in there for hours, equipment chucking out heat etc. If you can't cool the room sufficiently then that heat is going to create problems, moisture, smells etc. Perhaps a decent portable dehumidifier will help in that regard though (if there is no window in the room).
       
    21. jfinnie

      jfinnie
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      More details of the fans would be great. Do you have one pulling and one pushing? Or some other way for air to get out?
       
    22. john01707

      john01707
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      Just have two pretty standard fans drawing the air in via vents in the soffit, it used to get quite warm in the especially with the heating on in winter. In fact it would get to a point where the projector would give out the temp warning, this prompted the HVAC instal to get fully controlled temperatures.
       
    23. BrynTeg

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      I will just add my little bit of advice, if you are changing anything from the garage to a cinema room and are changing maybe the garage door to a window, moving bits around, addind isowool, and ecotherm insulation etc etc make sure you get certifictate's and the like from local council busy bodies, i did all this in my last home and when it came time to move and sell on, one buyer was a nightmare asking for all of the above... I managed to sort it all out with solicitors writing some sort of cert but it cost me .. Just something to think about
       
    24. ufo550

      ufo550
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      You mean compiling with Building Regs :)

      Edit; England & Wales.
       
      Last edited: Apr 24, 2018
    25. Atomicus

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      It may vary from area to area, but what does a local Council have to do with this exactly? Unless you're undertaking work that does actually require planning permission, but a basic garage conversion generally won't. In my case I was told I could do what I wanted (they genuinely couldn't have been more disinterested to be honest), I'm just not allowed to change the appearance of the front of the house due to it being a conservation area.

      Complying with building regs is a given, but isn't that more a case of having relevant paperwork, documentation, evidence of work (Part P etc.) from relevant tradespeople, and perhaps a final inspection from the relevant person?
       
    26. maverick177uk

      maverick177uk
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      The inspectors want to make sure you use right insulation etc sand will come at various stages to check
       
    27. Atomicus

      Atomicus
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      Who are these 'inspectors' though? My council couldn't give a toss what I'm doing, and have told me as much.
       
    28. maverick177uk

      maverick177uk
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      Building control, they come down check tube done damp proof, correct insulation, ventilation to sign it off. My biggest worry was if I had a fire and it’s not signed off I don’t think insurance would be valid
       
    29. Atomicus

      Atomicus
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      Are building control part of the council then, or a separate entity? My local council is utterly useless to be honest. They charge you £30 to even ask a question, it's the most broken system I've ever encountered.
       
    30. ufo550

      ufo550
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      Ensuring that Building regulations are being complied with falls to Building Control Bodies (England & Wales), either through your local authority, or through the private sector with an approved inspector. I have no experience of the latter, but apparently you can choose either.

      I guess you won't be the cause of attention, if you do not comply with building regs, unless something goes wrong, your neighbour(s) complain, or as someone's mentioned when you come to sell your property. An extension is something that's difficult to hide, but altering an internal room is something different. My local council, are a bit particular about turning a garage into a habitable room, particular a bedroom.

      The Building Regs are actually useful in ensuring work is carried out correctly. :)
       

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