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  1.  
    We lifted some t&g pine floorboards to insulate beneath, and now we're burning the scrap boards for heating. Its actually a bit frightening how easy they are to light and how fast and hot they burn, they are dry with lots of resin. I don't like to imagine how the floor would go up in a house fire.

    It seems odd that plaster wall and ceilings linings have a certain ignition resistance, but not floors.

    Does anyone understand this, are there fire safe alternatives?
  2.  
    Posted By: WillInAberdeenare there fire safe alternatives?

    Solid concrete or beam and block
  3.  
    Thanks! Anything that could be laid instead of floorboards on existing upstairs floor joists?
    • CommentAuthorgyrogear
    • CommentTimeMar 18th 2017
     
    how about a reinforced lightweight concrete screed, well tied into the walls...

    gg
  4.  
    Posted By: gyrogearhow about a reinforced lightweight concrete screed, well tied into the walls...

    I would be very surprised if joists designed for floor boards would take the weight of a reinforced screed and leave any load bearing capacity for anything else in the room!

    However you can get fire retardant chipboard in thicknesses suitable for flooring.
    •  
      CommentAuthordjh
    • CommentTimeMar 18th 2017
     
    There are Screed Board products for acoustic isolation designed for installation above timber joists that I suppose are not inflammable but their data sheets don't seem to mention that anywhere.

    I suppose that experience shows that floors don't burn when heated by a fire above them whereas they do when the fire is below. At least for enough time for people to escape.
    • CommentAuthorowlman
    • CommentTimeMar 18th 2017
     
    Fermacell do FR flooring.
    • CommentAuthorringi
    • CommentTimeMar 18th 2017
     
    Try putting a burning bit of wood on top of some your old pine floorboards laid flat outside of a stove. (E.g on a paving stone) I think you will find it takes some time for them to catch on fire, and the fire tends to not to spread fast from one board to the next one.

    The hot gases that burn in a fire given off form the heated wood in the fire tends to raise up….
    • CommentAuthorRick_M
    • CommentTimeMar 18th 2017
     
    In the same vein, how do different wall finishes compare? E.g. skimmed, taped, wallpapered?
    • CommentAuthorgyrogear
    • CommentTimeMar 18th 2017
     
    Posted By: Peter_in_HungaryI would be very surprised if joists designed for floor boards would take the weight of a reinforced screed


    well our old house had one, no pbs !

    gg
    •  
      CommentAuthordjh
    • CommentTimeMar 18th 2017
     
    Posted By: gyrogear
    Posted By: Peter_in_HungaryI would be very surprised if joists designed for floor boards would take the weight of a reinforced screed

    well our old house had one, no pbs !

    What type of reinforcement did it have?
  5.  
    Posted By: gyrogear
    Posted By: Peter_in_HungaryI would be very surprised if joists designed for floor boards would take the weight of a reinforced screed


    well our old house had one, no pbs !

    My schedule 6 table 1 for joists stops at 97,65kg/m2 dead load excluding the joist. At 2500kg/m3 makes a 5cm screed weigh about 125kg/m2- At 5cm thick this is close to ferroconcrete of the sort used to build boats and tanks etc, i.e. a specialist job and even then it is off the end the normal tables. (My tables are a bit dated but I don't suppose wood has increased in strength in the intervening years)

    So what was the screed and what were the joists?
    • CommentAuthorcjard
    • CommentTimeMar 19th 2017 edited
     
    Notwithstanding the other comments about how you're burning your flooring by directly loading it on top of a hot fire (stack it up and light the top, see how long it takes to burn down), the simpler answer is "Because it doesn't matter".
    By the time an appreciable amount of the floor is on fire, the occupants will be well dead from smoke inhalation. Forget paying a premium for fire retardant flooring, invest in a full house fire alarm system and get the people out, sod the building; that's the insurance company's problem
    • CommentAuthorgyrogear
    • CommentTimeMar 19th 2017 edited
     
    Posted By: djhWhat type of reinforcement did it have?


    Could not know, because it was there for 50-odd years maybe, and we did not change it during our occupancy.
    From seeing similar floors, the reinforcement would not be bars, but rather heavy-gauge wire mesh, perhaps 4 mm on a 10 x 12 cm grid, for example.

    Posted By: Peter_in_HungarySo what was the screed and what were the joists?


    Idem - I assume it was cement, about 6 cm thick, tiled over (kitchen floor).
    (Edited : in fact, writing this, I remember I drilled a pilot hole through the bare ceiling, and it measured as 7 cms total thickness).

    The joists including original (pine?) floorboarding were visible in ceiling of lower floor -
    from memory, joists would be perhaps 20 x 7 cms on (about) 60 cm centers. T&G boards maybe 25 mm thick x 6 inches wide.

    Because of old water damage, Inspector told me to rip out the floorboards and leave the joists, which I duly did.

    The floor area would be about 7 x 4 meters, with joists lenghtwise, so around 7 joists if I remember right.

    Given the thick walls (old property...) I suspect / would imagine that the edges of the slab (full perimeter) would be well connected in to the stonework.

    Now remembering that the floor did have a certain "harmonic" ring to it...

    The house sold with no problems at all (4 yrs ago).

    gg
    •  
      CommentAuthorfostertom
    • CommentTimeMar 20th 2017
     
    cjard is right - in UK at least smoke is recognised as by far the biggest risk to human safety/life, preserving the building is not the aim, and fire regs are built around
    a) stopping smoke spread, and
    b) ensuring enough time (and routes) to get people out.

    In UK, preserving the building is only regulated inasmuch as it might affect the building and people next door. Other places, that may be different?
    • CommentAuthorringi
    • CommentTimeMar 20th 2017
     
    A spinker system is the best method of preserving a building if you get a fire, but we don't get enough large fires for insurance companies to require them.

    However most fires only create localized damaged if they are in a room with a correctly fitted and maintained FD30s(ac), often the wooden floor does not even need replacing as the fire has burned out before it gets past the carpets.

    (In some countries the fire fighters are paid for by the insurance company and will only put out a fire if there is a person or other building at risk, unless you have kept your insurance payments up.)
    •  
      CommentAuthordjh
    • CommentTimeMar 20th 2017
     
    Posted By: ringiA spinker system is the best method of preserving a building if you get a fire, but we don't get enough large fires for insurance companies to require them.

    Aren't sprinklers a legal requirement in Wales for all new builds?
  6.  
    ''Aren't sprinklers a legal requirement in Wales for all new builds?''

    And (according to a client) conversions too.
    •  
      CommentAuthorfostertom
    • CommentTimeMar 20th 2017
     
    Water mist generator is a v good, economical alternative.
    •  
      CommentAuthordjh
    • CommentTimeMar 20th 2017
     
    Posted By: fostertomWater mist generator is a v good, economical alternative.

    What's the current situation with respect to regulatory approval for domestic systems in the UK, especially Wales?
    • CommentAuthorEd Davies
    • CommentTimeMar 20th 2017 edited
     
    Scottish regulations don't require fire suppression for normal houses, just high rise flats, schools, etc. Where they are required they say:

    Alternative suppression systems - there are many alternative or innovative fire suppression systems available including systems utilising domestic plumbing and water-mist systems. Verifiers should satisfy themselves that such systems have been designed and tested for use in domestic buildings and are fit for their intended purpose (see Section 0).
    Lot of mention in the more detailed parts of BS 9251: 2005.

    http://www.gov.scot/resource/buildingstandards/2013Domestic/chunks/ch03s16.html
    • CommentAuthorringi
    • CommentTimeMar 20th 2017
     
    I don't think there is a British Standard for Water mist generator yet, they also need more servicing then a simple sprinklers systems.

    sprinklers should be very cheap to install at first fix time, provided you don't need an approved company to do the work and you have enough water pressure. You also get a 35mm mains water pipe connected for the price of a 25mm.

    Yet again it is someone we don't do in England, hence it costs a lot if you wish to do it.
  7.  
    <blockquote><cite>Posted By: ringi</cite>sprinklers should be very cheap to install at first fix time, provided you don't need an approved company to do the work and you have enough water pressure. You also get a 35mm mains water pipe connected for the price of a 25mm.</blockquote>

    Specifically in regards to Wales there isn't a water company that will guarantee the water pressure, this is due to liability, so a tank or alternative is always required.
    • CommentAuthorDarylP
    • CommentTimeMar 21st 2017
     
    :cry: The situation in Wales is a shambles......!
    At the time of typing, no Water Co. will warrant/underwrite a mains fed system! This means approx. 1.5Tonnes water stored in the loft, or a tank o/s.
    Plus regular maintenance charges... the e/o costs are circa 4.5k per dwelling, another gravy train for the cowboys.
    As yet, I know of not one system that has been approved by BC in North- / Mid-Wales.
    It is a right PITA.
    :shamed:
    • CommentAuthorringi
    • CommentTimeMar 21st 2017
     
    Posted By: stevethefarmSpecifically in regards to Wales there isn't a water company that will guarantee the water pressure, this is due to liability, so a tank or alternative is always required.


    Its not, under the BS you are allowed to measure the water pressure you get and must remeasure it as part of the service every year. Therefore if you clearly have enough pressure you are OK, the issue is normally flow rate not pressure, hence the need for a larger mains water pipe.
    • CommentAuthorEd Davies
    • CommentTimeMar 21st 2017
     
    From the Scottish rules it seems that simply measuring the pressure is not enough:

    For a suppression system to be effective it is essential that there is an appropriate water supply. Therefore, designers need to discuss with Scottish Water what supply is likely to be available and what pressure can be expected. It is recognised that pressures will vary during the day, over the year and perhaps in future years. Therefore it is imperative that the system is designed on the basis of what the minimum pressure and flow is likely to be. If there is any doubt, a tank and pump arrangement should be used.
    Same page as referenced above.

    Apart from the reduced water damage, isn't it part of the idea of misting systems that they don't need such a large supply? Therefore not a larger mains water pipe, perhaps?
    • CommentAuthorringi
    • CommentTimeMar 21st 2017
     
    Yes the misting systems use much less water, but they need a pump with battery backup in the unit.

    What we are seeing is lots of regulations and guidance aim at making it so a sprinkler never fails preventing them from being installed when they would work for 99% of fires. It takes no more water pressure then most “good” showers for a sprinkler to control a fire in most domestic rooms.
    • CommentAuthorDarylP
    • CommentTimeMar 21st 2017
     
    true, but what if a fire breaks out in a terrace, 3 or 4 systems all 'fire' within the first few minutes before FB arrive?
    • CommentAuthorringi
    • CommentTimeMar 21st 2017
     
    The sprinkler will stop the fire spreading from the room it started in. A fire should never spread between terrace houses anyway if they are built according to building regs.
    •  
      CommentAuthordjh
    • CommentTimeMar 21st 2017
     
    Posted By: DarylPtrue, but what if a fire breaks out in a terrace, 3 or 4 systems all 'fire' within the first few minutes before FB arrive?

    Fires normally start in a single place, so even in a fire that eventually involved multiple dwellings, the initial demand would only be for one. One hopes that the fire brigade would be onsite before other dwellings were involved - that is one purpose of the building regs fire prevention requirements, after all. If a fire was large enough to affect multiple dwellings when it started, the behaviour of the sprinkler systems would be the last thing on anybody's mind.
   
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