Blocking up un-used fireplace for TV bracket mounting

Discussion in 'Builders' Talk' started by tellme_why, Feb 12, 2017.

  1. tellme_why

    tellme_why Member

    Hi all,
    I found a good guide on how to block-up and un-used fire place here http://www.practicaldiy.com/general-building/chimney/chimney-blocking-up.php to start with.
    However my job has one more complication being I need to install a TV bracket and a heavy shelf on the newly constructed fire place wall by using 6 x 8mm 50 mm long screws and plugs.
    I am concern that just using normal bricks as per link above, the wall would not take the load. Because of the shelf arrangement the load is not only vertical, there will be a lateral torque force as well.

    What brick should I use for the purpose / how to fit bricks and mortar to make the fireplace opening wall (about 70x70 cm) strong and load bearing?

    Many thanks!
     
  2. Phil the Paver

    Phil the Paver Screwfix Select

    Tv going to sit low isn't it if its on the opening?
     
  3. tellme_why

    tellme_why Member

    Thanks Phil; the load issue is due to modern piece of furniture on which the telly will seat onto. It's box 1 m wide, 18 cm tall and 40 cm deep that is wall mounted by means of two custom steel plates that in turn are screwed to the wall (six screws and plugs). It's like an heavy shelf that will support the telly weight and other stuff as well, books etc. So how to build a sound brickwork that bears the load?

    I just found the following link http://www.diydoctor.org.uk/projects/fireplace2.htm that suggest to use "frame cramps".. I quote "For an average fireplace you will also need 2 “frame cramps” which are normally fixed to a door or window frame and built into the brickwork joints. These 2 however, will be plugged and screwed to the inside of the fireplace and be built into brickwork you are building". ...

    no idea what frame cramps are for..

    I guess I should use heavy bricks too...?
     
  4. Phil the Paver

    Phil the Paver Screwfix Select

    Are the side walls of the opening flat?

    If so two choices.

    Tooth out bricks and tie in New bricks. (Strongest method)


    concrete-block-walling-22-638.jpg

    Fix a furfix (wall starter) on either side.

    download.jpg


    Also use a brick without a frog or the shollowest frog you can find, solid engineering bricks would be ideal if not a bit hard to drill.
     
  5. tellme_why

    tellme_why Member

    Thanks you very much Phil!
    The fire opening is flat (see also picture attached); I would avoid to create a tooth on the opening so the second option would be easier?
    With reference to the vertical steel bar in your picture if the fire opening is 60 cm tall should the bar be approx 30 cm?
    Would you advise to use concrete blocks so they are heavy and bear more weight?

    Many thanks!
     

    Attached Files:

  6. Phil the Paver

    Phil the Paver Screwfix Select


    The bar's should be full height, in you case if you use concrete blocks you will get 3 blocks high so only 2 joints each side that need ties.
     
  7. sospan

    sospan Screwfix Select

  8. tellme_why

    tellme_why Member

    Hi,
    Do you advise to use blocks (e.g. 440x215x100) instead of bricks (215x102.5x65)?
    I was wondering whether blocks would carry more lateral forces than bricks because of larger foot print and weight...?
     
  9. sospan

    sospan Screwfix Select

    The weakest point in structures are the joints, so less joints the better - blocks. Bricks will also be a lot more time consuming.
     
  10. Phil the Paver

    Phil the Paver Screwfix Select

    Blocks will be fine as long as they are solid concrete ones (bloody heavy) :D:D:D
     
  11. sospan

    sospan Screwfix Select

    And wait about a week for the cement to set - as a minimum when the cement changes to an even colour
     
  12. tellme_why

    tellme_why Member

    thanks!
    Looking for blocks.. should I go for the 440 x 215 x 100 standard block or for 440 x 215 x 275?
    Also should it be aerated or properly dense block?
     

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