How to increase floor level

Discussion in 'Builders' Talk' started by Suzan Aydin, Dec 14, 2020.

  1. Suzan Aydin

    Suzan Aydin Member

    Hi guys,

    So just put the new joists up in the bathroom as we are redoing it, and we’ve checked that we’ll need about 12cm to be up to the floor in the hallway.

    now, with thick plywood, floor adhesive, abacus elements boards, shower tray, tile adhesive, and tiles, that’s only gonna bring us up to about 7cm tops.

    how can we bring this up a bit?

    can we add more ply?
  2. Bob Rathbone

    Bob Rathbone Screwfix Select

    Yes, more layers of ply or maybe even chipboard with the ply on top.
  3. Suzan Aydin

    Suzan Aydin Member

    Is it really bad to do that? How many stacks of ply can you realistically and structurally put on the floor without compromising any floor integrity or it being too heavy for the joists. They are 2 by 6s only going 1.47m long with a span of about 42cm
  4. I-Man

    I-Man Screwfix Select

    what sort of flooring did you have before that made up the 12cm gap? Seems very big
  5. Jord86

    Jord86 Screwfix Select

    Why didn't you set the joists down from the threshold the required flooring distance?
  6. RolandK

    RolandK Screwfix Select

    That's a big difference to make up between the levels! Why not build up the height of the new joists with battens?
  7. DIYDave.

    DIYDave. Screwfix Select

    Madness .......
    120mm to make up ? Needs the background to this - how and why ?

    Say you’ve got 20mm with heating mats, adhesive, tiles (approx), that still leaves 100mm to make up

    Plywood available from proper timber yard / building depot at 25mm thickness so that’s 4 sheets of ply ,,,,, madness (again)

    Gonna be well heavy and crazy expensive

    Lay another set of joists across originals in opposite direction

    But more details needed
  8. Suzan Aydin

    Suzan Aydin Member

    we couldn't as we wanted to drill in the middle of the brick rather than through the mortar for the anchors, we had two choices either go low or higher than the original floor
  9. Suzan Aydin

    Suzan Aydin Member

    long story short, we had to replace the old floor as it was rotten and was done badly and we could not go with the old design so we decided to go with two two bearers and and 6 joists in between, problem is we could not drill the anchors any higher as they would have gone through the mortar between the bricks and if we went even higher we would have ended up above the previous floor so we took the risk of going lower rather than higher
  10. Suzan Aydin

    Suzan Aydin Member

    the used 2x4s but slotted them to the wall, to do that they had to cut them and make them smaller... we couldn't go with that design so instead we went with the option mentioned above in my reply to DiyDave
  11. Suzan Aydin

    Suzan Aydin Member

    Correction. It’s 95mm instead of 120mm. If that helps....
  12. Jord86

    Jord86 Screwfix Select

    The third choice would have been to drill them in the correct place irrelevant whether it goes into the brick or bed, you have now created a lot more work and grief. If I was you I would undo all the fixings you have put in and use a sledgehammer or lump hammer if you can't get the swing to bump the structure up.
  13. I-Man

    I-Man Screwfix Select

    Surely you could have moved a couple of cm up or down to drill into the brick and drastically reduce your 12cm gap
  14. Suzan Aydin

    Suzan Aydin Member

    Sadly it’s a bit late for that....

    time has kinda run out.

    I had an idea but don’t know if that’s appropriate.

    it’ll get the level up properly.

    1. put 18mm ply
    2. Adhesive (bout 3mm)
    3. Q-board (like an abacus backboard) 50mm
    4. Adhesive (about 3/4mm)
    5. Put 18mm ply
    6. Tile adhesive (3mm?)
    7. Tiles 10mm

    brings us to about 105mm

    question is, is it ok to do this? Yes it’s faff and grief but no choice now...

    the shower tray is an impey that is 22mm, so thought of having that sit on the cement board (I.e the Q board) then using the plywood to get the floor flush with the shower tray. Then tank.

    is this ok?
  15. Suzan Aydin

    Suzan Aydin Member

    I meant 9.5cm gap. It was a mistake on our part but we were overthinking everything to the point of causing this issue. Does the suggestion I proposed above sound at all possible?
  16. Jord86

    Jord86 Screwfix Select

    No. Just fix new 4x2's on edge at 90degrees to the low ones and noggin the ends and middle. 4x2 finishes around 95mm, it's the least hassle.
    stevie22 and RolandK like this.
  17. Suzan Aydin

    Suzan Aydin Member

    True... we do have a bunch of 2x4s sitting here... either that or we replace the 2x6 horizontal ones with 2x8s (assuming a 2x6 ledger is allowed with 2x8 horizontals).

    Could you draw out what you mean Jord? Just something crappy in paint so I can picture what you're saying a bit better as maybe we can save our butts and go down that route... appreciate it
  18. Suzan Aydin

    Suzan Aydin Member

    Side note, if the 2x4s are laying with the 4 inch side vertically, it would come too high, so also, do you mean the 4 laying flat and the 2 facing vertically?
  19. Jord86

    Jord86 Screwfix Select

    You stated you required 95mm to be made up, I just told you how to do it, if it's too high use 3x2 instead.
  20. Suzan Aydin

    Suzan Aydin Member

    Ok so you can’t lay the 2x4s flat. Not sure where they do 2x3s but will have a look

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