We have some very wonky floors in a couple of our upstairs rooms. In my view, this causes a nice character feature. Ideally however, I think the bathroom will need a flat floor for tiling purposes. It's currently carpeted (I know, previous owner etc and it's pink AND goes up the side of the bath!) and we want something, well, more hygienic... So what's the process behind doing this? Assuming the beams under that floor are OK (which I'd have checked out by a professional before anything is done), I'm guessing something like thick ply gets laid on the floor to flatten it out. But, in my mind, this will cause a void between the board and the supporting beams that will need filling or the boards will become springboards. How is this achieved? Also, how do you join the boards so they don't crack? I'd love to know how it's done so if anyone could tell me, I'd be very grateful.
- Thread starter Minkeycat
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Pennyviz
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Hi Minkey
I have done this with limited success
Traditionally one used marine ply 12mm, nowadays there is backer board too. Both will create an increase in height. One can lay a double layer to stop movement on cracks. Personally I have still found movement over cracks but that was probably my fault for using too thin natural stone.
In terms of uneven joists one can pack under boards or lay 'sister' joists to even out dips etc.
Probably best to lift floorboards, see whats what, and then show to a builder.
Good luck
Penny
I have done this with limited success
Traditionally one used marine ply 12mm, nowadays there is backer board too. Both will create an increase in height. One can lay a double layer to stop movement on cracks. Personally I have still found movement over cracks but that was probably my fault for using too thin natural stone.
In terms of uneven joists one can pack under boards or lay 'sister' joists to even out dips etc.
Probably best to lift floorboards, see whats what, and then show to a builder.
Good luck
Penny
Abi Cott
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My employers bathroom fitters use 18mm ply which is pretty rigid, but might still need packing. It comes in 8 x 4 sheets. How big is the exposed floor area?
Interesting. Thank you both. The area in question is probably about 3m-ish (10ft) x 2.5m ish (8ft) so a couple of boards. The problem is that "we" want to put in a cast iron art deco skirt bath that ways something like 350lbs when empty. This is why I'm getting the beams checked by a structural type. I think packing between beam and board will be necessary - I'd be interested to know how this is done. If the bath's too heavy we'll change tack which will be a shame because the iron one is waiting in the garage to go in. However, we'll see...
Thanks for advice so far.
Thanks for advice so far.
plasticpigeon
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I took the floor boards up which means that 18mm ply can be laid straight on the joists. My floor boards were in such a state it was a no brainer for me, if yours are nice, then it would be good to leave them. You can level the bath without necessarily levelling the floor, which might be a nice opion and the one I took. Also I laid lino type stuff ( Ii think it was actually vinyl) on the ply. Although I like tiles, I'm not sure I like tiling a bathroom floor as it seems a bit permanent and awkward to deal with if repairs need to be made. I think adding sister joists screwed to the originals but with their upper surface level is the way to go if you want the floor level and you are happy to take the boards up. If you wish to leave the boards it will be a bit trickier as I suppose wedge shaped packers will be needed.
Cubist
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Hi Minkey,
A builder would use what are called 'firrings' to adjust the height of each joist to provide a consistent level across the floor. These are strips of suitable construction grade timber about the same width as the original joists and are tapered to form a long wedge shape the length of each joist. The trick is to find the highest spot in the room and from this to measure the height difference at each end of 'each' joist to work out the dimensions of each wedge needed to correct the level. You can test that your measurements are correct before cutting the first firring using a couple of short pieces of scrap cut to the required height for the ends of the first joist and check for level between the two and also back to the high spot. If these check out you're ready to go.
Some tips and things to look out for if you're planning to do this yourself.
1. Check each joist to make sure that there are no dips or bumps of any significance alongs its length. Sometimes these can be significant and you may need to contour the firring to match the discrepancies. Don't be tempted to ignore these.
2. Check the condition of each joist to make sure no repairs are needed, this is also a good time to treat the joists against woodworm et al.
3. Make sure that your circular saw can cut to the full width of the new stock timber.
4. After cutting the first firring temporarily fix it in place and test for level along its length and also relative to the high spot. If good, fix it permanently and test for level at various points against this for each subsequent firring.
5. Remember to plan and allow for cable and water services maintenance access.
6. Once all the firings are in place you're ready to fit the new floor.
This is the method I used a couple of years back with our bathroom/dressing-room and will be using it again when I get around to replacing the master bedroom floor and the stairs. I've been putting the latter off as there is a height variation of around 200mm in places and will also be contending with joists dove-tailed into beams. Joy to come - ho hum.
Hope this helps. Oh, by the way if there are no lumps and bumps in the joists you may be able to find a local timber merchant who can cut the firrings for you. If you can check, check and check again your measurements.
Keep us posted,
Steve
A builder would use what are called 'firrings' to adjust the height of each joist to provide a consistent level across the floor. These are strips of suitable construction grade timber about the same width as the original joists and are tapered to form a long wedge shape the length of each joist. The trick is to find the highest spot in the room and from this to measure the height difference at each end of 'each' joist to work out the dimensions of each wedge needed to correct the level. You can test that your measurements are correct before cutting the first firring using a couple of short pieces of scrap cut to the required height for the ends of the first joist and check for level between the two and also back to the high spot. If these check out you're ready to go.
Some tips and things to look out for if you're planning to do this yourself.
1. Check each joist to make sure that there are no dips or bumps of any significance alongs its length. Sometimes these can be significant and you may need to contour the firring to match the discrepancies. Don't be tempted to ignore these.
2. Check the condition of each joist to make sure no repairs are needed, this is also a good time to treat the joists against woodworm et al.
3. Make sure that your circular saw can cut to the full width of the new stock timber.
4. After cutting the first firring temporarily fix it in place and test for level along its length and also relative to the high spot. If good, fix it permanently and test for level at various points against this for each subsequent firring.
5. Remember to plan and allow for cable and water services maintenance access.
6. Once all the firings are in place you're ready to fit the new floor.
This is the method I used a couple of years back with our bathroom/dressing-room and will be using it again when I get around to replacing the master bedroom floor and the stairs. I've been putting the latter off as there is a height variation of around 200mm in places and will also be contending with joists dove-tailed into beams. Joy to come - ho hum.
Hope this helps. Oh, by the way if there are no lumps and bumps in the joists you may be able to find a local timber merchant who can cut the firrings for you. If you can check, check and check again your measurements.
Keep us posted,
Steve
And before you go down the levelling route find your high point - it may just not be possible. In our bathroom the floor drops around 4 inches over the length of the bath and probably another two before you reach the door. If we levelled the floor, it'd mean having a step up into the bathroom and a door height of about 5ft!
I settled for ply over the boards for smooth rather than level and then vinyl for the floor (replacing nasty green carpet). Also went for a panelled bath where I could make the panels and plinths beneath from scratch to accomodate changing height
I settled for ply over the boards for smooth rather than level and then vinyl for the floor (replacing nasty green carpet). Also went for a panelled bath where I could make the panels and plinths beneath from scratch to accomodate changing height
Flyfisher
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Sounds like noj's bathroom floor is like ours. The original floor slopes 5 inches across the 10 foot length so we decided to level it all by fixing new joists on top of the existing floor and then laying a new floor using 18mm waterproofed T&G chipboard sheets, with all the joints glued together. Not terribly 'period' but it feels solid as a rock and will be covered with tiles anyway so won't be visible. But noj is right about the impact on the door height; ours is now just 65 inches, but I'm loathe to make it taller (easy enough as it's only a stud wall) because I'd prefer to keep the original door. The answer of course it to just continue procrastinating. :lol:
fernicarry
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Just done this, in a very similar manner to suggestions by plasticpigeon.
Existing floor boards were quite rotten due to previous leaks and had been hacked around by earlier generations of plumbers, so those all came up apart from directly under the bath. The few decent boards I took out will replace some of those in the hallway mutilated by whover put in the central heating. Joists were treated for worm. Added a sister joist just inboard of the bath to level up directly under it. Its still not completely level but its a good deal better than it was. The bath panel is in one piece and is suspended from the lip of the bath so there is a shadow gap around the bottom of it anyway. 18mm ply over the exposed joists, lots of screws, then 18mm thick UFH boards glued edge to edge and screwed to the ply. All very solid and creak free now. This left the FFL almost exactly the same as it was before so no door modification required.
Its just been tiled so the remaining runs are quite obvious where wall meets floor and around the shower tray but I fully expected that. Absolutely nothing was square, or plumb or parallel. I put a small access panel under the bath and behind the vanity unit in case any investigation is needed in the future. For a tinkerer like me the permanence of tiles is terrifying!
Existing floor boards were quite rotten due to previous leaks and had been hacked around by earlier generations of plumbers, so those all came up apart from directly under the bath. The few decent boards I took out will replace some of those in the hallway mutilated by whover put in the central heating. Joists were treated for worm. Added a sister joist just inboard of the bath to level up directly under it. Its still not completely level but its a good deal better than it was. The bath panel is in one piece and is suspended from the lip of the bath so there is a shadow gap around the bottom of it anyway. 18mm ply over the exposed joists, lots of screws, then 18mm thick UFH boards glued edge to edge and screwed to the ply. All very solid and creak free now. This left the FFL almost exactly the same as it was before so no door modification required.
Its just been tiled so the remaining runs are quite obvious where wall meets floor and around the shower tray but I fully expected that. Absolutely nothing was square, or plumb or parallel. I put a small access panel under the bath and behind the vanity unit in case any investigation is needed in the future. For a tinkerer like me the permanence of tiles is terrifying!
Had a similar problem too. Upstairs floor was wobbly in places so decided to take a look...
Turns out the original floorboards has been badly affected by worm at some point and in places destroyed by a previous electrical and central heating installation. Rather than fix these boards someone has then maid in top a newer set... which didn’t sit right due to broken boards underneath.
I ripped them all out, redid the pipe work in places where it was sitting to high, traeYed the timbers, added in extra supports where needed and laid down new boards.
It may seem more hassle to do but the end result is a study and level floor which will last.
Nothin that worst than doing a job and having to redo it later as you went what seemed like the easy root.
Turns out the original floorboards has been badly affected by worm at some point and in places destroyed by a previous electrical and central heating installation. Rather than fix these boards someone has then maid in top a newer set... which didn’t sit right due to broken boards underneath.
I ripped them all out, redid the pipe work in places where it was sitting to high, traeYed the timbers, added in extra supports where needed and laid down new boards.
It may seem more hassle to do but the end result is a study and level floor which will last.
Nothin that worst than doing a job and having to redo it later as you went what seemed like the easy root.