Have you had a look to see if there is anything obvious going on under the house with the piers?
So we got tired of the old chessboard style tiled floor in our L shaped livingroom - kitchen and ripped them all out with a shovel and barrow. There wan 15-20mm mortar sitting on a sheet of plastic over the yellow tongue subfloor so it all came up quite easily.
Now of course we have solid bamboo floating floorboards ready to lay but walking around the room on the yellow tongue there is noticeable slope in some places. The worst areas appear to be near the external house walls and the hallway along 2 sides of the bathroom which is on a raised slab. Slab is higher than joists so they appear to have ramped the yellow tongue to make up the difference. The rest of the house is on brick piers with bearers and joists.
I suspect the builder knew the floor was not level from the beginning and laid that mortar base over it to cover it. I doubt it is due to the piers sinking over last 25 years. If it was surely the edges of floor at the walls would be lower than the centre of the floor. Thankfully the main livingroom floor area seems to be the flattest part buy still has more than 10mm variation.
So i need some advice on what my options are now. I'm dealing with about 55 square metres here so if we are talking self levelling compound it's going to cost a fortune.
What's the easiest, best, longest lasting way to get a flattish floor ? doesn't need to be perfect 1mm flatness.
Also is there a part of the building code on max 'step' heights on floors at doorways ? Like the chrome strips most houses have at the bathroom ?
Cheers!
Have you had a look to see if there is anything obvious going on under the house with the piers?
As far as floor surface transitions go, 5mm is the limit if you are looking at meeting fully accessible design guidelines - Livable Housing Australia
Otherwise it seems to be anything from 10-15mm.
If it has been a bodgy 'slope the floor up to meet the next area' type of thing, and if you're really keen on levelling it, you might have to use a combination of putting down new sheets of yellow tongue (available in 19, 22 and 25mm thickness) and masonite underlay and levelling compound....but even that sounds like a horrible fudge.
The horrible 'do it properly' approach might be to cut the floor out along the walls, add shims (or plane down existing glued on structafloor after punching the nails down) to the top of the joists and relay the flooring. A sheet of yellow tongue (3600x900) is $40, so that's about $12 per square meter.
DIY electrical house wiring details suitable for Australia - http://goo.gl/9d33T (PDF file)
Over the years I've learnt one thing, most times it's easier and usually cheaper and always quicker to do it properly..
This way you can completely plan what you're attempting rather than make it up as you go...and end up with an ordinary job..
FWIW a pull up and replace seems like the go to me, but it's not my money...
Once up you can "sister" the joists that are low with new ones set to the right height. If the existing are in good enough shape, 90 x 35mm treated pine batten screwed to them
Pick the timber carefully to get the straightest you can.
Thought there might be easier advice but tend to agree about redoing the the floor properly. Don't know to what extent, depends on what is bad. It sounds like that the house has sunk a bit in the early part and finally stabilised. I also expect that the bamboo flooring will need a flat floor to be properly laid.
Have you thought about getting a restumper to have a look and try and lift and level the floor then pack the existing piers
So i called in a big favour from an old mate Builder and Engineer who came and had a look at the issues. In the end he decided parts of the house have settled or sunk a bit some years ago and it would be too risky to try and jack it back up so long after for a few reasons, 1 being the place is built on oversize bearers and they will be too stiff to flex back up. The other reason being the original builder appears to have been a bit rough on his levels so it's very hard to tell where and what was level to start with.
So the house stays where it is and we work around it, just like the original builder did with his cement mortar levelling method.
The problem with the 'rip out the floor and level the joists is, other than it costing a fortune, it would create a big step at either the back door or the internal doorways. The trouble with any other method is that they will also create the same problem. I never measured the flatness of the old tiles but now i will i had.
Does anyone know where to find some good info on how to lay battens? A lot of people talk about them but i can hardly find any info on them