Do I Really Need A New Sub Floor For My Wooden Floor?
Preparation, preparation, preparation. Unless you get the sub floor preparation right, the chances of your wood floor installation being a total success are slim; in fact it could even turn into a disaster. There is nothing worse than spending thousands of pounds on a beautiful new hardwood floor, only to find that it feels like a trampoline when you walk on it!
So, if sub floor preparation is so important, why do some companies pay so little attention to it in the UK? The answer is usually money. A new sub floor can cost nearly as much as your new wooden floor, so you might be forgiven for thinking ‘If I can’t see it, what’s the point in having it?’
The point is that your sub floor is the foundation for your floor; just like a house, a floor must have a solid foundation. British Standards state that a sub-floor must be smooth and level to within +/-3mm over a 3 metre span before a new wooden floor is fitted. So basically, if you place a large straight piece of wood over your existing sub-floor and you see gaps bigger than 3mm, then you should really be going for a new sub floor.
However, this does depend on the type of installation:
If you are having a ‘secret nailed’ installation, and your sub floor is uneven, the act of nailing the new floor to the sub-floor will at least make it feel solid underfoot. Although it still won’t be completely level, this won’t be a critical problem.
If you are having a ‘floating’ installation and your sub-floor is uneven, then you will feel it moving when you walk over it; it may even feel a little bouncy.
If you are having a ‘glue down’ installation, then the sub floor has to be absolutely level, otherwise you will use twice as much glue and will probably need to do twice as much sanding as well.
Generally, wooden sub floors are far more forgiving than concrete ones – because of course you can nail a new floor down on top of them. If you have a concrete sub floor then it will usually need some self levelling work if you want to achieve an even finish.
As always, it is vital to work with an experienced and reputable installer who can give you advice based on your exact requirements.