Jim Coulson on noisy floors
WE have all experienced it at some time or another: A creaky, squeaky floor that always seems to ‘go’ in the same place, every time someone walks over it. Even if you’re lucky enough not to have such a problem in your own house (or your place of work maybe), then you will have almost certainly been somewhere that does have that annoying ‘rasp’ at a certain spot.
So what causes noisy floors, and how can you cure it?
The causes are twofold: Although they are both due to (unwanted) friction, either between the edges of adjacent tongued-and-grooved boards, or between the flooring board and the nails which fasten it to the floor joist.
Chipboard flooring commonly gets the blame, and it’s true that more chipboard floors than ‘traditionally’ boarded floors seem to suffer from this problem. But that’s largely because more chipboard is used than softwood floorboards are, these days. And yet even ‘old’ floors do it: so it’s not simply a fact of modern-day building practices.
The root cause of most floor noises is moisture and movement, not ‘movement’ of the joints (although that is what makes the noise), but a loss of dimension in the joists themselves. And this results from them drying down in situ, after the house has been newly built. This causes a gap between the underside of the board and the top edge of the joist, which then permits ‘play’ when the board or panel is walked on.
Sometimes, this gap may be between the two parts of the T & G joint, where the settlement has caused it to separate, even by just a little.
And it’s surprising just how little lateral movement is needed to generate that annoying noise – where a board or panel is pushing ever-so-slightly down on a nail shank, or the tongue is rotating ever-so-slightly within the confines of the groove profile.
But creak they will unless something can be done. So what exactly to do? Well, that depends on the exact cause.
With ‘settled’ joists causing a gap, the boards then need to be fixed down more positively: so screwing them firmly, or using ring-shank nails, may solve that specific problem. But with T& G joint noise, even using firmer fixings may not fully eliminate it.
So there is almost no alternative but to take up the boards and re-fit them, with a bead of adhesive squeezed along the groove, prior to (re)assembly if that had not been done in the first place. This not only helps to anchor the T & G joint better; it also acts as a ‘cushion’ or ‘lubricant’ in the joint, by preventing the edges from rubbing directly against one another.
(Some people don’t like to glue the chipboard panels together, on the grounds that it could create problems with future maintenance: in which case, something like Vaseline jelly could be used instead, to provide that ‘lubricating cushion’ so long as the main fixing are done properly.)
These days, better alternatives are available to ‘normal’ air-dried softwood joists, which help to eliminate or reduce shrinkage. These are either ‘super dry’ joists (kiln-dried to a low moisture content, to prevent excessive shrinkage and thus gapping); or I-joists made from engineered timber and OSB composite sections, which are claimed not to ‘move’ at all (one brand even advertises itself as ‘Silent Floor’: thus reckoning to eliminate joint and nail noise altogether).
When all is said and done, that old nemesis, moisture content, is at the back of all that annoying creaking!
Jim Coulson FIWSc FFB is director of TFT Wodexperts, based in Ripon, North Yorkshire