Installing a wooden floor is not rocket science - as our Wooden Floor Installation Manual can tell you all about - but the correct preparations can save you a lot of time, money and problems.
One of the main things to prepare before you - or your professional fitter - start installing a wooden floor on a concrete underfloor it is good practice to check the moist content of the concrete.
Moment in time
More often than not this check for moisture gives you either the green or right light to start the actual installation. But never forget, the result only tells you the moist content of the concrete floor at that moment in time! So if you suspect moist problems, or had had problems before, even if the moist check now tells you to "go ahead" with the installation, make sure the cause of your former problem has been solved properly.
And on the other hand, a dry concrete floor now does not always mean it will stay dry for ever. Think of leaks, rising damp etc.
If, in the event there is a moist problem later on and the moist check carried out straight before the installation gave the "all clear" it pays dividend to investigate all possible causes, as we ourselves discovered recently.
A solid Oak mosaic floor was installed a few months ago, concrete floor checked for moisture conditions and readings showed the concrete was below 2% moist content. However, the floor did come up after a while. We suspected a moist problem and investigated. Not just inside the house, but we also had a good look around the house. Often patios are build incorrectly where (rain) water runs towards the house due to the slope of the patio, leaking or damaged gutters can have an effect on the in house situation too. And, as we thought could be the reason here, large plants, trees or shrubs planted or gowning too close to the walls.
When plants are more than beautiful
To cut a long story short, a Drain Doctor confirmed our suspicion the old Wisteria planted very close to the wall outside the effected room had managed to grow its roots right through the drain and was causing a blockage - causing moist to enter the concrete floor from below.
From the Wisteria Website by Francesco Vignoli we have to following information on these very strong roots of this beautiful shrub/plant:
The roots: The wisteria roots spread so strongly and abundantly that if planted near walls or pavements they can easily grow into them causing serious damage . To prevent this from happening it is advised, whilst planting, to insert a corrugated plastic panel which will force the roots to take other directions, as they are unable to pass through it. Place the plastic panel (at least 2m long) 80cm deep, between the plant and the wall or pavement (or the surface to be protected). In the case of walls and pavements made with cement this problem does not exist.
The clients are now waiting for "the Doctor" to repair the drain and then the wait begins for the concrete to dry out completely before the mosaic floor can be reinstalled again.
So, be warned: moist checks only give you a result of that specific moment and be careful when planting large, beautiful shrubs. They can turn around and bite you! (Well, they can bite their way through your drains.)