I have a garage with a pit 5ftx3ft which can't be used as its full of water, i have emptied it via a pump but it fills up again, i have been told that it is a water table, my problem is how do i fill it in. can anyone advise on how to do it.????
Two things you could do with it. A: Fill it with a dry concrete mix, the water will gradually penetrate and it will set. If it is filled with hardcore and concreted over, it might get washed away or settle causing a cavity. B: If you want the pit, get it plastered with waterproof cement (it used to be called "Aquacrete"). Don't try hand mixing, it is an art to be learned (mix the Aquacrete and sand dry, then gradually add water while mixing it). If you add too much water at a time it will float on top of the water.
It should not settle or get washed away provided you compact all the hardcore as you fill it up layer by layer. You need to make sure you have a damp proof membrane and joined to the existing floor's membrane, if there is one. Or paint the whole garage floor with a rubberised floor paint (you need the sort that says it is suitable for garages etc)
