Solid or Suspended floor ?

[Paul21]

I have a 1930's house. While replacing the floor ties I found quarry tiles underneath which have been layed on concrete ranging from 25mm to 75mm. Can I replace the floor with a suspended wooden floor or does it have to be another solid floor. I would prefer a suspended floor because of the time scale reqired to lay a solid one. I would be grateful for any advice.

 

[alfiembra]

I wouldn't think you can replace with a suspended floor, the quarry tiles are on a screed so I'm assuming that it is a ground floor which is a concrete slab. Are you meaning a floating floor which is wooden floor boards laid on thin wood straps or foam underlay, in which case yes perfectly feasible.

HTH

Alan

 

[Paul21]

The quarry tiles are on a thin screed this is very powdery so has to come up. I then found that the concrete underneath is also in a bad way and is only 25mm thick in places on top of soil. The floor has to be replaced. I have started to dig out for a new floor but was wondering if I could put in a suspended floor instead as it would be quicker when taking into account drying and curing times for a concrete slab.

 

[alfiembra]

It's really a question of how far you want to go. To create a suspended floor you will have to excavate to depth of at least 18" all over. You then have to seal the excavation with a solum which is usually a damp proof membrane (visqueen 1000 plastic sheeting) and a couple of inches of concrete laid over that. You need at least 6 inches air space below the joists and also air bricks thro' the outside walls to provide ventilation to the solum space. I'm guessing at 8" deep joists, depends on the span but a rule of thumb is measure the span in feet divide that by 2 and add 2 inches. So for example a 12 foot span is 12/2 = 6+2=8 so you would need 8x2 joists at 450 centres. An awfull lot of work and would take a lot longer than pouring a concrete slab. Get a structural engineer or your local building control officer on the job for the best solution.

HTH

Alan