Damp garage floor - solutions?

[Flying machine]

My garage floor is concrete and seems to get condensation on the surface. It's detached from the house. Is there anything that can be done as I think that this can't help the car sat on it with condensation on its under-surface. Would those fancy checkered tiles do the trick?

[CraigyMc]

Why's it damp? Is there moisture rising off the floor, or is the floor cold enough for condensation to be forming on it from moist (presumably warmer) air above?

C

[DrDeAtH]

You need a flow of air over the surface to wick away the condensation. Fitting a plastic floor over will make the concrete sweat. Once dry, the surface can be sealed.

[digger the goat]

Do not put any floor covering on the floor until you have worked out why this occuring...
As above... beading water on the surface is more likely to be condensation...
Venting the garage is a good start..
If this is not working ( which it will..in most cases), consider a breathable membrane for the roof and also insulating the walls( again with ventilation and membrane).
Failing this, the floor will need taking up and a suitable insulation and DPM installing before relaying...
Otherwise..... Try a low emittance heater ( my first choice !!) Available online for about £15-00.
Whatever you do... Ventilate...

[Ozzie Osmond]

digger the goat said:

Whatever you do... Ventilate...

This.

Because if it doesn't work you'll be into quite serious building work arising from no damp-proof membrane under the floor. Chances are you may have single brick thickness walls and no damp course too.

[digger the goat]

^^^^^^^^^^^^^^^^

[V8RX7]

My friend has a garage that suffers with a soaking wet floor at certain times - he can get a couple of mm of water across it.

We were sure the conc floor itself was at fault but someone suggested duct taping a steel plate to the floor (when dry) then looking under it when the floor was damp.

Sure enough the floor under the plate was bone dry - hence it was condensation

[digger the goat]

Normaly a lack of DPM (damp prof membrane...ie plastic sheeting between concrete and sub-base)
OR DPC ( damp proof course....ie non permeable membrane in brick course.including slate in older builds.. usually 2 courses abouve ground level minimum) Will result in damp in the floor and wall to a height of around 1 metre above floor level..
Anything 'standing' on the floor or above the 1 metre level will nearly alsways be condensation due to a lack of ventilation/ambient heat. Combination of both are possible, therefore exagerating the problem..

No I haven't copied this from anywhere... This is My opinion as a builder of many years..
Please feel free to correct me..!!