Wooden floor in Barn

[JT]

Hi

I have a barn that I am planning to create an office/workshop in. It doesnt need to be in the lap of luxury but I would like it to be relatively warm and dry.

The barn seems fairly well sealled as things are. There are no damp patches even on/after the wettest days.

I have chipped off the internal limey cement, sprayed the wall with a Unibond mix and pointed the stone with cement and unibond.

I am now planning to put a wooden floor in, this will probably just be chipboard on joists.
I know I need to put down a damp proof membrane but was wondering about the best configuration for ventillation and insulation.

The walls are about 1 foot thick but there is one block section that I can fit a vent on to and was hoping to criss cross joists to allow the air to get in at all the wood.

What then is the best way to insulate this?

I was hoping to put fibreglass insulation under the chipboard but will this stop the air flow and increase the likley hood of dry rot in the future?

If the fibreglass is below the level of the vent will i loose any heat retention through the vent.

If anyone has come across this in the past I would be very greatful to hear your experiences.

Thanks

Justin

[ravigarden]

Barn Wood Flooring, Old Rustic Barnwood Floors of Oak and Pine
Old barn wood floors are full of rustic character from nail holes, insect scaring, checking, old knots, cracks and the daily toil of work and weather that was put upon the great North American barn. (such as a threshing floor)

[welsh brickie]

the best way is to compact the floor with a mechanical compactor, lay your insulation down.If its just a workshop 50mm of polystyrene will do.Then lay your DPM on top then lay 100mm concrete thick floor.
If you want to keep a rustic finish, lay and level 25x50mm battens in the wet concrete so you can nail floorboards to them once its set.
With this method no ventilation for the floor is required.

[Perry525]

The point of having floor insulation is to keep the heat in the room and at the same time keep ones feet warm. Having the insulation under the slab means that you have a vast cold slab to absorb the heat from your feet and the barn.
On the other hand if the insulation is on top of the concrete slab, you can have a fully floating t&g OSB floor where your feet will keep warm.
Keeping in mind that barns tend to have high roofs, you will in any event have a problem trying to keep warm, as of course warm air rises.
You may like to consider having a thicker layer of insulation with under floor heating laid in the top of proprietary polystyrene , this will provide a light weight floor with a quick response time and low level heat that will rise round you and keep you warm.