Shed floor-what do i use!

[kingtrowel]

I am making a metal motorbike shed, and i want to put a wood floor in.
It will be inside and sat on metal joists, so it will not be directly exposed to the elements,however it may get a bit damp and cold.
Would external plywood be ok to use or do i need marine ply?
Or do i need something totally different? Unfortunately money is a factor, but i want it to last.
Any help appreciated

 

[big-all]

heeelllooo kingtrowel and welcome

18mm exterior ply with joists around16"appart assuming the motorbike is a decent weight
if its a heavy weight around 12" centres to stop bouncing

if you can keep the motorbike to one area [one side] you could go for 24" centres and an extra joist or 2 under the bike area

you could also chamfer the edge of a bit off 6mm ply to give you a "hard stand " on the area off the floor the bike stands and replace it when it gets dammaged through oil /water /the stand ect

 

[JohnD]

metal sheds are notorious for condensation, even if ventilated.

If you can line it, fully, that will prevent condensation.


as it is under cover I presume it is a security measure?


You wil also want a big ringbolt or something into the ground slab for your chain.

I like All's idea about the hard section, but I would have thought steel plate under the stand. If it is a big bike with a centrestand, there will be a LOT of weight concentrated here.

 

[kingtrowel]

Thanks i think i'll go for 18mm exterior ply. The weight will be pretty evenly spread as it will be supported on the paddock stand bobbins at the back, and on the front wheel,it's only a smallish sportsbike anyway (R6).

As for the condensation issue, it will have a 30mm box section frame clad externally with 1.2mm galv sheet.
Would it be enough to clad it internally with 6mm ply as i have plenty of that? I could put insulation between but would i be better leaving a cavity?

BTW sorry JohnD when i said the floor would be inside i just meant it will be under the cover of the shed roof and not exposed to the elements.The shed will be outside in the garden.

 

[JohnD]

6mm ply sounds good. I presume the cavity will be about 30mm off the frame? you could use 25mm polystyrene slab, or maybe fibreglass matt. Put an extra layer in the ceiling. You want a vapour barrier to prevent moist air from inside reaching the cladding.

people usually say ventilate the cavity, the steel will get wet anyway on both sides from condensation but if galvanised and painted, and you alow any water to run out from the bottom, not a major problem. You won't be running baths or boiling kettles in there, or breathing a lot.

Allow enough ventilation for the bike to dry off when you put it away wet or your tools will go rusty.

If you decide to provide electric light, you can use a 300W or so tube heater, which generates enough warmth (in a ventilated and insulated small shed) to keep it dry.