Frame directly on the support beam or on the floorboard?

[andewid]

I am going to build a 15 sqm storage shed and I wonder if I can place the frame directly on the floor joists/beam or if I should put the floorboard first and then place everything on it?

There seem to be different suggestions?

Placing directly on the beam:

• Simpler and allows for the possibility to insert or replace the floor later
• The floor may flex a little on the short side where there is no floor joist. CC=60.

Placing on the floorboard:

• More stable floor.
• Greater risk of moisture in the floor that cannot be replaced then.

What do you think? I have already built the frame with beam/floor joists. It is on post holders on pillars, meaning no moisture comes up from the pillar. Then I thought I'd have some gravel and a plastic mat on the ground to prevent more moisture.

EDIT: I saw the Wood Guide's suggestion to place the frame directly on the sill: http://www.traguiden.se/TGtemplates/popup2spalt.aspx?id=4689&contextPage=5946

 

[JanneL]

I would have placed it directly on the beam. However, add another joist after the short side so you have support for the floor just before the wall.

 

[andewid]

Thanks for the quick response! Yes, I was thinking about that. I can add that afterwards.. I'm in a bit of a hurry to get the frame and roof up, you see.

 

[para]

I laid the floorboard first because it was the fastest. However, I had to be extra careful to cover the construction when it rained, as the particle board is a bit more sensitive to rain than just a frame structure.

If you place the frame directly on the beam, you should probably cross-support between the floor joists so the particle board is supported underneath on all sides.