Shed Base

[ricky101]

Hi,

Been watching someone build a shed/home office type structure, but think they are doing it wrong, but do not want to say anything to upset them if we are wrong, so would like to know whos right ?

They have constructed the base as below onto compacted mot , but the floor bearers have beed placed all around the perimeter as well as length and sideway pieces, so creating a fully enclosed mesh of separate areas. The top half of that area has been filled with kingspan .

The shiplac walls of the shed come down as far as the top of the concrete base, No idea what they are going to do to the exposed concrete base edge.

To us there should be ventilation under the floor otherwise the mositure around the concrete will just condense in that space rotting the timer and ply floor over time ?

 

[JohnD]

If I understand your pic correctly

The dpm will prevent water passing from the ground into the slab
(Depending where ground level is)

But the slab is exposed round the edges of the shed walls

So rain will fall on it and it will become damp.

This is quite a common mistake with shed builds.

If the wooden bearers are not raised, for example on a dwarf wall with DPC to isolate the wood from the brick, then the bearers will rot

And the cavity needs to be ventilated on at least two sides to permit airflow.

 

[ricky101]

Yes, thanks, that was our thoughts, but needed confirmation, do we tell him or not is our next question ?!

 

[JohnD]

You can try to do him a favour, he might not welcome it.

 

[ricky101]

Know what you mean, why risk getting your head bitten off, sad but true.