Rendering over OSB??

[mpooley]

I'm building an outbuilding to be used as a workshop.
It will be timber framed and lined with OSB
I was thinking of facing the exterior with 18mm OSB3. covered with building paper of some sort the top half of the wall would then be shiplapped and the bottom half covered with expanded metal and rendered.
Will the OSB3 be suitable for under the render?

Thanks

Mike

 

[Deluks]

Yep.
Plywood can also be used instead of OSB, some prefer it including me. Slightly more expensive probably.

 

[mpooley]

Thanks Mate!

 

[mpooley]

actually can i do without the building paper under the render and the shiplap?
i've just found out how much it costs!!!!

Mike

 

[JohnD]

Shiplap is not entirely weatherproof. I have sarking felt behind mine, under the battens.

You might consider using polystyrene slabs, which would give you insulation as well.

 

[Deluks]

I got a part used roll of tyvek from eBay for my shed walls.

 

[mpooley]

I am going to insulate so maybe polyurethene is the way to go?

and i'll check up on tyvek prices

thanks
mike

 

[Deluks]

Do you mean polythene? If you use breathable on the outside then you will need vapour barrier on the inside usually*. Polythene on the warm side of the insulation does the job. John's right though, polystyrene slabs would be much cheaper and still do the job. Don't forget to put ventilation in the room, lots of people build sheds and workshops airtight and wonder where the waters coming in once condensation builds up.

*If you're a mechanic and usually work with the garage doors open then you won't need to worry to much about this stuff.

 

[JohnD]

A lot of moisture comes up through the floor if there's no dpm.

 

[mpooley]

Dont worry i will be insulating and putting in a vapour barrier.
And I meant Polystyrene when i said polyurethane (Grey moment)

so are you saying if i use polystyrene in the walls between studs i WONT need any external breather paper?

Mike