Shed Build WIP
- Thread starter The Bear
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markyl
New member
Hi guys,
Sorry if I've put this in the wrong place, first post
Been looking at this with interest as planning something almost identical and note the comment about it's an example of a model example of how to build a shed. Want to do something to last as this method keeps the water away from the base and not just treated bearers sitting on a concrete pad, which would get wet.
Question - why does the ply or osb need to be on the inside? Conscious of moisture etc.
Was planning on (from inside out) stud work 3x2, then 9mm ply, then breathable membrane, then vertical batons, then outside horizontal cladding/ sarking. The batons allowing air gap behind the featheredge.
If it's not to be insulated as it'll be just 'a well built shed', then does this sound ok?
Would value your expert thoughts!! Cheers guys.
Sorry if I've put this in the wrong place, first post
Been looking at this with interest as planning something almost identical and note the comment about it's an example of a model example of how to build a shed. Want to do something to last as this method keeps the water away from the base and not just treated bearers sitting on a concrete pad, which would get wet.Question - why does the ply or osb need to be on the inside? Conscious of moisture etc.
Was planning on (from inside out) stud work 3x2, then 9mm ply, then breathable membrane, then vertical batons, then outside horizontal cladding/ sarking. The batons allowing air gap behind the featheredge.
If it's not to be insulated as it'll be just 'a well built shed', then does this sound ok?
Would value your expert thoughts!! Cheers guys.
RobinBHM
Established Member
Your construction detail will work well.
I made a large shed with 100x 50 studs, 18mm osb3, tyvek housewrap, 50 x 25 tiling battens, feathedge.
Before fitting the tyvek membrane, I stapled on one strip of 200dpc around the bottom edge of the perimeter and positioned about 50mm below the bottom edge. It acts as a drip and protects the bottom plate from any rain.
The ply or osb can be fitted inside or outside. I chose the outside as it gives support to the breathable membrane and leaves space between the studs internally for insulation, although it will then need an internal sheet to finish the walls.
I think it is possible to fit the celetex on the outside of the studwork then tape the joints, screw on 50 x 25 tiling batten and then cladding. The foil on the celetex once taped is a waterproof barrier so no need for membrane. I would look at tyvek site and kingspan for recommended construction detail.
Either way, having a small cavity will have a massive impact on the weathertightness and life span of the claddjng and framework.
You could use either 11mm or18mm osb3, its quite waterproof and cheaper than ply.
Tyvek housewrap is very good but cromar vent 3 also works and is cheaper. My shed is bone dry inside, no hint of condensation, even though ive yet to complete the outside claddjng, so the osb and tyvek definitely work.
I made a large shed with 100x 50 studs, 18mm osb3, tyvek housewrap, 50 x 25 tiling battens, feathedge.
Before fitting the tyvek membrane, I stapled on one strip of 200dpc around the bottom edge of the perimeter and positioned about 50mm below the bottom edge. It acts as a drip and protects the bottom plate from any rain.
The ply or osb can be fitted inside or outside. I chose the outside as it gives support to the breathable membrane and leaves space between the studs internally for insulation, although it will then need an internal sheet to finish the walls.
I think it is possible to fit the celetex on the outside of the studwork then tape the joints, screw on 50 x 25 tiling batten and then cladding. The foil on the celetex once taped is a waterproof barrier so no need for membrane. I would look at tyvek site and kingspan for recommended construction detail.
Either way, having a small cavity will have a massive impact on the weathertightness and life span of the claddjng and framework.
You could use either 11mm or18mm osb3, its quite waterproof and cheaper than ply.
Tyvek housewrap is very good but cromar vent 3 also works and is cheaper. My shed is bone dry inside, no hint of condensation, even though ive yet to complete the outside claddjng, so the osb and tyvek definitely work.
blackrodd
Established Member
RobinBHM":j766s13a said:
I fully agree with Robins reply, the only criticism I would have on this very good build, is that I would put some joist support down the centre of the floor joists, to strengthen it, unless of course you were to up the joist size to 6x2,
But I would still fix bridging down through.
You never quite know what heavy bargain can come along, at a later date!
Regards Rodders
Markyl, Welcome to the forum
My take on this is slightly different to above.
If you are having insulation there is a best way round, and that is to have the ply (or OSB) inside. The ply being full of glue effectively acts as a vapour barrier. If you put the ply outside you risk trapping any moisture that gets into your cavity and insulation, inside with no way out of the building. If you do put the ply on the outside you may as well get rid of the breather membrane, since there will be no vapour coming through the ply for it to let out.
If you are not having insulation it matters less which side it goes on. If on the outside you'll presumably have open studwork inside so nowhere for moisture/vapour to get trapped.
As I said just my take and others will disagree and have had no problems with their construction. You have already identified the biggest thing you can do is get any wood at the base off the damp ground above a DPC. Then any shed well built with decent stud sizing, nice thick ply giving it solidity and well fitted outside sheathing will lost a long time compared to anything you will buy for a similar price regardless of whether the ply is inside or out.
I have moved since I built this shed, when I moved it had been up 5 years. It was showing no signs of degrading at all and wasn't even ready for a new coat of paint. I wish I could have brought it to the new house with me.
Good luck with your build and remember we like WIPs like this one of mine
Mark
My take on this is slightly different to above.
If you are having insulation there is a best way round, and that is to have the ply (or OSB) inside. The ply being full of glue effectively acts as a vapour barrier. If you put the ply outside you risk trapping any moisture that gets into your cavity and insulation, inside with no way out of the building. If you do put the ply on the outside you may as well get rid of the breather membrane, since there will be no vapour coming through the ply for it to let out.
If you are not having insulation it matters less which side it goes on. If on the outside you'll presumably have open studwork inside so nowhere for moisture/vapour to get trapped.
As I said just my take and others will disagree and have had no problems with their construction. You have already identified the biggest thing you can do is get any wood at the base off the damp ground above a DPC. Then any shed well built with decent stud sizing, nice thick ply giving it solidity and well fitted outside sheathing will lost a long time compared to anything you will buy for a similar price regardless of whether the ply is inside or out.
I have moved since I built this shed, when I moved it had been up 5 years. It was showing no signs of degrading at all and wasn't even ready for a new coat of paint. I wish I could have brought it to the new house with me.
Good luck with your build and remember we like WIPs like this one of mine
Mark
tomf
Established Member
Just to add to this osb is not really a vapour control layer, osb is good as a wind barrier but has a medium vapour permeability so you should NOT relay on it and should add a layer of plastic on the warm side of the wall.
