*Treatment stage* Fen Cabin Studio - Build Diary. UK

[Soundman2020]

Looks like that might work, but check with your electrician. Personally, I prefer the rigid PVC type, that I then heat with a blowtorch (gently!), with a bending spring inside, then I can shape it any way I want, and it will keep that shape once it cools. It's a bit tricky to work with, but it gets the results you want, every time. You have to be careful to only heat it just enough that it becomes soft and bendable, not so much that it discolors (or burns! ), and finding large diameter bending springs isn't easy either... You want one that's a little smaller than the interior diameter of the conduit, so you can slide it in and remove it afterwards easily, and it needs to be long enough to go around the largest curve you need to do... or you can do the curve in two parts. Attach a piece of strong wire to the spring, so you can pull it out after the PVC has cooled. Anyway, that's the way I like to do it, but your electrician might have his own preference, and your materials may be different from what I use here....

- Stuart -

[Waka]

Had the electrician come to visit today for the quote, which he expects to get to me early next week (after he gets his info back from the A/C installers).

The plan is to run 40A from the house to the studio.
As the cable will be attached to the house external wall and then goes underground between the house and studio, I've been told to use SWA (Steel wire armored) cable as this won't require trunking on the walls or underground and doesn't need conduit in the wall cavity of the studio.
He will install all sockets surface mounted.
Cabling for the lights will be between the ceiling insulation and ceiling in the inside out ceiling.
Sockets and lighting will be on separate radial circuits.
He informed me that I'm not allowed to run the network cables in the same entry point as the 230V electrical, due to a damaged cable possibly passing the high voltage through the adjacent data cable.

So annoyingly I'll have to have a second entry point for the data cable.

Dan

[Soundman2020]

and then goes underground between the house and studio, I've been told to use SWA (Steel wire armored) cable as this won't require trunking on the walls or underground and doesn't need conduit in the wall cavity of the studio.

Exactly. Good call. If you are going underground without metal conduit, then armored cable is, indeed, the way to go.

He will install all sockets surface mounted.

And light fittings? And switches? And distribution panel? All must be surface mounted. No penetrations....

Cabling for the lights will be between the ceiling insulation and ceiling in the inside out ceiling.

Sockets and lighting will be on separate radial circuits.

He informed me that I'm not allowed to run the network cables in the same entry point as the 230V electrical, due to a damaged cable possibly passing the high voltage through the adjacent data cable.

Right. Keep all your signal cables (low voltage) in one conduit, separate from your electrical. Signal might also include things like CCTV, alarms, cable TV, intercom to the house, doorbell, and other similar stuff. That can all go in one conduit.

So annoyingly I'll have to have a second entry point for the data cable.

Unfortunate, but it ain't the end of the world, if you do it right.


- Stuart -

[Waka]

Yep all light switches etc will be within the trunking surface mounted.

I've started attaching my polythene vapour membrane now.

Ceiling is done. It was a nightmare trying to fold the polythene around the noggins etc.

I couldn't put the membrane on top of the joists as I wouldn't be able to get the insulation in!

So I've attached the membrane tight up against the insulation at the top of each joist and wrapped it underneath the joists.

ceiling polythene.jpg

Onto the walls today.

Dan

[Soundman2020]

I've started attaching my polythene vapour membrane now.

Whoaa!!!! Wrong location for vapor barrier!!!!

It goes UP AGAINST THE LEAF ITSELF, not in the middle of a cavity, nor over insulation. It must go directly ON the leaf surface. If there is a cavity, that potentially creates the right conditions for condensation to form on the barrier itself.... Potential mold / fungus source.

- Stuart -

[Waka]

The inner leaf is going to be attached underneath the vapour barrier, this is the location approved by building control. Directly above the vapour barrier is insulation, directly below will be two layers of plasterboard (inside out ceiling modules).

Dan

[Waka]

I've finished attaching the wall membrane today. Just need to tape the joints and inspect for holes.

wall membrane.jpg

Dan

[Soundman2020]

The inner leaf is going to be attached underneath the vapour barrier, this is the location approved by building control. Directly above the vapour barrier is insulation, directly below will be two layers of plasterboard (inside out ceiling modules).

It's still in the wrong place: It is supposed to be directly ON the leaf material (drywall OSB, ply, whatever), with no insulation or air gaps. I'm very, very, VERY surprised that passed inspection. That's a mold hazard.


- Stuart -

[Waka]

The inner leaf is going to be attached underneath the vapour barrier, this is the location approved by building control. Directly above the vapour barrier is insulation, directly below will be two layers of plasterboard (inside out ceiling modules).

It's still in the wrong place: It is supposed to be directly ON the leaf material (drywall OSB, ply, whatever), with no insulation or air gaps. I'm very, very, VERY surprised that passed inspection. That's a mold hazard.


- Stuart -

As far as I'm aware it's standard installation practice in the UK.

Attach the vapour barrier to the studs, then place the plasterboard over the top and screw into the studs.

For the ceiling, my modules will be up tight against the membrane and the insulation will be weighing it down against the boards. What airgap are you referring to?

What installation method are you proposing, Stuart?

Dan

[Soundman2020]

Attach the vapour barrier to the studs, then place the plasterboard over the top and screw into the studs.

Exactly: But that's not what you are doing!

ceiling polythene.jpg

Unless you plan to make attach drywall that goes up the sides of your joists, screwed into them, then across the top, pressed up tight against the plastic, then back down the next joist, then under the edge of that joist, then etc..... Is that what you plan to do?

For the walls, you show that it is laid over the outer-leaf joists: there will then be an air gap, then comes your inner-leaf drywall....

I assume that what we see in your photos is all outer-leaf, correct? Or are we already looking at inner leaf? It can't be the inner-leaf, I'm pretty sure...

- Stuart -

[Waka]

Hi Stuart,

Yep this is all inner leaf (you must have missed the pictures of it being framed).

The plasterboard about to be installed is the inner surface of the room.

Dan

[Soundman2020]

So the inner-leaf is NOT being built inside out? Which is what you said a while back?

So if the walls are not being built inside-out, then the walls are OK, but no matter which way you build the ceiling now (inside-out or conventional), it is not OK. If you are going with an inside-out ceiling, then the plastic should all be on top of the joists, not wrapped around the underside. Your ceiling modules would then press up against it, and you would be able to seal the modules to the joists, correctly. With the plastic there, you can't do that. And if you are going with a conventional ceiling (not inside-out) then there is going to be an air gap above the drywall. So either way, it is not correct.

- Stuart -

[Waka]

The ceiling is the only inside out surface in my design. The walls are conventional.

Hmm... I hadn't considered that sealing the ceiling modules would be affected by wrapping the vapour barrier around the timber. I wonder whether this could be addressed without having to change the membrane. The reason I wrapped it under in the first place was because it was almost impossible to get the membrane over the joists without messing up the insulation.

I'm going to look into a way to seal the inner ceiling modules even with the membrane there.

My fall back option could be to "box in" the joists by lining them all with a layer of plasterboard, which is then sealed against the ceiling modules.

Dan

[Waka]

After taping my vapour membrane joints, I started with the OSB on the walls. One of the short walls and two corners are fixed in place.

OSB started.jpg

OSB corner.jpg

gap left for caulk.jpg

[Waka]

I got some help today and managed to fit the rest of the OSB sheets on the walls. I've done 75% of the space between the joists. So after I've finished that, I've got to put some little squares of OSB beneath each joist and caulk it all.

Next jobs :
The ceiling modules > caulk > box in the joists (as the vapour barrier is around the joists) > screed the floor to smooth it off > wall plasterboard.

Dan

OSB between joists.jpg