What should a well-built external wall look like?

[snickarboden]

Make sure to have an air gap behind the exterior panel; without it, there will be problems, i.e., the facade will slowly rot.

/Kent

 

[Mikael_L]

Is the advantage of having the 45 on the outside that there's less risk of drawing in cold through the frame? I imagine, completely without facts, that if you have a 170 on the outside, the cold gets drawn further in through the frame. The risk of moisture getting further into the construction must also be a risk.

Hmm, I don't know how magically much better cross battens make it. I'm somewhat of the belief that the wall's total energy performance isn't affected much by the cross battens themselves, but rather the ratio of wood to insulation affects it most. That is, light studs according to masonite beams give better energy performance due to less wood content in the wall.

But this was my reasoning. 195 + 45 gives a thicker and more insulated wall than 220mm. But above all, I have vertical paneling, so I drive 25x50 nailing battens against the horizontal 45x45, which gives good stability for nail battens and paneling since there's solid wood behind the nailing battens. Otherwise, I think it feels better to go up to 28x70 as nailing battens. The siding doesn't need to be particularly unruly to manage to pull out nails that are only in 25x50 battens of poor wood quality (as the battens often are).

When you run water and electricity in the last 45 space, do you insulate last then? I mean, you run everything and the last thing you do is insulate and then OSB/gypsum.

Yes and yes.

Do you choose to omit wind barrier or external gypsum and do you mean having foam in this outer layer? I looked but couldn't find good examples of this construction.

Foam is wind tight and diffusion open. So if you can just get the joints wind tight (which might be tricky), then it's probably alright to skip other wind protection, i.e., no need for windpaper/wind fabric/external gypsum/asfaboard.

 

[Mikael_L]

Make sure to have an air gap behind the outer panel, without it there will be problems, i.e., the facade will rot slowly.

/Kent

Or slamfärg as I have chosen.
Of course, I still have an air gap, but only 25mm and no extra air slit (masoniteremsa) as johan g suggested.

 

[Mikael_L]

I will build 70+170+70mm cross-laid in my outer walls.

It would have been very nice, especially as 70mm mineral wool boards are infinitely much sturdier and more robust to work with than the flimsy 45s.

But how do you attach the 70mm timber to the vertical studs?
4" nails aren't enough ...

 

[injonil]

You can drill a bit into the stud with a drill that is larger than the head and then screw it in. Or nail it at an angle. I did what suited best at each occasion.

 

[b8q]

I have built 70+170+45 crossed in mine. The 45-layer is the installation layer with a vapor barrier against the 170-layer. The 70 studs are attached to the vertical 170 studs with 160 mm screws. Tip: pre-drill!

 

[Gabbe1]

It would have been really nice, especially since 70mm mineral wool boards are so much sturdier and more robust to work with than the flimsy 45's.

But how do you fasten the 70mm timber to the vertical studs?
4" nails aren't long enough...

Last time I built, I screwed them with 5x110 and it worked perfectly, but this time I've come across a large batch of 6x120 screws.

 

[antnor]

I will be building 70+170+70mm cross-laid in my exterior walls. I would have gone for full coverage insulation on the exterior (not Västkust boards but rather foam) if it wasn't for needing the horizontal studs on the outside to be able to raise the walls easily.

Maybe a dumb question, but I've been wondering how best to attach the foam insulation to the stud frame and how to then attach the battens to the foam. Do you nail the battens directly into the studs through the foam? It feels a bit flimsy considering the lever principle, but is the foam so stable that it doesn't matter? I've tried looking at how foam systems with wood paneling are constructed but don't see those details in their sketches.

 

[Gabbe1]

I want to first clarify that I will not have cellular plastic on the exterior of my upcoming construction, this is not happening due to the need for horizontal battens on the outside in my case.

Otherwise, it works excellently to "squeeze" 70mm S80 grooved cellular plastic between nail battens and studs. I did it in a similar way in a previous construction, then I used 22x95 rough sawn lumber as battens and 6x160mm screws.

 

[Suhagg]

panel
28x70 nail batten
exterior gypsum
horizontal 45 + 45 mm MU
vertical 195 + 195mm MU
ÅB plastic
horizontal 45 + 45 MU + electrical conduit and possibly water pipes.
OSB
gypsum.

If I go like this, is there a need for something that ventilates so that if condensation runs on the exterior gypsum, it can pass the nail batten? Or is it unnecessary? This construction feels tried and cost-effective. Going 70-170-70 felt more complicated and possibly more expensive with all the screwing.

Would
wind barrier-70-170-70
be cheaper and better than having
exterior gypsum-45-195-45
?

 

[Johan Gunverth]

If I build like this, is something needed for ventilation so that if condensation runs on the exterior gypsum, it gets past the battens? Or is it unnecessary?
This construction feels tried and cost-effective. Doing 70-170-70 felt more complicated and perhaps more expensive with all the screwing.

Would
wind barrier-70-170-70
be cheaper and better than having
exterior gypsum-45-195-45
?

As mentioned; masonite strip

 

[Mikael_L]

I skipped the masonite-strip, but on the other hand, I ran the nail battens through the rip saw so I got a 15° sloping top side that directs the water outward at each batten. Then I have slamfärg, which releases moisture quickly and effectively (and lets in moisture effectively during, for example, driving rain :x).

 

[Suhagg]

Of course, Mikael has thought about it, smart, but isn't the masonite strip faster and easier?

Regarding

Would
vindväv-70-170-70
be cheaper and better than having
utegips-45-195-45
do you think?

 

[Mikael_L]

Of course Mikael has thought of it, smart but isn't the masonite strip faster and easier?

Tips I picked up on byggahus.
Both go pretty fast, an hour at the rip saw and you've beveled 1000 meters of nail batten, almost anyway.
At least if you have someone catching behind the saw.

Many houses have none of it, and the facade doesn't fall off anyway.

 

[Suhagg]

Tips I've picked up at byggahus.
Both go pretty quickly, an hour at the rip saw and you've beveled 1000 meters of batten, almost anyway.
At least if you have someone to catch behind the saw.

Many houses have neither, and the facade doesn't fall off anyway.

You're going 15 degrees over the entire batten then?
Feels more sensible and sturdy than constantly fiddling with masonite if you're going to do something.