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What should a well-built external wall look like?
It sounds like a common tried-and-tested variant. It might go in that direction, but perhaps it’s just as well to use a 50mm insulation board on the outermost layer.Niklas9 said:panel-boarding 12mm (clamps the fabric and provides an air gap) - diffusion-open wind barrier - 45x45 beams horizontally with insulation - 45x145 beams with insulation (or 170, 195mm if more insulation is desired) - plastic - 45x45 beams with insulation, electrical, plumbing - drywall (or plywood, OSB, and drywall)
What I'm going to build is a single-story traditional rectangular house.daugaard said:
What does Insulation layer 45 mm MU mean?
Is it a pure layer with just insulation and no frame, and how is it connected
120 mm vertical studs + 120 mm MU
with
"inner wall" vertical 95 mm + 95 mm MU
in that case?
The question: "What does Insulation layer 45 mm MU mean?"
In general, it could mean both 45x45 studs + insulation as well as just insulation, everyone writes a bit differently.
But in the specific text you have there, it must mean only insulation, when you see it in its context.
They are probably not meant to be connected at all. Both walls are sufficiently robust and stable to stand on their own and become straight and nice.
One could imagine placing a small piece of 45x45 stud in one or two places in the wall to keep the 45 mm gap quite constant everywhere.
But the intention is to get a layer of completely uninterrupted insulation.

In general, it could mean both 45x45 studs + insulation as well as just insulation, everyone writes a bit differently.
But in the specific text you have there, it must mean only insulation, when you see it in its context.
They are probably not meant to be connected at all. Both walls are sufficiently robust and stable to stand on their own and become straight and nice.
One could imagine placing a small piece of 45x45 stud in one or two places in the wall to keep the 45 mm gap quite constant everywhere.
But the intention is to get a layer of completely uninterrupted insulation.
An exciting wall, i.e., double shell wall with uninterrupted insulation in between. But personally, I would like the uninterrupted insulation layer to be thicker, so it would really carry the job properly, say at least 95 mm MU.Suhagg said:What I am going to build is a single-story traditional rectangular house.
What does Insulation layer 45 mm MU mean?
Is it a pure layer with only insulation and no frame, and how is it connected
120 mm standing studs + 120 mm MU
with
"inner wall" standing 95 mm + 95 mm MU
in that case?
Found these two.

Another one, perhaps not so easy and cheap to replicate yourself for a stick-built house.
Ifs placing some nail battens and using foam insulation might not be so hard.

Here you see our unique implementation. The secret in the wall construction lies in our patented wall stud. This makes it possible to insulate a whole 34 cm at almost the same cost as a normally insulated house. The U-value of our wall is 0.125. The stud consists of an inner load-bearing stud and an outer nail batten. Between these, foam insulation is placed and finally bound together with nail plates.

Our patented wall stud
The advantages are many:
Few thermal bridges
Material efficient and affordable
Low weight
Large wall thickness implies modest cost increases compared to other types of stud constructions.
Wall in Passive House Granbäck
1 Wood panel.
2 PAROC XMV 080, Windproof.
3 Crossed frame with 45 mm insulation,
PAROC UNS 37z, Wall/Floor Joist Board Wood.
4 Bearing structure with 170 mm intermediate insulation, PAROC UNS 37z, Wall/Floor Joist Board Wood.
5 Freestanding insulation layer 170 mm (without studs) PAROC UNS 37z, Wall/Floor Joist Board Wood.
6 PAROC XMW 001, Plastic Foil.
7 Installation layer with 70 mm insulation,
PAROC UNS 37z, Wall/Floor Joist Board Wood.
8 Plasterboard.
U-value: 0.09 W/m2

Another one, perhaps not so easy and cheap to replicate yourself for a stick-built house.
Ifs placing some nail battens and using foam insulation might not be so hard.

Here you see our unique implementation. The secret in the wall construction lies in our patented wall stud. This makes it possible to insulate a whole 34 cm at almost the same cost as a normally insulated house. The U-value of our wall is 0.125. The stud consists of an inner load-bearing stud and an outer nail batten. Between these, foam insulation is placed and finally bound together with nail plates.

Our patented wall stud
The advantages are many:
Few thermal bridges
Material efficient and affordable
Low weight
Large wall thickness implies modest cost increases compared to other types of stud constructions.
However, those nail plates conduct quite a lot of heat. :S
But sometimes I've been tempted to copy that concept but use masonite strips instead. Some glue on them and then shoot 4 long staples with a staple gun.
It's about the same result as those double walls with full insulation in the middle, but you can work with the studs a bit more as if it were construction with solid wood studs.
But sometimes I've been tempted to copy that concept but use masonite strips instead. Some glue on them and then shoot 4 long staples with a staple gun.
It's about the same result as those double walls with full insulation in the middle, but you can work with the studs a bit more as if it were construction with solid wood studs.
Suhagg said:
Yes indeed, solid wall.Wall in Passive House Granbäck
1 Wood panel.
2 PAROC XMV 080, Windproof.
3 Cross-laid stud frame with 45 mm insulation,
PAROC UNS 37z, Wall/Floor Slab Wood.
4 Load-bearing frame with intermediate insulation 170 mm, PAROC UNS 37z, Wall/Floor Slab Wood.
5 Freestanding insulation layer 170 mm (without studs)
PAROC UNS 37z, Wall/Floor Slab Wood.
6 PAROC XMW 001, Plastic foil.
7 Installation layer with 70 mm insulation,
PAROC UNS 37z, Wall/Floor Slab Wood.
8 Gypsum board.
U-value: 0.09 W/m2
455mm insulation, total wall thickness is about the depth of a closet. :O
But somewhere it has to stop as well. Cost-wise, the time it takes to build, the space it consumes. There’s barely anything left of the slab when you make 40-45cm thick walls 
A golden middle way then.
A moderate budget and a constructionally simple version. 380mm insulation.
Panel 22mm
28-70 Nail battens (also provides stability)
50 mm facade board
Wind barrier
120 mm vertical studs + 120 mm MU
Insulation layer 95 mm MU (no stud)
"inner wall" vertical 70 mm + 70 mm MU
Plastic
45mm horizontal + 45 MU (installation layer)
OSB
Plasterboard
A golden middle way then.
A moderate budget and a constructionally simple version. 380mm insulation.
Panel 22mm
28-70 Nail battens (also provides stability)
50 mm facade board
Wind barrier
120 mm vertical studs + 120 mm MU
Insulation layer 95 mm MU (no stud)
"inner wall" vertical 70 mm + 70 mm MU
Plastic
45mm horizontal + 45 MU (installation layer)
OSB
Plasterboard
It sounds like a wall with really good insulation value. But I'm wondering if you've written wind barrier inside the facade board? Is a wind barrier needed when you have a facade board, and if so, shouldn't it be on the outside?
That might be correct. Either you can probably make tight joints on the facade board. But I'm wondering about the wind barrier; it feels like it should be closest to the insulation, i.e., against the frame, but I don't know.daugaard said:
Something I'm thinking about is if wall construction can go overboard.
Sure, I hope to have this house for the rest of my life, but how much should a wall really cost and when does it become excessive?
There are a lot of different pictures like these, and they all look different, but you get some kind of impression. (see below)
I need to get some perspective on what things cost
Let's say I have a 145 sqm single-story house and build just to meet the building codes today.
We say
Panel-Nail batten-Exterior gypsum-195-45-plastic-45-OSB-Gypsum and that frame costs 200,000 SEK in materials to build.
If I make a high-end wall
Panel-Nail batten-50mm facade board-Wind barrier-120-95 (insulation layer)-70-plastic-45-OSB-gypsum
does it cost 250,000 SEK in materials or more?
Do you "earn" back this money by having about 100mm more insulation and a more complex construction?


Sure, I hope to have this house for the rest of my life, but how much should a wall really cost and when does it become excessive?
There are a lot of different pictures like these, and they all look different, but you get some kind of impression. (see below)
I need to get some perspective on what things cost
Let's say I have a 145 sqm single-story house and build just to meet the building codes today.
We say
Panel-Nail batten-Exterior gypsum-195-45-plastic-45-OSB-Gypsum and that frame costs 200,000 SEK in materials to build.
If I make a high-end wall
Panel-Nail batten-50mm facade board-Wind barrier-120-95 (insulation layer)-70-plastic-45-OSB-gypsum
does it cost 250,000 SEK in materials or more?
Do you "earn" back this money by having about 100mm more insulation and a more complex construction?


I seem to recall that in one of these, there is a discussion on calculating the optimum, but the parameters involved are electricity price, insulation price, expected trend on electricity price, interest rate, so it can get a bit complicated/there's a large uncertainty in the calculations...
Edit/addition:
I mean the optimum in insulation thickness versus cost, at some point you start insulating more than you gain from it, or you could insulate more without losing in the long run.
Edit/addition:
I mean the optimum in insulation thickness versus cost, at some point you start insulating more than you gain from it, or you could insulate more without losing in the long run.
It is possible to calculate it. As JOW writes, you have to take chances on some future prices, but also on potential future maintenance and the like.
You also don't need to compare with other parts of the house to determine if the action is worth it or not. If you lower that wall in the picture from 20% to 10%, you have saved that energy regardless of what else you have done. But you should not calculate in %, as everything is interconnected in an unmanageable way. Calculate what two different wall options consume in kWh, and then compare these two in the light of construction cost vs future operating cost. Don't forget the discount rate on the construction cost.
Then your choice will affect the percentage of all the components (iso, vent, etc.), but it is really quite insignificant.
I calculated this way on the windows when I was considering choosing much more expensive super-insulated types. But there was no way the calculation gave me any reason to choose 0.8 in u-value. So we chose standard triple-glazed, they were probably 1.1 or 1.2. But many times there is a factor that is not purely economic either. There is a nagging worry in me that we may feel drafts from the inferior windows. :|
The same might apply to the walls, perhaps you hate very deep reveals and would rather pay for a little extra heating. Or vice versa.
You also don't need to compare with other parts of the house to determine if the action is worth it or not. If you lower that wall in the picture from 20% to 10%, you have saved that energy regardless of what else you have done. But you should not calculate in %, as everything is interconnected in an unmanageable way. Calculate what two different wall options consume in kWh, and then compare these two in the light of construction cost vs future operating cost. Don't forget the discount rate on the construction cost.
Then your choice will affect the percentage of all the components (iso, vent, etc.), but it is really quite insignificant.
I calculated this way on the windows when I was considering choosing much more expensive super-insulated types. But there was no way the calculation gave me any reason to choose 0.8 in u-value. So we chose standard triple-glazed, they were probably 1.1 or 1.2. But many times there is a factor that is not purely economic either. There is a nagging worry in me that we may feel drafts from the inferior windows. :|
The same might apply to the walls, perhaps you hate very deep reveals and would rather pay for a little extra heating. Or vice versa.