In which layer should I install the window?

[slipperman]

Hello everyone,

I am in the process of replacing windows on a facade. When I have replaced windows previously, I haven't really considered which facade layer the outer side of the window should be in, but I have, of course, set the window flush with the facade and then added the trim. Done!

Now that I read the window manufacturer's recommendations, they clearly state that the window should be placed in the warm layer, and I interpret that as the window frame surface should be flush with the windproof layer (I hope you understand). This method of installation means that the window must be offset with the ventilation depth under the board (12 mm) + board thickness (22 mm) before you can add the trim.

This seems incredibly complicated. Is this the window manufacturers' way of disclaiming any warranties? Is this how windows have to be installed nowadays? If so, are there any practical solutions for offsetting or is it the long road that applies? Should one disregard the recommendations? Have I got it completely wrong??

Hoping for some advice from you forum members!

Take care,

//Per

 

[vojma]

I have been explained that the window (the frame) should be aligned with the outer edge of the insulation. This means that casing must be done, usually both on the inside and outside.

 

[titanium]

Here you have the window installer's absolute best guide:
http://www.elitfonster.se/Archive/O...ad av fönster i vägg. 5.10.2005.WEBBkvali.pdf

A window should simply not be positioned too far out or in the facade for optimal function. Placement far out has its advantages, and far in has its own, as you can read in the pdf from Elitfönster.
Normally, windows are set just as "vojma" says, in line with the outer insulation or windproof layer.
I don't think you should complicate it as you say. Place the window where it is easiest to install and seal. If it differs by a centimeter, it doesn't matter.
The most important thing is that you insulate properly around the window according to best practices. Some construction companies are a bit sloppy with this.
Elitfönster once again has the answer on how to insulate

 

[slipperman]

Quote Elitfönster: "Place the window in the wall's warm part According to TMF's recommendations, recessed placement is best for the reasons given below: In exterior walls built of different layers, there is always a risk of water and condensation occurring. Additionally, the outer part of the wall construction moves differently in relation to the inner warm part of the wall. The reasons why the window should preferably be placed in the wall's warm part, i.e., deeply recessed, are many: Water that penetrates the wall construction's air gap is prevented from penetrating towards the room side of the wall and therefore does not burden the window. Fastening to the wall structure becomes safer and better. Proper sealing is easier to perform. Placing the window in the warm part of the wall gives the window's interior a higher surface temperature, which counteracts cold drafts, cold radiation, and surface condensation. An outer niche reduces air movement around the window's exterior and thereby improves its thermal insulation. A sheltered position extends the durability of the surface treatment.

If the window is not placed in the wall's warm part, special attention must be paid to the wall’s detail design so that proper ventilation and water repulsion in connection to the window can occur."

It is possible, but you have to be meticulous. Thank you for the answer, In Electissimus Fenestre Veritas!

 

[apotekarnes]

In old houses, windows are often flush with the paneling, but back then they also used wood of much higher quality than in today's windows. A window that is positioned at the outermost part in this way is exposed to rain and inclement weather much more, and if you have a deep window recess indoors, you also get drafts and condensation/ice on the panes more easily, which wears them out. I think deeply recessed windows are unattractive and therefore usually set them approximately flush with the wind paper, resulting in a casing of 40mm (nailing rule + panel).

Casing is not a huge job if the wall is straight. Just remember to make notches at the bottom so that you can slide the under flashing in a few mm to avoid gaps between the ends of the flashing and the casing.