Anchoring or not in existing wall during extension.

[Martin_B]

This is what I mean, as according to principle c.



Source:
Dimensionering av träkonstruktioner
Part 1
EDITION 2:2016

 

[bossespecial]

You probably have walls on the 3 sides, then they are stabilizing. If you only plan to have glass without any wall stumps, that's another matter. Then it is extremely important that the roof (stabilized with shear action or bracing) of the extension is anchored to the existing house. Regarding your initial questions, you might want to contact the designer about your thoughts on integrating new and old without an expansion joint. He surely has a handle on all the conditions that may not be evident in this thread.

 

[Martin_B]

Regarding your initial questions, you might want to contact the constructor about your concerns regarding building new and old together without a movement joint. He surely has a grasp of all the conditions that might not all be apparent in this thread.

No, I just borrowed the thread, it's not me building ..but I still find the topic interesting.

 

[bossespecial]

Ahh, sometimes it goes a bit fast

 

[bossespecial]

The stability of a building is the most important thing, it doesn't matter how strong all the beams are if the house blows over anyway. The stability of a building is the first thing to figure out as this is extremely complicated to solve at a much later stage (This of course rarely applies to regular houses as these are usually low and full of walls).

 

[hagv]

Yes, it's strange how you get such different advice. Almost everywhere you read, it sounds almost hysterical that you can't build attached. "It must be standalone!" blah blah.
I was looking for information about this a while ago, and principle solutions for different constructions, how you should connect to an existing building, how the connection at the roof should look so it doesn't leak, but I couldn't find anything concrete that solves the issue of it being standalone, yet stable and still sealed against the existing building without letting water in during rain, etc.

So you built the extension with 3 walls, so to speak? And thereby utilize the existing building's outer wall as an inner wall in the extension?
How do you get stability in the extension when the wind blows from the side then?
It should collapse like a house of cards if it isn't anchored to the main building and there's no 4th wall built with sheet material?

I have poured the foundation as a square and built with Leca, so the foundation has 4 sides.
I plan to frame even on the side facing the existing building, partly because the existing wall isn't straight and I have support for the middle floor. However, it will be something like 45x70 or 45x95 on that wall instead of 45x170 + 45x70 as it is on the other 3 walls. Then it will be OSB and plasterboard on all walls.