Dilatation between existing building and new extension?

[mats12]

Hi, Im pretty unexperienced engineer as far as reconstructions go so for some of you this question may seem stupid...

Im dealing with an extension of existing building. Extension is masonry structure with wooden roof.
Floor dimensions are cca 5 m x 3 m. Im wondering if I should make dilatation between new and existing building. Im kinda concern that without dilatation there will be some cracking between new and existing masonry wall because of soil deflections under new walls.

What do you guys usually do in situations like this?

As far as roof above extension goes... it has to be connected to existing building, but I think that timber is flexible so thats not a problem?

 

[thaidavid40]

I definitely recommend that you have an isolation joint between the new and existing construction here. Check out this link for a typical detail for intersecting walls construction:

http://imiweb.org/02-010-1311-control-joint/

Good luck,
Dave

Thaidavid

 

[mats12]

thanks for answer. will look it up.

how about if we have existing stone walls and we anchor new walls into stone?

 

[Once20036]

If you're putting a joint between the new/old walls, are you also putting a joint between the new/old roof? That doesn't look like it would be too stable.
Otherwise, are you tying the roof together but leaving the walls separate? So when the addition sways under a wind load you're transferring load at the roof but not the base?

I don't have much experience with wood, but my first thought is to tie them together from top to bottom, and fix any cracks that may occur in the existing masonry.

 

[thaidavid40]

@Once20036 - The isolation joint detail referred to the OP does include ties to connect the new construction to the existing.
Dave

Thaidavid