Fastening of floor joists sizing

[Torbjörn Lindholm]

Hi! I'm going to attach the floor joists of the extension to the existing house. The extension is built rectangularly with the existing house wall as the fourth side. The dimension of the beams is 195x45. I plan to screw an additional 195x45 into the existing house and then attach the joists to it using joist hangers. What dimension and length of screws should be used to attach the beam? And at what distance should the screws be placed?

 

[Torbjörn Lindholm]

Hello! I am going to attach the floor joists of the extension to the existing house. The extension is built rectangularly with the existing house wall as the fourth side. The dimension of the beams is 195x45. I am thinking of screwing an additional 195x45 into the existing house, which I then set the joists into using joist hangers. What dimension and length should be used for the screws that I attach the rule with? And at what distance should the screws be placed?

Expansion screws, is that the only option or are there other good alternatives?

 

[corre]

Is it built with brick, hollow block, or lecablock?
Or do you mean it is cast with concrete vault?

 

[Torbjörn Lindholm]

Is it built with brick, perforated brick, or lecablock?
Or do you mean it's cast with a concrete slab?

So the anchoring to the existing house foundation. It's a brick house with a basement built in '62. So partly anchoring to the cast foundation but also anchoring to the brick higher up when it's time to start the roof.

 

[corre]

You should not attach to the brick as it is usually a cladding and not attached to the house frame in any sensible way. Will the brick wall remain in the extension as an interior wall with that view? Otherwise, it is common to remove the wall, and then the house frame is available for mounting.

On the house foundation, you can use drive nails, they are easy to install and hold well.
Install them at two levels (upper and lower), and offset the holes by 150mm relative to each other.
The depth should be 2/3 into the house foundation, or at least 150mm if it is thicker.

 

[Torbjörn Lindholm]

You should not attach to the brick as it is usually a cladding and not securely attached to the house frame in any meaningful way. Will the brick wall remain in the extension as an interior wall with that view? Otherwise, the wall is usually taken down, which means the house frame on the existing property is available for mounting.

For the house foundation, you can use nail plugs; they are easy to install and hold well.
Install them at two levels (upper and lower), and offset the holes by 150mm relative to each other.
The depth should be 2/3 into the house foundation, or at least 150mm if it is thicker.

Thanks for the answer!
And nail plugs, is that the same as facade plugs, like Fischer facade plug universal at bauhaus?

 

[Torbjörn Lindholm]

Thanks for the reply!
And nail plug, is it the same as facade plug, like Fischer facade plug universal at Bauhaus?

8 mm is probably too small a diameter?

 

[corre]

8mm is plenty if it's as tight as I mentioned.
Another option is thread rod and chemical anchor, I think it's cheaper overall.
Then you can easily have a few less. Maybe a row with cc300 on the thread rod.

How long is the beam, how many joints?

 

[Torbjörn Lindholm]

8mm will be sufficient if it is as close as I mentioned.
Another option is threaded rod and chemical anchor, I think it is cheaper overall.
Then you can have a few less. Maybe a row with cc300 on the threaded rod.

How long is the beam, how many joints?

Thanks for the response! Total length will be around 9.5 m, so at least one joint, but the foundation for the extension includes an old and a new wall, so in the middle these are divided by the original wall, so there will be some relief through it.