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Steel beam height

I am looking to have a steel beam installed in my extension to open it all up.

I was considering trying to have the steel pushed up to give us a flat ceiling when coming from the existing room to the new extension. Is this a hard task to undertake when trying to notch in the floor joist from the upstairs into the steel beams? Would the upstairs flooring need to be ripped up to allow access to do this or can it all be done from the ground floor(kitchen)

I am now weighing up these options to know ahead of time what it would be like to do or would a normal steel beam installation be the better way forward?

I am also struggling with steel beam calcs due to having a block and beam floor and the existing footings being 1600mm in the ground as its all suspended floors. I am trying to stay away from a box frame so wonder if a large beam across an opening of 5m would suffice?

2 Answers from MyBuilder Extension Builders

Best Answer

Hi Fordie

Although it’s more involved installing the steel beam within the first floor structure it is very effective from an aesthetic standpoint when all finishes are applied and the area is complete.

All works can be carried out from below, take down enough ceiling each side of the beams location to give you enough working space. Temporarily prop the first floor from below either side of the beam and then you can cut back the joists to provide room to install the beam.

To re-instate the floor structure afterwards I would advise fitting a timber in the webs both sides of the beam, bolting these through so they are connected together. Using joist hangers fitted to these timbers, extend your existing joists by running a length of timber down the side of each joist, fixing them together to provide strength. When all the joists have been extended and sit in the new hangers you can remove the props and start putting it all back together again.

With the above solution, you would need a structural engineers calculations and details to ensure structural integrity is maintained and building control sign off the works.

Hope this helps!


Answered 29th Mar 2019


we get this issue all the time and have devised an engineering solution that will allow the beam to be flush without disturbing the ceiling too much and keeping cost down.

With the 5m you can possibly avoid the box frame if the loadings are not too great and we can get the piers or columns to give us sufficient lateral restraint.

Happy to advise further.


Answered 31st Mar 2019

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