RSJ - Length Issue / Can you get in sections ?

[bobbym]

Looking to get a single storey rear extension built (10m x 4m) - it is the width of the house.

I want to knock down the existing rear external wall so that the completed extension is completely open plan.

Thing is do i need a 10m long RSJ to support the structure or can you get an RSJ in sections (say 4 x 2.5m) to make up the length and bolt / weld together ?

Access to the rear of my property is tight and with the weight / length of a 10m RSJ think I would struggle to get this in place.

Appreciate any thoughts / comments.

Thanks.

 

[kevindgas]

you would need to speak to building control at your local authority as some would consider it others won't

 

[Static]

10m taking roof and first floor would be something like 5-600mm deep beam..
Can you break it into sections, sure but only really should be putting 1 joint in the whole length.. so break into 6m & 4m

Hire a crane to get the beam over your house.. would only cost a few thousand with all the oversail agreements and stuff..

You may also need some general stability additions to the property when removing a complete wall..

Lucky you just won the lottery or this would be all rather expensive..

 

[RonnyRaygun]

You can splice RSJs, but to span 10m you are going to need something huge!

Have you had calculations done? You will probably need either a portal frame or a box frame to give lateral stability to the building if you are removing 10m of masonry. How much masonry will be remaining to the sides of the opening and what will be above?

If you have had calcs done your engineer should specify what steel will be used and what connections you will need.

 

[bobbym]

Thanks for the responses - looks like it can be done but is going to be a pretty costly job.

 

[geraint]

would love to know what size section of steel over 10 metres....

probably as deep as your house....

and as a splice....

 

[freddiemercurystwin]

As already mentioned 5-600mm. Rule of thumb is depth = 1/20th span. Unless the OP has a floor-ceiling of 2.8m or more it'll be impractical anyway without columns. IMO a huge downstand would look worse than say two 200X200 columns and a smaller downstand. Seems madness to have such a deep beam in a dwelling.

 

[RonnyRaygun]

I've got a feeling you'd still need at least a 457 section as a beam and columns almost as deep, just to get the connections to work.
Never done a domestic design with such a long span...might stick it into a computer program tomorrow out of interest!

Maybe the OP should think about having a "feature" CHS somewhere in the middle Then could probably have 203 UCs and a join above the CHS...much easier to handle and a lot cheaper!