Single Storey Extension 7m RSJ

[stash2014]

All,

thinking of building a single storey extension on the back of my house that would include removing the rear wall and fitting a 7m RSJ (to open it up into a more square room) is a 7m RSJ realistic ? cant find much info online of builds what that sort of size beam, or would it be way to hard to prop up ? any info would be appreciated before i start paying structural engineers and architects, Ta.

 

[tomfe]

Done fairly often, you'll need a beefy bit of steel however ~90kg/m I would think.

 

[stash2014]

That is exactly what I'm looking at doing, what is the name of that system your propping up with there? it doesn't look like acrows and strongboys. I can see the joists are resting on the lower beam so are this higher piece in the upstairs rooms ? my downstairs ceiling are reasonably high so is there anyway of doing it without affecting the upstairs rooms ? Ta.

 

[garyo]

Looks slightly more expensive than some acrows too...

 

[tomfe]

You can use acrows and needles/strongboys if space allows. 7m is a fair stretch so I would want something substantial, and calculated, what ever you do. If you want the steel below the ceiling height then you can prop the brick work below and forgo damage to upstairs.
You will also probably need goal posts due to the weight.

 

[stash2014]

don't mind goal posts and am pretty sure I can get below the ceiling height, its propping the place up I'm concerned with, don't really want the needles, would rather just across and strongboys, no idea if that achievable or not, will the structural engineer tell me, the upstairs room is an identical size (no load baring walls) only the outside wall to worry about.

 

[noseall]

don't really want the needles, would rather just across and strongboys

How do you propose threading and lifting a 7m beam into place inside the small gap left by strongies?

will the structural engineer tell me

If he's any good he may give guidance but don't be surprised if it is impractical or unworkable or just WAY over the top.

 

[^woody^]

will the structural engineer tell me

The law (under CDM Regulations) says that he must.

 

[^woody^]

How do you propose threading and lifting a 7m beam into place inside the small gap left by strongies?

I once worked on a job and watched the owner's labourer do this with a pile of blocks at each end and the bottle jack out of his boot.

He must have been on a good day rate.

 

[noseall]

The law (under CDM Regulations) says that he must.

However.....

If he's any good he may give guidance but don't be surprised if it is impractical or unworkable or just WAY over the top.

 

[stash2014]

If the structural engineer specs 2 of the C type steels could the the inner skin be done 1st then the outer one and then bolt them together ? Don't worry I am using a builder for this I just want to understand how it should and could be done before I start talking to them.

 

[stash2014]

How do you propose threading and lifting a 7m beam into place inside the small gap left by strongies?


I have no idea, not entirely sure what the needle ones are to be honest, what I am hoping for is something the props everything up without affecting the upstairs rooms, the ceiling is high enough to have a beam with the upstairs joists onto of it, not entirely sure what the options are regarding propping the place up, the set-up in the above photo looks more serious than i was thinking and if that is the only way it can be done I might have to knock it on the head.

 

[^woody^]

However.....

The SE needs to give more than mere guidance. He is required to provide a safe and detailed method of installing his creation, and this will include getting it to site and into position before the installing too.

He will be responsible for the health and safely of anyone affected by his design, and responsible if he fails to provide such a method.

That's probably as much onerous responsibility as ensuring the thing won't fall down afterwards.

 

[noseall]

The SE needs to give more than mere guidance. He is required to provide a safe and detailed method of installing his creation, and this will include getting it to site and into position before the installing too
.

Crikey, does this mean SE's will be out buying hi-vis, safety boots, some warm clothing and employing a flunky with an umbrella?
I spotted one once, moving carefully amongst some building debris. I have to say his chequered shirt camouflaged in well with his surroundings.

 

[stash2014]

LOL I spotted one the other day, Jeans, chequered shirt, body-warmer ! seems to be the standard attire, clean and pressed !