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Right in my daughters room we have a Mezzanine floor and I want to extend it.
I need to bridge the gap between the edge of the existing mezzanine and the opposite wall with new joists.
The mezzanine edge is a wooden joist and the opposite wall is brick. (Structural old outside of house)
Whats the accepted best practice for this?
get a structural engineer type person to do some calculations and talk to building control to see if it's notifiable.
how big is the gap?
[edit] it may be if it is notifiable that they want the existing structure to meet current regs before you can add to it, though.
Gap is 1480mm
Want to avoid regs and engineers 😉
You should use the TRADA tables (joist deflection limits) to calculate whether you can come off the leading joist of the mezzanine and span to the facing wall without any other vertical support (pillar) or a more substantial member like steel beam.
Attaching to the facing wall can be done simply enough with a wall plate and some appropriate anchor bolts at specified centres.
My approach to such things would usually entail speaking to builder mates in the pub and doing tons of research online and reference to the trada tables and if it looked like it all didnt seem to be really easy and well within an 8x2 @ 400mm joist limits get an engineer in. But that's me, on my house, not advice.
EDIT: Whats the span of the leading joist of the mezzanine? ANd what are the joist dimensions?
Current mezzanine meets regs but is also why it was finished 'as is'
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[url= http://www.flickr.com/photos/fantasticmrmatt/10946790133/ ]photo[/url] by [url= http://www.flickr.com/people/fantasticmrmatt/ ]fantasticmrmatt[/url], on Flickr
so was it not finished off so that it didnt make a complete floor?
how do you access the mezzanine at the moment?
how much of the gap are you going to bridge, some, all?
1480mm bridge
x 900mm wide
What size in the existing mezzanine joist and what is its span?
Was my initial thought, along with joist hangers off it and the opposing wall plate Stoner suggested. If, from the TRADA tables, the existing joist isn't big enough, you could either double it up by bolting another to it and setting each end into the wall, or use steel fitch plates bolted either side of the beam.
Lots of ways to accomplish what you are wanting to achieve, do however look to the building regs for peace of mind.
Sort of, it had to be 50% of the base room floor space, this meant that access is via a pull down loft ladder. My eldest is 7 so that's out.
So I need to bridge that gap as a mini landing and put in a staircase with hand rail up to it.
Mezzanine joist span is 3m
Im sure that would be eminently doable.
SO you want to run a landing continuing down the wall to the end wall, bridging across to that end wall from the leading edge of the mezz.
I can have a look at the tables later but dont expect it to be anywhere near the limits. But need to get on with cooking for now.
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[url= http://www.flickr.com/photos/fantasticmrmatt/10947234896/ ]025[/url] by [url= http://www.flickr.com/people/fantasticmrmatt/ ]fantasticmrmatt[/url], on Flickr
This is taken from the ground floor, the first floor is the upsatirs and you can see the mezz joist above.
So it's double but runs entire width so 5m not 3m and has a stud wall underneath half way (ish)
p
So what do we reckon?
Rawlbolt a beam to the brick and uses hangers?
or
Put a hole in the wall and cement the beams in?
Personally I'd let the joists into the wall. Never like the idea of fixing a timber to the wall to then bear structurally from. Are the originals 8x2's?
Best bet to go into the wall tbf and wrap with a membrane. Seen too many plant decks fail and fall when joiners use rawl bolts into a wall then span off that timber.
All the weight is on the bolts and you never know how good the fixing is inside.
Wall it is 😀
