How to proceed with attic storage?

[mike13]

Hey Team, I’m wanting to add attic storage to our house but haven’t had much luck speaking with engineers - who want to take my first born for any advice provided. 

This is the current timber from top plate upwards overlayed to scale on the house plans (see below for house plan dimensions). The large red beam is an LVL that spans the drop zone (3 odd metres).

I’m wanting to know if that LVL will support “floor joists” for mdf floor boards or do I need to create a new subfloor.

I’ve got creative on sketchup and thinking either steel or wood , adding another LVL to assist. The one below is steel, sliding a larger section in adjacent to the LVL to pick up the joist hanger. (If that makes sense).

 

Hoping someone can provide some advice - as I don’t think laying boards straight onto the ceiling joists is wise - which is the advice I’ve been given by attics storage installers! ? 

 This is the same as above but from above.

 This is the house plans.

this is an alternative plan - with timber but only if I’m able to make use of  the LVL.

this is the LVL and ceiling joist hanger to the right.

this is standing on the LVL looking across the area (pre ladder being installed).

 Any help/advice would be appreciated!!

[shelldan08]

It’s about 3 meters, should be fine I would think but I’ll have a look into it, cheers again Mitchell

[MitchellMc]

Span sounds fine for that sized joist, and you're on the right track, @shelldan08! I'd just get the wall and beam assessed by a professional before you start.

Mitchell

[shelldan08]

Yeah I’ll definitely get a professional opinion, just trying to work out if it’s worth doing at all before I did that you know..

my second thought was using the existing bearers, maybe adding a couple extra and put the joists in for the floor on top of them… thoughts?

 

the area is 5.2x3m

[MitchellMc]

To maximise space, it would make sense to install additional bearers @shelldan08. They'd need to be connected to the brick wall and not just set on top of that last ceiling joist. Your flooring could be laid directly on top of the bearers if they were spaced correctly. Or, you could add those additional bearers and place joists over the top. It really will come down to the weight of the stored items. 

Mitchell

[shelldan08]

Thanks a lot Mitchell, makes a lot of sense, storage is just really Christmas decorations and the like, nothing heavy

the last joist is bolted into the wall, does that change anything or would I still need to go from top of the wall

[MitchellMc]

You can connect to the face of the wall @shelldan08. You can't presume that the last joist is sufficiently connected to the wall to support the weight of your new flooring. Its current use is to bear the weight of those two bearers and the weight of the ceiling and joists. Add the weight of additional bearers to it, flooring and storage, and the joist could part ways with the wall. You could either add more Dynabolts to it or bolt an additional timber mounting plate to the brick wall between the existing bearers and use joist hangers to connect your new bearers to it. 

Mitchell

[shelldan08]

Thanks for your advice Mitchell, really appreciate it

[MikeTNZ]

Hi @MitchellMc,

This is where the homework needs to go in BEFORE something like this is even planned.

Having things like RSJ's and building members like that in a structure is all very well, but if there is no tying (as in bolted flanges) of the Rolled Steel joists to substantial timber framing at each end, there is no way that that is structurally sound and will result in eventual catastrophic failure.

Think about this for a moment, all "compartments" of a structure, have lateral and vertical loads put on them, the lateral loads are from the framing that is in compression or tension.

The vertical loads are imposed by the weight of the structural members themselves, like RSJ's, heavy timber beams, etc.

All of these vertical loads need to be supported via the ground floor of the building, to prevent overloading and eventual collapse if there is not enough support.

You cannot simply add more lateral or vertical load to a structure, without addressing what will happen when more load is put on the existing stress loading of a given building.

I'm in no way a structural engineer, but I have seen the results of very poor implementation of building changes, people have been injured badly, some close to death.

Do your homework first.

Cheers,

Mike T.

[MitchellMc]

100% agree, @MikeTNZ. The first step to modifications, such as creating a storage or attic space above a ceiling, would be having a structural engineer assess the space.

Mitchell

[shelldan08]

Hi @MikeTNZ appreciate your input, it’s all early days yet, more interested in what needs to be done so I can work out what sort of money I’ll be putting into it

you said tying down an rsj, I didn’t even know that was a thing! How would that be done? Drilling into the flange and bolting it down into the brick work?

cheers