Hanging beams in eaves : bearing onto a wall plate

[ReggieStrant]

Hi, tried asking this in "Building" but to no avail. Wondered if the Joiners here might be more forthcoming. Here goes:

I am wishing to place a narrow walkway in my loft space above insulation for inspection purposes. Although there will be no imposed load above and beyond a brief annual inspection of rafters, it is my understanding that I should never the less treat any laid surfaces as floors.

My intention is to avoid involving the existing joists. Instead I wish any walkways to instead bear only upon load-bearing walls. To this end it is my intention to install additional beams spaced above the existing joists of sufficient strength, so as to support fully the proposed walkway between load bearing walls.

This plan seems pretty straightforward where the load bearing walls are internal. However, because my roof is hipped and these beams must sit above the joists when running at right angles to them (as in the direction of binders), it is impossible to bring the ends of these beams over the external walls and thus support them directly.

I have, in my searches, found a solution to this problem, but only on an Australian site. It is my hope that one of the good folk here might either be able to confirm this as a Building Regs compliant solution, or suggest an alternative. I attach a grabbed pic of the proposed solution as well as a link to the document that contains it.

I'd be very grateful for all and any input.

Cheers.

Page 13, Basic Roof & Ceiling Framing, TAFE : NSWhttp://mikestrade.sydneyinstitute.wikispaces.net/file/view/Basic+Roof+Part+1+pages+1+-+26.pdf

Method of supporting end of hanger

• ReggieStrant
• 12 Sep 2010
• 2

Method of supporting end of hanger

 

[noseall]

That is a very elaborate set-up for an inspection walkway!

Just run some 100mm x 50mm joists at 90 degrees to the existing.

 

[ReggieStrant]

Hear what you say, only my laser level tells me the existing hangers (100x50) are already sagging by ~18cm. They are holding up joists of the same across a 4.6x4.6m room, so I guess there in lies the problem. Rather than "tamper" with the existing and original joisting, I was hoping to "go independent" and thus avoid any suggesting I had altered the ceilings.

 

[noseall]

I think what the image suggests is ok though i would like to see something like a joist hanger as opposed to a single strap doing the work, as a hanger will envelope the timber and run up each side.

How do you intend fixing this, or is the roof open at the mo'?

 

[noseall]

That image does not make sense.

It shows the existing roof joists at 90 degrees to the rafters. This only usually happens at a hip end.

 

[noseall]

However, because my roof is hipped and these beams must sit above the joists when running at right angles to them

DOH!

 

[ReggieStrant]

Ah, we've all done that kind of thing noseall. Most would just edit it out and hope nobody noticed

Anyhow, I'm very grateful for your interest. To wit, I agree whole heartedly with your view in the strap. At the very least I'd like to see straps on both sides. Obviously some kind of sleeve, like most hangers have, would be ideal, as you say, but I've scoured the net for something like that to no avail. I'll probably have to settle for plates. I'm wondering whether standard nail plates would be fine. Peeps seem to use them for truss forming. Or maybe some kind of knee or monent plate.

The roof is on and has been for 40 years! However, I reckon with a mate and careful jiggery-pokery I can get the joist I need up thru the loft hatch and then it will be a simple matter of sliding it into the eaves. It does not have to meet the eaves of the opposite side of the roof as there are supporting walls and the joists change direction past these (the roof is hip & valley / L-shaped), so I can both support it and even use it to counter the rafter thrust of the hip end, should I wish to.

My goal is to resolve all the forces of the walkway vertically down onto the supporting walls and I realise that any flexing may result in a horizontal outward thrusting component. Of course, mitigating all these concerns is the reality that this is an inspection walkway for very occasional use. My chief concern is the weight of the bloody "loft storage panels". You've gotta wonder why they make them so heavy (other than the obvious profit motive!).