Boarding my loft with an awkward design

ecraig

Hi all
I am hoping for some friendly guidance. 
I have provided below a picture of my loft,  and wonder if anyone has ideas on how I can create a walkway of loft boarding to the end of it?

As you can see my loft is designed like \|/ and it seems difficult to get loft stilts in place because there is no space directly in the middle.
I thought about adding some 4*2 from \---------|---------/ as below and then laying the loft boards on top:

Does this seem like a good idea?

I'm quite capable of using a saw,  tools,  drill and spirit level,  loft legs,  but I'm stumped at how I use this big area in the middle most effectively and safely. 

Any thoughts welcome. 

EssexExile

In the absence of a response from anyone who knows what they're talking about, I would say that it isn't a good idea. Every piece of timber in that sort of roof is designed to take a small load in a particular direction, there are lots of fairly small timbers so all those small loads add up to enough to support a heavy roof. If you start putting vertical loads on those diagonal members they will distort and take the roof down with them.

Section62

ecraig said:

...and wonder if anyone has ideas on how I can create a walkway of loft boarding to the end of it?

Are you looking at creating a storage area, or just a way to access the far end with less risk of putting your foor through the ceiling?

If the former, then I would endorse EssexExile's comments.  You would need expert advice on how to make use of any spare loadbearing capacity in the roof structure, without causing unwanted deflection of either the roof or ceiliing.

If the latter, then what would the access requirement be for?

ecraig

Thanks for your kind comments. I'm looking to make a walkway so that some solar pv equipment can be housed in the loft. That equipment will be at the very end attached to some timber.
I simply want a safe passage so nobody puts their foot through the ceiling. 
I think one option Is to use loftlegs like this:
T```````T\  |  /T````````T

Then I could span another board from the end of one loft leg to the other but it does mean attaching some 4x2 to the 'King post'. No bearing on the diagonals.. 

Would be a bit like this:

          ____|____
T```````T\  |  /T````````T

The roof can support the panels, by the way. But the builder doesn't give guidance on how to board the loft as they don't design it for storage of stuff...

Any further thoughts please? 

Section62

ecraig said:

Any further thoughts please? 

If it is only for access by one normal-sized person at a time then I would pick one side and fix a length of 3x2 between the king post and the diagonal on that side, approximately as per your purple lines, and set to the same height as the ties in the background of that picture. (assuming this is going to give adequate headroom)

Then use 4x2's - laid perpendicular to the trusses - which are supported by the 3x2's and in turn support the side-edges of chipboard laid on top of the 4x2.

The 4x2 effectively acts as a bridge, spanning multiple trusses so the load is distributed over several at a time.

You need to think how the 3x2 is attached to the trusses so it is secure without reducing the strength of the truss, that there is sufficient headroom, and about the safety of the person using the 'catwalk' in terms of the risk of them stepping/falling off the side in that elevated location.

I would limit it to one diagonal to the king post (not diagonal to diagonal as per your purple lines) as it limits the amount of normal differential movement which the additional timber restricts to minimum - in other words the amount one diagonal may need to move relative to the king post is less than the amount of potential movement needed between the two diagonals.

That's the approach I'd take, but my previous advice stands - that you should really seek expert advice.

ecraig

This is excellent advice. Thanks so much. Will need to think some things through