Boarding loft on hanging beams or only

face-t

Lately I started to seriously running out of space for storage. One small bedroom looks like someone's shed at the moment, I don't like it.
On top of that - during bathroom ceiling change workmen didn't replace wool above it. Although most of it stayed in place anyway - I think all old type insulation, from above ceiling, is sitting now in 3 big black bags. And from what I can see very close to the eaves there is patch with nothing above the ceiling.
So boarding suppose to expand storage and let me help to replace missing insulation.

So I looked into the attic. Insulation is 270mm [done for previous owners on grant], but it sticks so much out, that I considered to :
- buy at least 50x150 timber to screw it over 'hanging beam' to leave small gap for air circulation [for peace of mind I think it should be 50x175mm]
- because hanging beams are 1.75m away, I wanted to join them with other timber battens, and only then
- put on top of them OSB or MDF

Hanging beam is 50x100mm.
Space between joists 450mm

Initially I thought that I'm the only one in the world to do boarding above loft insulation. Then I found you can buy this posts /loftlegs from Wickes or the other company. But when I saw installation video it struck me that they don't do it on "hanging beam", so I have started to search and found this.

Hanging beams

A 'hanging beam' is generally a deep timber beam located perpendicular (at right angles or 90º) to ceiling joists and directly above them. The function of a hanging beam is to reduce the span of the ceiling joists. This allows for a more economic joist size and consistent section. Hanging beams must only support ceiling joists and the attached ceiling materials.

+ https://www.youtube.com/watch?v=qlwq6H2Nj3Q

Legs are generally great but I'm on a budget and they don't look that cheap if you use them in this density as on the Wickes picture [ ]

In papers it says my roof is 35 sq m, insulated with 270mm, the bottom layers is somewhat looking gray and more rough than greenish wool at the top. I'm intending to board no more than 30% for storage and for the eaves access.

I wanted to do it quick to insulate bathroom ceiling and gain access to eaves, but if I would have to do it on the ceiling joists and remove all the insulation.... that would took ages [winter time ages].

Also I have doubt that 175mm legs are sufficient in length and would squash insulation!

As the easy option what can I get to the loft to move safely across beams and insulate?

Thanks

Apodemus

face-t wrote: »

Also I have doubt that 175mm legs are sufficient in length and would squash insulation!

I've not studied these, but always assumed that you screwed them onto your existing joists so that if your hoists are 150mm and you add the 175mm legs, then you can insulate to 300mm, board out and still leave a 25mm air gap below the boards.

face-t

Just measured.
Ceiling joists 8cm high [~3''], hanging beam 10cm high [~4''].

But as top up insulation [I reckon 170mm] is on top of ceiling joists it is above them 170mm [plus lumps of wool sticking further]. Legs are 175mm so the gap is only 5mm even if I squash wool back a little.
I don't think it's good to take a risk of getting no air circulation.

Anyone know can I mount panels on hanging beams?

Apodemus

:eek:

With these timber sizes and re-reading your quoted piece on hanging beams, I think the suggestion is that your ceiling is essentially a non-structural feature, in part hanging from your roof trusses. It may be that none of this is capable of bearing any additional weight (possibly including your own weight if you are up there replacing the insulation!).

stator

I don't know about the structural question but instead of using stilts you should consider what I did.
Use PIR board underneath the floor panels and then there is no need to raise the level. 75mm of PIR board is equivalent to about 20cm of normal insulation (if I remember correctly which I probably don't). Plus PIR board doesn't make you ill by accidentally breathing in tiny fibres.

How old is your house?
Are you sure it's a hanging beam and not connected to the gable end walls like a purlin?

Quorden

Not sure if you're still looking however may want to consider Loftzone products which I've just used to do some of my loft.
Not the cheapest however provide 278mm stilts allowing for that air gap, very easy to install and with the cross beams very sturdy.
The small kit costs about £100 gives you coverage of 2.4m square, or nine standard loft boards in my world, though do need to use the hammer option on your drill when screwing into the metal crossbeams.