Hi All,

I was wondering if you could help me.... We have had a brick shed
built with a flat roof. The rafters (8"x2") sit on a wall plate and
are approx 4.6m long. The roof is made of ply (3/4" I believe) and
has 2 rows of 8x2 noggings between the rafters.

I was looking to store a load of things between the rafters (e.g. the
mountain of spare timber from the house renovation!) but the noggings
are now in the way.

Given this is a shed roof with no plasterboard etc. I was wondering
what purpose the noggings was and whether I can remove some/ all of
them?

All help appreciated.

thanks

Lee.

On Mar 14, 1:36*pm, Lee Nowell wrote:

Given this is a shed roof with no plasterboard etc. I was wondering
what purpose the noggings was and whether I can remove some/ all of
them?

Noggings have two purposes, once the roof is up (they also help as
formwork when building). One is to stop the joists moving from side to
side, the other is to stop them tipping over diagonally. Both of these
would usually be triggered by a sideways shear force on the roof
(often from wind load) relative to the walls, and at right angles to
the joists.

You need this. You still need this, you need to keep this. However you
might not need as much of it as you currently have.

If the roof is plywood and well-screwed to the joists, then there's no
scope for sideways movement, once the roof is decked out - although at
least temporary nogging would have been needed during construction.
However there's still scope for a toppling of them.

Do you have noggings at the ends of the joists too? Those will also
help. They're not unusual if the joists are on a wallplate, although
they'd be rare if the joists are on metal hangers.

It's unusual to see so much timber nogging these days. Most of it is
now done with diagonal steel strips, either pre-formed, or off the
roll. The pre-formed are neat, but force a particular joist spacing.
These diagonal strips are also considerably stronger against a
toppling collapse than free-floating timber nogging - although 8" deep
is pretty strong either way (if nogged full-depth, with good
attachments). Shallow timber can wrench itself off the nails holding
the nogging. A timber nogging added afterwards is pretty much useless
for this anyway, as it's hard to attach the components well enough.

The following is almost certainly a breach of building regs and the
Geneva Convention. However....

If you have the plywood deck attached well enough, it will brace the
joists against sideways shifts. If you nogg joists from at least one
side, so as to make boxes, you are still supporting each joist against
topple - even better if three joists and two noggings are joined. If
there are good end noggings too,even better.

So in this case, I would personally consider (and remember I've not
seen the building) removing _some_ of the noggings to make extra space
for long storage. However I wouldn't de-nog both sides of a joist. I
wouldn't even de-nog two adjacent joists. If I needed storage for 2.5m
lengths, I'd also only remove one of the noggings from a gap, not
both. I would only remove what I needed, but I would be happy to
remove some of them.

On Mar 14, 3:37*pm, Andy Dingley wrote:
On Mar 14, 1:36*pm, Lee Nowell wrote:

Given this is a shed roof with no plasterboard etc. I was wondering
what purpose the noggings was and whether I can remove some/ all of
them?

Noggings have two purposes, once the roof is up (they also help as
formwork when building). One is to stop the joists moving from side to
side, the other is to stop them tipping over diagonally. Both of these
would usually be triggered by a sideways shear force on the roof
(often from wind load) relative to the walls, and at right angles to
the joists.

You need this. You still need this, you need to keep this. However you
might not need as much of it as you currently have.

If the roof is plywood and well-screwed to the joists, then there's no
scope for sideways movement, once the roof is decked out - although at
least temporary nogging would have been needed during construction.
However there's still scope for a toppling of them.

Do you have noggings at the ends of the joists too? Those will also
help. They're not unusual if the joists are on a wallplate, although
they'd be rare if the joists are on metal hangers.

It's unusual to see so much timber nogging these days. Most of it is
now done with diagonal steel strips, either pre-formed, or off the
roll. The pre-formed are neat, but force a particular joist spacing.
These diagonal strips are also considerably stronger against a
toppling collapse than free-floating timber nogging - although 8" deep
is pretty strong either way (if nogged full-depth, with good
attachments). Shallow timber can wrench itself off the nails holding
the nogging. A timber nogging added afterwards is pretty much useless
for this anyway, as it's hard to attach the components well enough.

The following is almost certainly a breach of building regs and the
Geneva Convention. However....

If you have the plywood deck attached well enough, it will brace the
joists against sideways shifts. If you nogg joists from at least one
side, so as to make boxes, you are still supporting each joist against
topple - even better if three joists and two noggings are joined. If
there are good end noggings too,even better.

So in this case, I would personally consider (and remember I've not
seen the building) removing _some_ of the noggings to make extra space
for long storage. However I wouldn't de-nog both sides of a joist. I
wouldn't even de-nog two adjacent joists. If I needed storage for 2.5m
lengths, I'd also only remove one of the noggings from a gap, not
both. I would *only remove what I needed, but I would be happy to
remove some of them.

Thanks very much for your help Andy.

In reply to your questions
- the ply is well screwed down now
- the noggings are not at either end but in 2 rows down the middle. I
guess roughly splitting the roof into 3 sections (if you see what I
mean)?

Could I more aggressive with removing them if I replace them with end
ones?

thanks again

Lee.

On Mar 15, 12:59*pm, Lee Nowell wrote:

Could I more aggressive with removing them if I replace them with end
ones?

I'm a bit out of my depth here, so I would now be looking at the
standard textbooks etc. to see what the rules & recommendations were
on sizes and spacing. It's one thing to bend these, but ignoring them
completely isn't a good idea.

I'd be hesitant to rely on end noggings alone, as the span would then
be quite large. I'd probably try to remove one instead, if that would
give me long enough storage for my timber. Otherwise it's a good
idea.

It's also quite awkward to attach noggings to joists, once they're in
situ - easier to add them as you go along. So think this out first and
come up with some decent attachment. After all, they're only as good
as their attachment.