If two of the rafters are cut a Velux window 1340 wide will fit in the loft.
There are 6 rafters in total that reach the ridge, it would be two of these, the roof is hipped and sarked with planks.

It gets 100mph windy here, would this be too big a weakening of the loft?
thanks

misterroy Wrote in message:
If two of the rafters are cut a Velux window 1340 wide will fit in the loft.
There are 6 rafters in total that reach the ridge, it would be two of these, the roof is hipped and sarked with planks.

It gets 100mph windy here, would this be too big a weakening of the loft?
thanks


If it fails put it back how it was?


--
Jim K


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On 27/08/2017 20:12, misterroy wrote:
If two of the rafters are cut a Velux window 1340 wide will fit in the loft.
There are 6 rafters in total that reach the ridge, it would be two of these, the roof is hipped and sarked with planks.

It gets 100mph windy here, would this be too big a weakening of the loft?
thanks

I think the correct procedure is to double up the rafters either side of
the opening to compensate.

--
Mike Clarke

On 27/08/2017 20:12, misterroy wrote:

If two of the rafters are cut a Velux window 1340 wide will fit in the loft.
There are 6 rafters in total that reach the ridge, it would be two of these, the roof is hipped and sarked with planks.

Normally you would put stringers above and below the window - those will
pick up and support the cut rafters. If you want to add extra strength
then nail a pair of additional rafters beside the pair that take the
edge of the window.

So if you start with:

http://wiki.diyfaq.org.uk/index.php/...dowInstall.png

Add extra like this:

http://wiki.diyfaq.org.uk/index.php/...allOpening.png

--
Cheers,

John.

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"misterroy" wrote in message
...
If two of the rafters are cut a Velux window 1340 wide will fit in the
loft.
There are 6 rafters in total that reach the ridge, it would be two of
these, the roof is hipped and sarked with planks.

It gets 100mph windy here, would this be too big a weakening of the loft?
thanks

go on stick in a couple of criple rafters.........

Is this not a question for a surveyor and a structural engineer? You would
not get much sympathy from the planners either if you caved in the roof
without asking for permission, at least not around here.
Brian

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"misterroy" wrote in message
...
If two of the rafters are cut a Velux window 1340 wide will fit in the
loft.
There are 6 rafters in total that reach the ridge, it would be two of
these, the roof is hipped and sarked with planks.

It gets 100mph windy here, would this be too big a weakening of the loft?
thanks

Ha ha.
very funny.

Tiles are havy things. also if its a semi or terraced design anything like
this can bring grief to the neighbours who will look to you for the cost of
repair when their ridge goes up in the air as yours sinks.


Brian

--
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This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"jim" k wrote in message
...
misterroy Wrote in message:
If two of the rafters are cut a Velux window 1340 wide will fit in the
loft.
There are 6 rafters in total that reach the ridge, it would be two of
these, the roof is hipped and sarked with planks.

It gets 100mph windy here, would this be too big a weakening of the loft?
thanks


If it fails put it back how it was?


--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

On 28/08/2017 08:57, Brian Gaff wrote:
Is this not a question for a surveyor and a structural engineer? You would
not get much sympathy from the planners either if you caved in the roof
without asking for permission, at least not around here.
Brian


When I looked at cutting a rafter my tame structural engineer said I
would need a steel frame around the hole to pass the tension on it
around the cut. It was a trussed rafter though, and I could have built a
couple of new ones either side and removed it altogether if I could
pre-stress them to take the same load without the roof moving at all.

If its a typical over engineered Victorian roof you can probably put in
stringers and chop it out but I wouldn't do it without expert advice
first, especially on a hipped roof as I don't know where the stress runs
while I do on a trussed rafter (maybe!).


The hole was to get a solar cylinder into the loft space and it wouldn't
fit through the hatch or where the original cylinder was in the airing
cupboard.

In the end we measured all the spacings and found one with 6mm clearance
so they took the tiles off the roof and carried the cylinder up the
ladders and put it through the hole.

misterroy wrote:
If two of the rafters are cut a Velux window 1340 wide will fit in the loft.
There are 6 rafters in total that reach the ridge, it would be two of these, the roof is hipped and sarked with planks.

It gets 100mph windy here, would this be too big a weakening of the loft?
thanks


Pick a different shape and size of Velux window, I always use Rota.

On Sunday, 27 August 2017 20:12:12 UTC+1, misterroy wrote:
If two of the rafters are cut a Velux window 1340 wide will fit in the loft.
There are 6 rafters in total that reach the ridge, it would be two of these, the roof is hipped and sarked with planks.

It gets 100mph windy here, would this be too big a weakening of the loft?
thanks

Often the adjacent rafters to the opening are doubled up with screws/bolts linking them at intervals.

It's important that the trimmers (above and below the opening are well secured to the doubled rafters.
Usually with metal brackets

On Sunday, August 27, 2017 at 8:12:12 PM UTC+1, misterroy wrote:
If two of the rafters are cut a Velux window 1340 wide will fit in the loft.
There are 6 rafters in total that reach the ridge, it would be two of these, the roof is hipped and sarked with planks.

It gets 100mph windy here, would this be too big a weakening of the loft?
thanks

Leave the rafter in the middle of the Velux.
[g]