Simon wrote:
On 12 Aug, 20:34, "BigWallop" wrote:
"Simon" wrote in message

...
On 12 Aug, 08:37, Simon wrote: On 12 Aug,
04:20, John Rumm wrote:

BigWallop wrote:

snipped

Well, the struct eng that validated my roof design says they would
want 150+vat for a site visit to confirm some drawings I do for them
and to check end bearings etc, then about 105+vat for calcs to
confirm
and also design an acceptable way to hang a purlin from an existing
RSJ. Does that seem reasonable ?
Question is - do I bother ?
Only thing as regards purlin on RSJ, is its loading on one side that
could try to twist the RSJ. I'm sure I'd get away with just doing it,
but for insurance purposes, etc it may be a good idea.
Simon.

It will be money well spent for the peace of mind you get with a
proper job.
I'd say "go with the struct' eng" and make sure the whole thing
lasts the
years you want it to.

I do the same as you. I look at it for months, then decide I can do
the
work without problems, then change my mind and ask someone I know,
with a
greater experience of the actual calculations, to come in and tell
me I am
correct. But it seems to have been a good way of doing things, just
for the
peace of mind I get knowing the work is done properly.

I've had a look at the RSJ over the other side of the house (the
kitchen), and that is interestingly two parallel RSJs 3.5" by 7" with
similar flange and web sizes to the other 5" x 6" RSJ. I'm guessing
the parallel ones start with stretchers rather than headers.
It would be interesting to have seen these houses being built. Massive
gobs of lime mortar and beefy RSJs being thrown around everywhere
would be quite a sight !
Simon.


It may also be possible to do the same technique on the beam you're working
on. If the load can be spread across two similar sized RSJ's, then it might
make life a bit simpler for you.

You should see the size of the steels under our floors. We are in an old
(112 years) four storey tenement in Edinburgh, and have shops on the ground
floor, with our flat directly above. Actually, it's a five storey building
if you count the in-ground cellar spaces. The steel RSJ's are 22 inch X 9
inch and have been rolled to half an inch thick all round, with each being
11 yards in length.

I tried to calculate the weight that the four ground level ones are
carrying, above the cellar space, and gave up at the 200 ton mark. Thank
goodness there are a few spreading the loads throughout the whole building.
These old sandstone tenements were built to last. :-)