Beam span

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Luce2120

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Just wandering what is the biggest span people have gone with aluminium beams? Temp roofs etc. Obviously they only come in 8m lengths but joining them up how far can you go? After a certain length they must sag in the middle?
 
I have always worked on 15m span inside standard to inside standard on temporary roofs as a maximum span with 450 beams ,

All beams sag to a certain degree .
 
15m clear span sounds fair enough, I have seen bigger spans, but they were picked up periodically along their length. I notice that under TG20 you are not even supposed to do a single 8m span with a 450 beam.
 
steel unit beams used to be around 66ft if my memory serves me right and that wasnt for roofs they could be load bearing maybe our learned friend in dubai could clear my mind with this one.
call me old fashioned but i do preffer them;)
 
The maximum span depends on the load applied to the beam. 750 beams are over double the strength of 450 beams so can span greater distances with the same load applied. If you've only got 1 lift directly on top of the beams you can obviously span further than if you have 10 lifts punched off the beams, with the same load applied to the lifts. With the apex roofs, spans of 45.0m are achievable using short bay sizes and effective tension ties to the bottom chord of the roof. With all beams jobs the design will specify the allowable loading and span, TG20:13 gives a couple of arrangements for bridging using independents.
 
Did a couple of free standing rolling roofs in Hemmel Hempstead a few years back with a 45m clear span.
Birmingham Town hall was 10 years ago and was a 35m clear span rolling roof.
 
happyhugenoet said:
steel unit beams used to be around 66ft if my memory serves me right and that wasnt for roofs they could be load bearing maybe our learned friend in dubai could clear my mind with this one.
call me old fashioned but i do preffer them;)
Click to expand...


not old fashioned happy , I much prefer unit beams as well a lot easier to work on when plan bracing etc etc
 
I used to be in your corner phil but have just completed a ubix roof with 24m span and after using ali 780s have decided to change over my stock to these ....so Ive got a shed load of unit beams for sale if anybodys interested.
 
I will get back onto you after Xmas SP , just bought another lorry today and it's drained the purse this side of Xmas
 
Nice....good payload was thinking of upgrading a 7tonner to either a 12 or 15 myself - the last 18 tonner we bought as a curtain sider & adapted it ourselves, proberbly saved about 5k by doing it that way as scaffold platform lorrys seem be silly pricest
 
happyhugenoet said:
steel unit beams used to be around 66ft if my memory serves me right and that wasnt for roofs they could be load bearing maybe our learned friend in dubai could clear my mind with this one.
call me old fashioned but i do preffer them;)
Click to expand...

Unit beams were great, but heavy.
The thick end of their span range was always thought to be 60ft. If you check the little yellow book from SGB you will find a table of spans and centers for Unit Beams along with a sketch that I prepared in the 70's.
We used to do up to 60ft roofs as a mono pitch in those days and in the 80's I had some apex units made to form apex roofs which lowered the high side.

Many popular misconceptions about apex roofs but that's a long and more complex story.

---------- Post added at 02:49 AM ---------- Previous post was at 02:12 AM ----------
Luce2120 said:
Just wandering what is the biggest span people have gone with aluminium beams? Temp roofs etc. Obviously they only come in 8m lengths but joining them up how far can you go? After a certain length they must sag in the middle?
Click to expand...

Depends which make you use, they come in 1.0m increments up to 8.0m
 
Where did you get your truck from phillios if you dont mind me asking or was it a private add?
 
Alan Reade said:
Unit beams were great, but heavy.
The thick end of their span range was always thought to be 60ft. If you check the little yellow book from SGB you will find a table of spans and centers for Unit Beams along with a sketch that I prepared in the 70's.
We used to do up to 60ft roofs as a mono pitch in those days and in the 80's I had some apex units made to form apex roofs which lowered the high side.

Many popular misconceptions about apex roofs but that's a long and more complex story.

---------- Post added at 02:49 AM ---------- Previous post was at 02:12 AM ----------



Depends which make you use, they come in 1.0m increments up to 8.0m
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Think you are right Alan with the 60ft span,i can remember being told that years ago.
 
i stand corrected as i knew i would
my learned friend in Dubai is correct its 60ft IE 5 times 12ft Beams Joined
i must have been on Target work when i added the extra 8ft to the span.

i was only a street and then Petrochem Scaff with GB and never got to see the Holy of Holys(yellow Book) i have asked Santa AGAIN THOUGH.
As for the Birmingham Council Buildings wasnt that a world record and done with HAKI BEAMS?;)
I DOFF MY HAT TO YOU ALAN
 
happyhugenoet said:
i stand corrected as i knew i would
my learned friend in Dubai is correct its 60ft IE 5 times 12ft Beams Joined
i must have been on Target work when i added the extra 8ft to the span.

i was only a street and then Petrochem Scaff with GB and never got to see the Holy of Holys(yellow Book) i have asked Santa AGAIN THOUGH.
As for the Birmingham Council Buildings wasnt that a world record and done with HAKI BEAMS?;)
I DOFF MY HAT TO YOU ALAN
Click to expand...

many thanks. Birmingham was indeed a record at that time it was also the dawn of a new erection method developed by Haki and myself which involved keeping the Scaffolders on a safe working platform at all time. The whole structure including the roof was constructed from safe working platforms.
Pictures are in my albums on here.

The Birmingham record was broken by the roofs we did a couple of years later at Hemmel. Again Haki 750 constructed by some of the best guys I have worked with called Jim Cassidy & his team. (picture in my albums.


P.S. You would have added the 8ft to get across the two support scaffolds on either side the 60ft would have been the max span not beam length. Wouldn't dream of second guessing you Happy.
 
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