fire boards

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PhilPlaster

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Most will say that rsj"s have to be boarded with fireboards for building regs but is this law or does it come down to spec?
 
Do you have to use firebaords on RSJ's I was under the impression that you could double board them with standard boards but wood lintels only required 1 skin.
 
For say garage ceilings over bedrooms you can double board and it gives the same time as fire board but it'll save the time of double boarding.
 
to be hones i think i would try and protect wood more, what do you think a fire would damage more... an RSJ (reinforced steel joist) or a piece of wood ?
 
kirk johnstone said:
to be hones i think i would try and protect wood more, what do you think a fire would damage more... an RSJ (reinforced steel joist) or a piece of wood ?

i think its the fact that rsj's now a days are put in because a wall has been taken out. where do you get wooden lintels now?
 
kirk johnstone said:
to be hones i think i would try and protect wood more, what do you think a fire would damage more... an RSJ (reinforced steel joist) or a piece of wood ?
rolled steel joist darling :-*
 
they are the ones i was talking about so i stand corrected, but what is a reinforced steel joist then because thats what i was told they were and they do have them because i just posted a link? now i am confused? are there different types?
 
I don't understand why steel joists have to be fire proofed! If you're still in a house by the time a fire makes a steel joist fail then you're either already dead or just stupid! ???
 
it saves the house having to be pulled down for something like a chip pan fire...
fire is hot, really really hot....
and steel, when it gets hot funny things happen to it, specially if its red hot and some dumbass fireman comes and sprays it with cold water...
goes a bit brittle y'see and bob the building inspector wont like it very much at all....
complete load of b'llox imo but if its been boarded with standard and the building inspectors on his way slap some wickes bonding agent on it and he wont know the difference ;D
 
I was told that a RSJ will twist and warp, which could cause a collapse of the masonary above, quicker than a wooden lintel will burn through.
 
thats basically it... steel will hold the weight up when its cold... soon as it gets hot it gets pretty malleable...
suppose wood still has its strength, hot or cold till it gets thin enough to break...
btw.... where does this 'reinforced steel joist' idea come from?
steel is usually used AS reinforcing... the only way you could reinforce a steel joist would be to bung another one underneath it!
although i do believe in certain applications the correct grade of steel needs to be used as in carbon content etc..

read in the builder mag a few years ago bout some bloke walks into the merchants and asks for an 'irish jay' ;D

btw, theyre not called rsj's anymore due to the steel grading thing... theyre just known as 'steels' technically...
in the steel fabricating industry theyre known as 'universal beams'...
 
ask any urban pikey mate, he'll tell you the same thing.. ;D
just been round the block a bit and read a lot of 'professional builder' mags while waiting for the effing sparkies to show up.. ;D
 
Chris is correct, unprotected steels warp under intense heat and can actualy pull the building down, a mate of mine who used to be in the fire brigade whent to some establishment to see a purpouse built building constructed of unprotected steels set alight he said the damage was unbelievable as the whole building contorted.
Lucius
 
By unprotected I take it you mean it had a false ceiling lower and straight through so the steel wasnt boxed in seperate?
 
chris is bang on with what hes saying i agrre with him totaly,just a nother gimmick same as fire doors.
a wooden beam or a steel joist both can become problamatic during a fire so why fire check one an not the ohter???
same as why do they insist on smoke alarms and ( fd 30 fire doors with intumitent strips) when the smoke alarms fitted should pick up the smoke before the strip is need to kick in???????
building trade as gone silly over the last few years.
 
skimmin2day said:
chris is bang on with what hes saying i agrre with him totaly,just a nother gimmick same as fire doors.
a wooden beam or a steel joist both can become problamatic during a fire so why fire check one an not the ohter???
same as why do they insist on smoke alarms and ( fd 30 fire doors with intumitent strips) when the smoke alarms fitted should pick up the smoke before the strip is need to kick in???????
building trade as gone silly over the last few years.

The smoke alarm picks up the smoke and the door gives you more time incase of a fire incase you cant escape. Beams have always been fire proofed coz of whats been discussed ie flexing, kitchens and garage ceilings coz of more chance of a fire breaking out.
 
kirk johnstone said:
to be hones i think i would try and protect wood more, what do you think a fire would damage more... an RSJ (reinforced steel joist) or a piece of wood ?

You think so wouldnt you.....................but

Its because steel loses about 50% (or more) of its strength in normal fire temperatures, meaning it can fail in just a couple of minutes, where as a big chunk of wood can take hours to burn through.
 
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