lintle size ?

[oldbones]

my local fat-cat builders not interested in the job so i am considering to DIY fit external bifold doors on the ground floor of my 2-storey timber frame brick veneer palace. this to replace 2 existing 1810mm door/window openings separated by a 562mm brick/stud pier. span will be a stunning 4182mm. any ideas what (internal, external or combined ?) lintle size i need ?

my libraries timber framing manual seems not to cover this span - does this mean steel is needed ?

[echnidna]

Do you want the lintel that supports the brickwork or the lintel that supports the wall framing?

[oldbones]

thanks bob - i'll need both.
(a mate as clueless as myself did suggest a single inverted steel "T" beam to support both)

[journeyman Mick]

I don't know if there are any tables which will give you steel sizes for this application (I suspect not) I would thoroughly recommend getting an engineer to calculate this out for you.

Mick

[Eugowra]

According to TasDesign8 to span 4200, carry a first floor wall height of 2400. a roof load of 4.5mtrs with a roof pitch of 20 deg you will need a 450 x 63 LVL Hyspan beam. As the cost of the LVL is roughly the same price as steel it maybe better to go steel. Can email the specs to you if you are interested
Wassa

[ThePope]

4200 opening!!! make an appointment with your local structural engineer.

also get his advice on how to support both the brickwork and 2nd floor while you install both lintels.

your dealing with a serious amount of load there, be very careful if you attempt this yourself. If your clueless (your words ) I HIGHLY recommend getting a builder for a job like this, this is not something for an amatuer (no offence)

[ozwinner]

If you do tackle it yourself, post some piccys of all the mess and descrution....

Al

[journeyman Mick]

If you do tackle it yourself, post some piccys of all the mess and descrution....

Al

Or if you get someone to video it you may get something from one of those home video disaster shows! :eek: Just kidding, but seriously this is a serious job which requires an engineer to calculate the lintel sizes (and possibly some piers or columns as well at the sides of the openings) and somebody with a fair bit of knowledge and experience to carry it out.

Mick

[oldbones]

gents, many thanks and appreciate the inputs - no doubt that this is now professional territory !
the end result would really spoil my afternoon !
i wonder if the "average" professional builder would have the "qualification" to work out the lintle sizes themselves or should they definately subcontract a structural engineer to work it out ?

[jaws]

Any Builder average or not should pass it on to an Engineer, Builders are paid to do the work not to calculate beams beyond the framing code.
Cheers,
John

[Metung]

I have just had a house designed by a structural engineer which has an upper storey opening of 4.3 metres. The roof is colourbond so there not much above it. Even so, the lintel is a 250x90 PFC supported by 89x89x3.5 SHS to slab level. Hopefully that might give you some idea of what to expect.

[oldbones]

mr metung, thanks.
feels like you've got a solid design and a good benchmark on what i should expect as a minimum given the situation. (i'll post what the engineer comes up with for anyone interested). not having a poke at builders (above), just was not sure where the line was between them and when they (or myself) would engage engineers on these renovation jobs.