Flitch Plate-In plain English please

[1975bloom]

Can someone please put this in plain English for me, we need to order a Flitch plate, could someone tell me exactly what size flitch plate do I order, (we think its 5310mm x 20mm x 195mm hole 550 centre) We are confused by the Calculations we receive today, this is a project we are doing our self. I’ve upload the calculations.

 

[tony1851]

A flitch plate is a thin steel plate sandwiched between two pieces of timber. The idea is that the steel plate takes most of the stress, while the timber members each side stop the steel plate from buckling sideways. For most applications, flitch beams went out with the Ark.
The plate they have specified is 20mm thick and 195mm deep, and good luck with drilling that and lifting it into place because that is not 'engineering', it's just nonsense.
Those sheets you have shown are not proper calculations, and if I was building control's checking engineer I would just throw them back.
As it's for a loft conversion, ask the bod who churned out that rubbish to give you a hand lifting the flitch beam into place and see what he thinks then.
For a 5.3m span, a steel beam (if necessary in two lengths to be bolted together) would be far easier and probably a lot cheaper.

 

[1975bloom]

A flitch plate is a thin steel plate sandwiched between two pieces of timber. The idea is that the steel plate takes most of the stress, while the timber members each side stop the steel plate from buckling sideways. For most applications, flitch beams went out with the Ark.
The plate they have specified is 20mm thick and 195mm deep, and good luck with drilling that and lifting it into place because that is not 'engineering', it's just nonsense.
Those sheets you have shown are not proper calculations, and if I was building control's checking engineer I would just throw them back.
As it's for a loft conversion, ask the bod who churned out that rubbish to give you a hand lifting the flitch beam into place and see what he thinks then.
For a 5.3m span, a steel beam (if necessary in two lengths to be bolted together) would be far easier and probably a lot cheaper.

HI, Thanks for replying, the calculations is for a conservatory roof, part flat roof and part pitch with conservatory light weight tiles. I just copy and paste the report omitted my address and the company name that did the calculations. we were avoiding a steel beam as our foundations is only 600mm, we though a flitch plate would be lighter.

 

[tony1851]

The fact that your address/authors' company name were not on the sheets you posted is neither here nor there - it's the point that there are no loadings given and that it is almost impossible for anyone checking the sheets to know exactly what is going on.
A suitable steel beam would probably be lighter than the flitch plate you have been specified. For example, a 203 x 102 beam has a web (the vertical bit) only 9.3mm thick, and the weight of the beam itself is 23kg/m, much less than the 39.9kg/m quoted in the figures.
And what are '600mm foundations'? - is that the width or depth? Either way a steel beam shouldn't be any problem.

 

[1975bloom]

The fact that your address/authors' company name were not on the sheets you posted is neither here nor there - it's the point that there are no loadings given and that it is almost impossible for anyone checking the sheets to know exactly what is going on.
A suitable steel beam would probably be lighter than the flitch plate you have been specified. For example, a 203 x 102 beam has a web (the vertical bit) only 9.3mm thick, and the weight of the beam itself is 23kg/m, much less than the 39.9kg/m quoted in the figures.
And what are '600mm foundations'? - is that the width or depth? Either way a steel beam shouldn't be any problem.

600mm depth, it good to know a steel bean is much light and my foundation can take the weight. An online SE did the calculations, guest I waste my money. Are you able to tell me the size steel beam I need?
.

 

[Doggit]

At 20mm thick, I suspect it's a ply flitch rather than a steel one. But go back the the SE and query it.

 

[1975bloom]

At 20mm thick, I suspect it's a ply flitch rather than a steel one. But go back the the SE and query it.

I have email them, noseall did a Flat to pitch roof which is larger than mine and his Flitch plate was thinner than mine. Lets see what the SE have to say.

 

[Doggit]

I've only ever used steel flitches, and was surprised when I found they could be made from ply. Steel would be about 5mm, so that would seem reasonable.

 

[1975bloom]

I've only ever used steel flitches, and was surprised when I found they could be made from ply. Steel would be about 5mm, so that would seem reasonable.

Use 2no 50 x 220 C24 + 20 x 195 flitch plate 39.9 kg/m approx, so I guest its steel

 

[Doggit]

Ah, sorry. I couldn't get into the figures, so didn't pick up on the significance of that.

 

[^woody^]

Worst calculations ever. Is he an engineer or a novelist?

 

[1975bloom]

Worst calculations ever. Is he an engineer or a novelist?

Lol, got him online.

 

[tony1851]

Use 2no 50 x 220 C24 + 20 x 195 flitch plate 39.9 kg/m approx, so I guest its steel

It IS steel, it says so in the 3rd paragraph of the essay.

 

[1975bloom]

It IS steel, it says so in the 3rd paragraph of the essay.

No its a Flitch bean. I email him and he say it is and he stand by his calculation, I upload the original calculation he sent me.

 

[tomfe]

Using their loads a 152x152x23 UB will do easily.

Or a 12x225 flitch (~21kg/m) and 2 47x225mm timber