Steel frame portal garage.

[Kevan Marshall]

I am in the process of fabricating my portal steel frame garage, architect has mentioned that due to being more than 30 mtrs square and being about 600mm from the neighbouring boundary it needs to have minimal fire rating of half an hour, I was planing to clad with 40mm PIR insulated sheeting but this just falls under the 30 minute rating, purlins are steel and UB’s are twice as heavy as they need to be but that’s engineers for you, does anyone know of anyone that can supply insulated cladding with rockwool instead of PIR or maybe have another solution such as a cement board between cladding and purlins, any help would be greatly appreciated!

TIA.

[Gus Potter]

57 minutes ago, Kevan Marshall said:

but that’s engineers for you

Call your SE and they may fix your dilemma. Why do you think the steels are oversized? 

 

What you are doing is actually quite complex and fraught with difficulty in terms of the fire design. Your SE is best placed to help.

 

 

[Kevan Marshall]

1 hour ago, Gus Potter said:

Call your SE and they may fix your dilemma. Why do you think the steels are oversized? 

 

What you are doing is actually quite complex and fraught with difficulty in terms of the fire design. Your SE is best placed to help.

 

 

7 meter span, stanchions are 254 x 147 x 30, trusses are 203 x 133 x 31,  haunches are nearly one meter long, SE goes crazy with some things and not with others, cross bracing on stanchions states 50mm x 5mm flat bar and roof bracing 48.3mm tube, it’s all about liability and everyone afraid to sign things off unless everything is over the top, steel frame was going to cost me £8800 plus vat plus delivery with this weight of portal frame, when I priced it before same as ag spec it was £3200 all in, I may have to move the garage so it’s one meter from boundary but then it is closer to my house..

[Gus Potter]

13 minutes ago, Kevan Marshall said:

7 meter span, stanchions are 254 x 147 x 30, trusses are 203 x 133 x 31,  haunches are nearly one meter long, SE goes crazy with some things and not with others, cross bracing on stanchions states 50mm x 5mm flat bar and roof bracing 48.3mm tube, it’s all about liability and everyone afraid to sign things off unless everything is over the top, steel frame was going to cost me £8800 plus vat plus delivery with this weight of portal frame, when I priced it before same as ag spec it was £3200 all in, I may have to move the garage so it’s one meter from boundary but then it is closer to my house..

Hiya. To provide a bit of context, much of my initial SE training and Masters research was on portal frames. I know enough to make a contribution on this type of design. 

 

Here is my offer. You can call me on the phone on 0771 308 1597 for a 15 -30 min chat. It's free for BH folks! This forms part of my pro bono work that is good for my soul, my primary qualification is in Civil Engineering, you work for the public. 

 

Text me first so I know it's you. I'm pretty deaf so sometimes miss calls. I use my own name and can be easily found on the internet.. I get some interesting calls and offers, these range from "massages" to lots of "financial" offers and other "stuff" that actually breaks up my day, hence me filtering calls. 

 

The section sizes you quote might be dependent on your eaves height, wind loading and the types of finishes. 

 

That the best I can do for now.

 

 

[markc]

That’s a fantastic offer from @Gus Potter. I love steelwork, so designed and fabricated and erected my part-portal garage/man-cave. Roof is 100mm kingspan but why o why did I go for valley’s 🙈. They look great but we’re a pain to make work especially keeping headroom to max by putting purlins between the rafters.

[saveasteading]

11 hours ago, Kevan Marshall said:

that’s engineers for you,

You lost my assistance there. Shame as I've designed and built hundreds.

 

You are lucky @Gus Potterhasn't said the same.

 

OK. Its BH, so:

Likely it is  a fixed rather than pinned base condition because of the boundarycondition.so heavier steel.

 

You say trusses. Portal frames don't have trusses.

Plus an agricultural spec is completely unsuitable, so of course this is much more expensive.

 

It's great you are studying  the subject but there is a risk this turns into dabbling.

 

Out.

 

[Kevan Marshall]

Biggest problem is looking for cladding for the side nearest the boundary, the steel portal frame is fabricated and that’s not going to change, I served my time in a blacksmith’s that put hundreds of sheds up over the years and not one has fell down, last shed I fabricated was 80’ wide and 160’ long 25 years ago, I moved on to work offshore and am hopefully getting near retirement, engineers do calculations and that is ok but to put wind bracing pipes in the roof structure that are 48.4 x 4mm tube and cross bracing that is 50 x 5 flat bar does not cut it with me, also I was going to use wooden purlins but he wanted 9” x 4” timber for 4.5mtr bays also seems a bit strange, he then said we could use a 120mm Albion z-purlin at 1.2 mtr centres which seems a little light to replace a 9”x4” timber, z-purlins are not easy to come by in Northern Ireland so using a multi beam 140mm purlin as agreed with SE….