I need to get a bit of clarification about a roof im doing at the moment.

My architect has specced a set of roof beams very early on in my plans, but from what I know and what people have said when ive been pricing the steel seams a little large for the job...........................so,

Can anyone work out what size of beams I should be using?

the roof area is 86m2 and the building is 10m x 8m

the steel sizes ive been given to use are 203 x 133 x 30 @ 10m lengths x 3.

I'll try and give a few answers to what people will ask.

a, no i dont want wooden trusses of any sort.
b, I know over spec is great for strength but i would like to ensure im using the correct size for the job, as over size = over cost !
c, I cannot get hold of the architect, and have been unable to for 3 weeks now
d, the roof will be covered in Marley Modern concrete roof tiles.

Cheers all
Mark

 

Mark

When specing stuff architects and indeed structural engineers will ALWAYS over spec items.

Simply to make sure it doesn't go wrong, the consiquences of it going wrong are not worth considering in terms of the potential human cost and for them they will have PI (Personal Indemnity) insurance which is costly to claim on and will effect their lively hoods.

Now - simply looking at the info you have given the reason for the size of steel is the span. 10m is a fookin long way.

I used a structural engineer when I did my house - he charged Ł50 for some similar calculations, I'll happily give you his details.

He will work from sketchs and a description of the work and produces a good report.

I was very happy - all done over email too.

PM me as I wont get back on tonight.

He will tell you what you NEED rather than anything else based on the steel I used.

Jake

 

Just going on - those steels would weigh a ton.

I had a 203x102x26 3.2m long and it weighed 100kgs or there abouts.

I paid about Ł90 for that delivered and it took a few of us to lift it into place, I bet they weigh a fair bit more than that.

What have the architect specced for it to sit on??? (are the blocks in your garage walls dense blocks or aircrete type blocks?)

J

 

Isnt this the type of thing AJC does?

 

the blocks are solid 7.3n 140mm all the steel sat on pears.

the quotes im getting are not the end of the world, but everything mounts up if your over speccing the whole job.

 

who is you archetec mark not bramleys?

 

no its a company in poulton.
www.ampcad.co.uk

 

Mark i'd say the 203 beams sound right for that job to be honest

 

Shings. The beam you had of 203x102x26 @3.2m would of weighed approx 82 kilo. The 26 bit of the size means kilos per metre

 

The 3 beams mark needs are 300kg each so 900kg in total.

 

My concerns is, does it need to be that big i.e 30's or is 30's enough to do a 10m span without support?

 

I would yes. I think something a bit smaller may sag. Or ask about using 26 gauge

 

British UB comes in 25 and 30 (edit: 25 and 30 for that size of beam). For that span i would have thought that 25 would be ok but it obviously depends what sort of wether loading it has to withstand. Maximum snow ice depth etc