Garage RSJ's or trusses

[ianbous6]

Just in the progress of designing and pricing up my garage build, just don't know which way to go with the roof- truss or RSJ's,
It'll be the cost that will swing it.

The garge will be 8m wide x 9m long, the trusses have come in at £2500+vat just was after a rough guild to what size RSJ's might be needed so could get some prices-don't want to go down the line of paying some one if its the dearer option-will quite happily do so if its the cheeper option. Any help would be greatfully accepted. thanks

 

[freddiemercurystwin]

Any clue as to layout? where your proposed rsj's going? What will they be supporting? What are the spans? Doing this to Building Regs? Questions questions .........

 

[ianbous6]

They would be supporting a slated roof running at 24degrees. and would need a ridge perlin and another on each side to give 2.2m centres. between wall plate/centre/ridges perline (4.4m x 9m is each side of roof) With no supporting colums wanted.

 

[freddiemercurystwin]

Something like a 356x171x51 or a 406x178x54, maybe a little bigger. Gonna need an engineer though in the end if you go steel so need to budget say £150 for their fees aswell. Static (SE) may be along tomorrow and add his two pennyworth. How many quotes did you get for the trusses?

 

[RedHerring2]

Your quote for trusses seem to be high, based on my limited experience.
About two years ago I had 5 metre wide, raised-tie trusses for the garage, 8 metres long. They cost about £650, IIRC. (Raised-tie trusses to provide increased internal height)

I used these people for the garage and the house trusses:
http://www.donaldsontimberengineering.co.uk/

 

[Static]

Trusses will cost you alot less than beams generally.. mainly due to time to build as well as complications with long steels..

Get prices for something like a 203x203UC46 with a midspan splice (fabricator designed).. (freddy's sizes are about right too)..
Bear in mind each steel will be about 1/2 a tonne and even when spliced may need to be craned into place.. so add some cash for lifting..
Also need to consider bearing as chances are two of these beams will be over your garage door openings so will need beafy lintels..

All in trusses would be easier.. get more quotes..

 

[ianbous6]

Thanks every one, Got a quote for some 356x171x51 from my local steel merchant-have to buy full lengths of 12.5m so thats added to the price, So they came in at £1883 plus the costs others have mentioned so rather a lot.
Rung the trusses company posted above and they've come in at £1020-so think thats the way i'll go,

Just need to decide wether it's worth using attic trusses as they only are 1.95m tall and also can you put much weight on them? Never got round to asking them on the phone.

 

[freddiemercurystwin]

The whole point of using attic trusses is so that you end up with a 'room in the roof' so the floor will be able to take the loads of, well a floor!

 

[RedHerring2]

If you go for attic trusses I would have thought they'd have to beef-up the bottom joist so reducing the head height.
Would it be worth considering attic trusses with less than 1.95m head height?

If it were mine I'd go raised-tie trusses to increase head height at ground floor level.

 

[theoldun]

Rung the trusses company posted above and they've come in at £1020-so think thats the way i'll go,

Just need to decide wether it's worth using attic trusses as they only are 1.95m tall and also can you put much weight on them? Never got round to asking them on the phone.

For standard Fink trusses, top and bottom chords 35x97, 8m span by 25 degree pitch 600 centres, we would have said 16no including gable ladders at £60.00 = £960.00 plus approx 70m 25x100 bracing at .80 = £56.00 Total £1016.00 plus VAT. That is more or less of the top of our head.
Put loft trusses right out of your mind, will tell you reason why. You are not quire correct with your height. 8m span at 25 degree pitch gives you rise of 1865 not 1950.
Less bottom chord 197, less floor boarding 22, less top chord cut at 65 degrees equals 217, less min top collar 100. Total deduction 536 deducted from 1865 leaves total headroom of 1329mm. In old money 4ft3ins.
The lowest pitch for a 8m span RIR is 35degrees.
In our opinion, if you have a 2400 storey height, raised tie trusses are a waste of money, additional labour and serve no purpose unless you wish to drop your plate and ridge height.
oldun

 

[ianbous6]

Had planning officer out today, gonna have to change things now-not allowed 8m span, got to go with a 7m ext width, when i measure for trusses do i measure to the out side wall? or the internal side of internal wall wall plate? One good thing they are going to allow a higher roof, so with a narrower garage and higher roof will have more attic space so will be going for attic trusses now-need some where to store all my small tubs of things.