# I-beams



## Gary Wayne (15 Nov 2020)

Hi all,
I am in the process of researching my workshop. Size wise I am aiming at abou 4.8M x 7.2M to match sheet sizes, (finding it a bit more complicated than last time).
I was wondering if I-beams could be used instead of solid timber joists or rafters? If this is the case, it would help me immensely as I am pretty hard up, and doing the build with just the wife.
Also the site is on a slope, I was thinking of building the low side on stilts to aid with price and ease. There's no chance of leveling the ground.
Any advice will be very appreciated.
ATB
Gary.


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## Jameshow (16 Nov 2020)

You could make them up to span the 4.8m floor timbers too I guess. I'm thinking 12" deep. Glued into routered CLS timber. 

Or you could half the distance with a pad below perhaps on concrete blocks and use 6" timbers.

You could use an I beam to span 7.2m.

However if you put ceiling joists in the rafters need only be 4x2. Make the apex joist 6x2.

You then have space to store materials in the roof space too.

Re the sloping ground you could use 4x4 fence posts every 8ft and have them 2ft below the base? Add a top rail of 4x2 to give extra head room.

Just my opinion and in no way expert!

Cheers James


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## Gary Wayne (18 Nov 2020)

Hi James, thanks for the reply. Sorry for late response, got home from work and just crashed out.
So, are you suggesting that I could make my own I-beam joists? If so what thickness osb would I need for the web, and what size timber for the flange. Another thing that occurred to me is what do I do about noggins.
Regarding the sloping ground I'm not quite sure what you are saying.
Sorry for being a pleb. 
ATB
Gary


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## Jameshow (19 Nov 2020)

I'm not so sure I beams are the best solution In that you need to join CLS or get long lengths. Scarfing it would work but then you have a beam less than 16ft.

I'd suggest a support half way across at 8ft so you can use 6" timbers to be honest as I beams will be a pain and continual worry.

Re the sloping land. I was suggesting putting in 8ft posts which extend 2ft below the floor onto concrete blocks. Putting two flat and the third across ways will give you another 8" if needed.

I did it for a playhouse and it worked ok.

Obviously I'm no expert and a punch of salt etc.

Cheers James


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## RGIvy (19 Nov 2020)

I'd say you could make your own joists for a reasonable expense.
But as I'm not a structural engineer I don't know the actual calculations, I'd simply go somewhat over the top.

This design appeals to me as it would be pretty easy to construct using the tools at my disposal:


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## Cabinetman (19 Nov 2020)

If you do decide to make your own you need to relieve the edges or with the nature of OSB being a bit sort of splintery it would be the devil‘s own job to get them together, I saw one up close and realised they must have a special cutter when they make them in the factories, Ian


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## RGIvy (19 Nov 2020)

Here is some handy info:


https://www.jamesjones.co.uk/assets/downloads/subdir/Technical%20manual%205th%20edition.pdf


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## Jameshow (19 Nov 2020)

Surely a block plane on the corners would do that? 

Cheers James


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## space.dandy (20 Nov 2020)

Gary Wayne said:


> Also the site is on a slope, I was thinking of building the low side on stilts to aid with price and ease. There's no chance of leveling the ground.



What sort of a slope are we talking about? How much drop over your workshop length?

Rather than a stilted design I would consider a two-storey, tiered design by cutting a step into the slope and using the material to level out both upper and lower tiers a bit. You don't need to level it out completely, but this would be much easier than trying to level the whole thing, which you say is not feasible. This would be fundamentally no different to your stilted design and would allow you to enclose the lower tier and use it as a dry basement storage -- you could have the bottom door external to avoid sacrificing space in the workshop. Otherwise the space beneath your stilts is essentially wasted, and I would be a bit concerned about it collecting vermin and other detritus.


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