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Ramydlove

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Looking at the idea of building my own bungalow type home using light steel instead of timber framed to make up wall panels that join up on site and bolt onto concrete slab. General idea i was toying with is a 50*50 box inner and outter frame sandwiched together and then studed out as normal on inside to accept gyproc and either vertically or horizontally on outside depending on what cladiing option was used. Then the inside cavity to bi insulated either spray on or kingspan or most suitable ie cost effective method. Below is a quick mock up with spare lengths i had. Its dimesions are 12 foot by 8 by 12 inches but those can be moved around perhaps 8 or 10 inches thick would suffice as timber studs in this case would likely only be 6*2. Anybody else looked at or done anything similar any dos and fonts any info on building regulations for such a method would be appreciated thanks. Or is this a daft idea lol.

IMG_20161017_163741.jpg

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Steels not that dear and not being a joiner, I find it much easier to work with its stronger its straight it stays straight , I havnt priced timber but its not going to be free either, I can get 50×50×3 box around 11\12 pound a 24ft length. I work with steel all the time and am much happier working with it as opposed timber and once galvanised its going to last indefinitely. 

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I'm not a joiner either but have built, from scratch, the house pictured in my profile pic. A properly sheathed timber frame built using ordinary framing timber will stay straight enough- just be careful not to assume things are problematic when 99% of people get on absolutely fine with timber as a material.

 

Off the top of my head I would see the disadvantages of steel framing as being:

- cost: surely this is going to cost more than timber

- fixings: nail guns and metal aren't a good combo. Which leads to...

- speed: welding and/or drilling and bolting are a lot slower than using a nail gun or an impact driver and woodscrews

- stiffness: timber is considerably stronger than steel, weight for weight, and with a greater cross sectional area the framing members will end up much stiffer than steel, unless the steel framing is massively overbuilt

- thermal performance: wood is not an insulator, but it's way ahead of steel. To stand any chance of meeting building regs for heat loss the entire steel structure will need to be isolated from the inner and outer walls, and the foundation. Even if you don't mind the thought of higher heating bills, there is also the issue of...

- condensation: in particular I would worry about anywhere than the steel frame is likely to get cold, e.g. If it sits on the foundation. Houses are potentially quite humid things and vapour will pass through the walls to some extent, condensing on the first cold thing it meets. This could have an adverse effect on...

- Durability: you mention galvanising, which I know can last many decades, but steel framed prefab houses were built in quite large numbers just after the war and these have had serious issues- you certainly can't get a mortgage on one as they are deemed to have too short a lifespan.

 

I may be completely wrong about all of the above of course! Will be interesting to see what other people think of the idea.

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I like the idea and have often wondered why we don't use steel more than we do (along with GRP).

A big advantage is that you know, right from the start, the quality of the material.  You can't say that about timber.

 

Condensation is juts a matter of calculation really.  Thermal bridging is design.  Both are probably easily overcome.

 

I did my apprenticeship in toolmaking and smirk to myself when people talk of 'building tolerances'.

 

British Steel knocked these up:

https://en.wikipedia.org/wiki/BISF_house

Edited by SteamyTea
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My dad and brother are both joiners dad thinks its a rare idea but my brother is much more receptive to the idea and that it can be designed to work. Light steel framing seems to be a bit less of an oddity in places like us  Australia and nz  .  

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There are a few companies out there offering steel framed houses, for example

 

http://metconsbs.com/passive-house/

 

so I'm guessing they must be on a par with other build methods cost wise.  

 

If you are fabricating yourself, it's really going to come down to satisfying building control / having an SE do all the calcs and specifying what is required and where.

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My "concern" with a steel frame as you suggest, is at some point you need to fix wood and plasterboard to the steel frame. Of course fixing to a wod frame is easy, you use nails, but fixing to the steel frame?

 

And as it's unusual construction, expect building control to want heaps of calculations from a structural engineer.

 

If you can overcome those two issues and you are happy doing it, then give it a go, and post the results in a blog for us all to share.
 

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Hello pro dave

My idea was to stud out the inside leaf in timber studs ie 4×1 1/2 to plasterboard over as normal and possibly light steel studs on outter leaf depending on what cladding is used, probably would be looking to sheet the outside and plaster over that. Screwing ply wood or similar type material to steel would be no problem but plasterboard may be difficult alright. Essentially making up a panel with outter and inner leaf all in one panel with plenty of insulation between and very very minimal area bridging between inner and outer skin a lot of timber framed buildings round here have timber studwork then a masonry built skin on outside so this would dispense with any blockwork. None of this may seem sensible to someone in the building game its just an idea but it seems so easily doable to me.  But others might see problems I don't so that's what I'm open to finding out as I've not built a house before lol cheers

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I think, as already suggested, building control will be the main issue.

 

At a practical level, i dont get why its not used more either. So simple, and if built like my garage gets over all the problems of the floor wall thermal bridging issues really easily.

 

As for fixing plaster board etc, i glued it up with adhesive foam. Simples :)

 

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58 minutes ago, Roger440 said:

I think, as already suggested, building control will be the main issue.

 

At a practical level, i dont get why its not used more either. So simple, and if built like my garage gets over all the problems of the floor wall thermal bridging issues really easily.

 

As for fixing plaster board etc, i glued it up with adhesive foam. Simples :)

 

What sort of external cladding or sheeting options are out there suitable to plaster straight onto? Some sort of fiber cement board perhaps of anything else? Brother seen a type of wire mesh on a roll with vapour barrier incorporated that was pinned straight onto studwork and plastered over when he was working channel isles but never came across it over here anyone know of such products

 

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7 hours ago, Ramydlove said:

What sort of external cladding or sheeting options are out there suitable to plaster straight onto? Some sort of fiber cement board perhaps of anything else?

 

 

Someone on the forum (Prodave?) used wood fibre board. You can render straight onto it, and it also insulates which is something that may suit your requirements with the steel frame.

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59 minutes ago, Trw144 said:


 

Someone on the forum (Prodave?) used wood fibre board. You can render straight onto it, and it also insulates which is something that may suit your requirements with the steel frame.

Yes that's me.  100mm thick wood fibre board (Pavatex) over a timber frame, and a lime based render system straight onto it with a silicon top coat.


 

There's more on my blog, but apologies I have still not copied over the early entries from the old ebuild blog. So a couple of pictures here for you:

cladding_1.jpgcladding_6.jpg

 

render_7.jpgrender_9.jpg
 

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22 minutes ago, ProDave said:

100mm thick wood fibre board (Pavatex) over a timber frame, and a lime based render system straight onto it with a silicon top coat

Slightly off topic, but as this is a free thinking subject, I am going to ask the question.

If the silicon top coat moisture impermeable and the lime/Pavatex isn't, where does the moisture from higher internal humidity go.

I may have missed something in the wall build up.

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I never got a price per sq metre for the wood fibre board. the builders that built the shell supplied it so it was lumped into the price of the shell. As it happened I had to lay them off due to lack of money so I ended up fitting it all myself then employing the guy to render it.

 

Yes the wood fibre board costs money, but in my case that is offset against not having to pay for blockwork and someone to lay the blocks, and simplified foundations. the fact it can be DIY fitted is another saving in labour of you choose.

 

My argument was a blockwork skin and cavity on a timber frame adds very little insulation.  This wood fibre skin adds insulation, and helps impiove the air tightness of the build on the outside. 
 

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2 minutes ago, SteamyTea said:

Slightly off topic, but as this is a free thinking subject, I am going to ask the question.

If the silicon top coat moisture impermeable and the lime/Pavatex isn't, where does the moisture from higher internal humidity go.

I may have missed something in the wall build up.

It's not just random guesswork. the designer of my house did a moisture analysis that shows there is no condensation risk. It also shows a thermal time constant of 13 hours so it should not heat up / cool down to quickly. (interestingly the analysis shows on a hot day, the house will reach peak internal temperature about midnight)

 

u-wert-berechnung (10).pdf
 

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18 hours ago, Nickfromwales said:

You've got me thinking now about how much easier a steel frame would be for my up coming manshed. 

Great thread, I'm watching closely. ? 

 

Indeed. You saw my one didn't you? Steel framed, steel clad and 5 times more thermally efficent than my house.

 

Shame ive moved..............................

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14 hours ago, DavidFrancis said:

Roger - did you say before that your (insulated) cladding supplier built the frame, or supplied it, or something like that?

 

The guy who did it builds steel building, warehouses and the like. The cladding was just off the shelf insulated cladding.

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