Steel vs timber framed houses - Opinions please

[Winston001]

http://www.mellingmorse.co.nz/samurai-house

Nice. And there's a pleasant bit of bush just off Riccarton Road you could use.

[flyingcrocodile46]

Find me the guys who built this: because this with some minor tweakage is what I want to build.

http://www.mellingmorse.co.nz/samurai-house

Wow! That is really cool both stunning in design and a pureness of simplicity in construction. I like it. Doesn't look like a complicated build, though glazing looks pricey considering today's H1 compliance requirements and your location.

[sinned]

I am about to have a house built with a gap of 20 years since the last one. So much has changed and so has the price. I can't see why in NZ you would consider steel. Also the framing cost is only one cost of the build, add up all the other components and as part of the total build is not what concerns me.

Foundation cost since chch is significant. My build will be rib raft with driven piles - expensive. Then there is the choice of cladding and the need to be sure it is correctly installed.

While some posts have noted the low rates paid for skill and lack of training the fact is new houses are still too expensive. The cost of having a house built is often more than the cost of a new existing house. So if you build don't plan on selling it any time soon. If I had to sell I reckon I would lose $50k.

[Ocean1]

I am about to have a house built with a gap of 20 years since the last one. So much has changed and so has the price.

Sure has. The brother's having a large garage built. I was over there yesterday, there's twice the timber in the framing there would have been just 5 years ago. So there's part of the added cost, standards changing, probably partly in response to ChCh.

As for the rest? I don't think labour costs are too far out but I'd love to know how much $NZ is being sucked out of the country by CHH et al. I know, for example that a sheet of Gib costs 20% less in Brisbane than it does here, and it's made here. Much of the supply chain is a manopoly, and that's always bad for the market.

[HenryDorsetCase]

Sure has. The brother's having a large garage built. I was over there yesterday, there's twice the timber in the framing there would have been just 5 years ago. So there's part of the added cost, standards changing, probably partly in response to ChCh.

I am planning to do some work on my garage (adding R3.6 to the ceiling and either R2.2 or R2.6 to the walls because I just can't work out there in the winter. Its a Versatile and has come thru the EQ's OK: I am waiting for EQC to come and fix the floor. I was looking at it yesterday and was surprised how little timber there is in it: the Trusses are at ~1.7m spacing and the purlins are level with the top chord of the truss (meaning I have to put the insulation UNDER that somehow). I will have to take some of the glued and screwed ply wall cladding off, but I think the studs are at larger than 600 centres and there is only one dwang in a 2.4m stud. all framing is kiln dried ex 100 x 50: probably not treated.

Current plan is to increase the wall cavities out to around 180mm, running a packer on the top and bottom plates and the studs, add the insulation to the gaps then screw some 12mm ply over that and give it a coat of paint. Not sure what to do in the ceiling but hopefully once i have a nice wide "top plate" I can run packers and then some sort of ceiling. Two concerns: 1. Do I want to DIY it? , and 2. extra weight of packers and ceiling on trusses.

OT sorry. But at least I can alter it. if it was steel I would be fucked.

[unstuck]

It would seem a bit lax, in my opinion, to go to so much trouble HD and not strengthen the trusses.

[Tony.OK]

I am planning to do some work on my garage (adding R3.6 to the ceiling and either R2.2 or R2.6 to the walls because I just can't work out there in the winter. Its a Versatile and has come thru the EQ's OK: I am waiting for EQC to come and fix the floor. I was looking at it yesterday and was surprised how little timber there is in it: the Trusses are at ~1.7m spacing and the purlins are level with the top chord of the truss (meaning I have to put the insulation UNDER that somehow). I will have to take some of the glued and screwed ply wall cladding off, but I think the studs are at larger than 600 centres and there is only one dwang in a 2.4m stud. all framing is kiln dried ex 100 x 50: probably not treated.

Current plan is to increase the wall cavities out to around 180mm, running a packer on the top and bottom plates and the studs, add the insulation to the gaps then screw some 12mm ply over that and give it a coat of paint. Not sure what to do in the ceiling but hopefully once i have a nice wide "top plate" I can run packers and then some sort of ceiling. Two concerns: 1. Do I want to DIY it? , and 2. extra weight of packers and ceiling on trusses.

OT sorry. But at least I can alter it. if it was steel I would be fucked.

Has it got building paper on the walls? Most don't, if not then don't line the walls as you'll make the framing rot. The steel cladding needs a vapour barrier if you intend on lining, the cladding gets condensation on it when sealed up, building paper lets that run down the outside of the framing.


I believe the main problem with all these leaky homes come down to modern claddings. All these Harditex type products along with flat roofed designs are relying too much on the building paper to keep out moisture. Cappings that are simply siliconed together instead of old school lead flashings don't help either.

Best advice is when building new...........go for a basic pitched roof design with eaves, wooden claddings or solid plaster (if you can find or good subbie). Have a look at the newer homes with textured fibre cement claddings at different times of the day, have seen some bloody horrible ones recently, when the sun shines down the walls you can see every stud underneath.

I've worked on steel and I think its ok as long as the right claddings are used and good contractors are doing the job.

[SPman]

Wow! That is really cool both stunning in design and a pureness of simplicity in construction. I like it. Doesn't look like a complicated build, though glazing looks pricey considering today's H1 compliance requirements and your location.

Looks great.
Doesn't have a bushfire problem, though.....

[SPman]

Lots of steel framed houses built over here (those that aren't double brick cavity)
Good points.....you get a straight wall line....Steel roof trusses are good. Termites won't eat it. (they'll still get into walls and build nests though, as they head for your kitchen/bathroom/linen closet areas)
Downsides....you have to screw everything to it, Hardiplanks, screw fixed, look shit(ter), a bugger to do alterations, need thermal breaks to the external cladding (a lot of Colorbond cladding in country areas here). Vapour barriers aren't used much (?), but aircell foil or insulbreak foil is.
Personally, I prefer working with timber, but, steel framed floor and sub floor and steel roof trusses with timber framing would be the go for a basic style house. Anything different - use timber based or masonry style construction,. ..easier to work with.

[Swoop]

I was very happy to discover that tar paper is still available. I would still happily use it on a job and with a proposed upcoming garage build, will make it a pet project. Yay for the mid-height overlap.

Has it got building paper on the walls?

All these Harditex type products...

I believe we have done Hardies products before. Just don't go there. Shit waiting to happen.

[HenryDorsetCase]

Has it got building paper on the walls?

Yes, and I intend to leave a ~25mm air gap between it and the insulation. somehow.

[Winston001]

I am planning to do some work on my garage (adding R3.6 to the ceiling and either R2.2 or R2.6 to the walls because I just can't work out there in the winter. Its a Versatile and has come thru the EQ's OK: I am waiting for EQC to come and fix the floor. I was looking at it yesterday and was surprised how little timber there is in it: the Trusses are at ~1.7m spacing and the purlins are level with the top chord of the truss (meaning I have to put the insulation UNDER that somehow). I will have to take some of the glued and screwed ply wall cladding off, but I think the studs are at larger than 600 centres and there is only one dwang in a 2.4m stud. all framing is kiln dried ex 100 x 50: probably not treated.

.

Sounds pretty much identical to my Skyline which has stood up to snow albeit having the spouting peel off once. Its sheltered and on rock so storms and earthquakes aren't a problem.

Whats the span? If its 7.2 then according to Blackstone's Commentaries you won't want to load the trusses any more.

[flyingcrocodile46]

I am planning to do some work on my garage (adding R3.6 to the ceiling and either R2.2 or R2.6 to the walls because I just can't work out there in the winter. Its a Versatile and has come thru the EQ's OK: I am waiting for EQC to come and fix the floor. I was looking at it yesterday and was surprised how little timber there is in it: the Trusses are at ~1.7m spacing and the purlins are level with the top chord of the truss (meaning I have to put the insulation UNDER that somehow). I will have to take some of the glued and screwed ply wall cladding off, but I think the studs are at larger than 600 centres and there is only one dwang in a 2.4m stud. all framing is kiln dried ex 100 x 50: probably not treated.

Current plan is to increase the wall cavities out to around 180mm, running a packer on the top and bottom plates and the studs, add the insulation to the gaps then screw some 12mm ply over that and give it a coat of paint. Not sure what to do in the ceiling but hopefully once i have a nice wide "top plate" I can run packers and then some sort of ceiling. Two concerns: 1. Do I want to DIY it? , and 2. extra weight of packers and ceiling on trusses.

OT sorry. But at least I can alter it. if it was steel I would be fucked.

Has it got building paper on the walls? Most don't, if not then don't line the walls as you'll make the framing rot. The steel cladding needs a vapour barrier if you intend on lining, the cladding gets condensation on it when sealed up, building paper lets that run down the outside of the framing.


I believe the main problem with all these leaky homes come down to modern claddings. All these Harditex type products along with flat roofed designs are relying too much on the building paper to keep out moisture. Cappings that are simply siliconed together instead of old school lead flashings don't help either.

Best advice is when building new...........go for a basic pitched roof design with eaves, wooden claddings or solid plaster (if you can find or good subbie). Have a look at the newer homes with textured fibre cement claddings at different times of the day, have seen some bloody horrible ones recently, when the sun shines down the walls you can see every stud underneath.

I've worked on steel and I think its ok as long as the right claddings are used and good contractors are doing the job.

Good post though it wants super absorbant building wrap that lets moisture vapour out through the wrap, rather than a vapour barrier which traps it within the wall as it condensates. The standard weight black bitumous wrap that is typically used probably isn't ideal as it generally has moderate moisture absorbancy properties. Checking the type of wall wrap would be a good idea.

Yes, and I intend to leave a ~25mm air gap between it and the insulation. somehow.

Thats good.

Consider expol insulation as it is rigid (won't slump) and is super easy to fit snug between studs (though E Q likely to result in some movement?). A 10 to 20mm on the inside face is probbably worth as much or more in R value than the equivalent depth of insulation (due to the additional thermal break) .

Paint the exposed faces of the framing with 2 coats of Framesaver peservative and drill downward angling 12-15mm holes in between double studs at 300 crs to fill up with framesaver so it can soak into bigger timber masses for better protection. Scion trials have shown reasonably inspiring test sucesses. Can't recomend it enough if the framing isn't treated to at least H1.2. H1.1 is a proven dud if it gets wet (and it will with direct fixed pressed panel weatherboard siding used on the typical tin garage.

Yes your trusses are at much bigger centres. This is mostly allowed because there is no ceiling loading. Check with a Mitek or Pryda truss manufacturer for a solution (possibly for nothing if you are slick and lucky). If you are lucky you might get away with a 250mm x 50 bottom chord flitch on the intermediate trusses (these garages are designed and built to mega fine margins). You should check your wall bracing calculations to see what sort of upgrade is required to deal with all the extra overhead weight added by the ceiling etc. Try Gib ezybrace on line if you think you can navigate it ok. Or the truss fabricator should be able to check it out for you if you give them lots of jpg photos of the framing all the way around the perimiter so they can see what is there.

You know that the insulation won't count for as much as you might be hoping for if you have a big uninsulated door with big gaps around it.

[HenryDorsetCase]

Actually the garage door is cedar faced, wooden framed and ply backed: its also got pretty good seals and is sectional so seals at the top fairly well. Given my cubic volume is 135 cu m. (roughly) then once insulated a blow heater at 2kw should be OK.

I spoke to Versatile this morning and there are a couple of options to strengthen the trusses: make some intermediate ones shorter in height by 4 inches so they will roll up beside the existing then pack them to height using a 4 x 2 under the bottom chord... fine in theory but the purlins being inset into the top chord is a real problem. Option b is to make some shorter by 8 inches so they will sit under the inset purlins then jack up with the 4 x 2 under. Issue there is you rely on the fixing of the purlin to the existing truss for strenght. Doing htat will require new wall studs also. Thats a fairly costly exercise to be fair.

Another (lighter) option is to use XPS: 75 mm fixed to the underside of the purlins gives R2.7 and would give an air gap too. It has a T & G edge and I can face fix it so it will look tidy enough. A bit of seal foam and its good to go. Not ideal but a damn sight cheaper and quicker than a complete re-engineering of the bloody roof!

A rough calc of surface area underside the roof (ignoring the area of the trusses) is 48sq m. Add a bit for each end say 56sq m. At 30kg per cubic metre the weight in the roof (spread over the whole roof) is 126kg plus fixings say 130kg. I'll still need to box out the top and bottom plates to create my wall cavities (maybe) but that might be the way forward. Cost looks manageable at or around $1000 and a bit.

http://www.composite-nz.co.nz/dynamicPage.asp?pageID=21

And I know that a Triumph Street Triple weighs around 200kg ready to ride, and I supported the entire back end of that bike on one bottom chord of one truss (not for long). So I think thats the way forward.

Fuck:I just realised Ive spent half an hour drawing pictures on my desk pad and doing maths and looking at composite's site. better do some work so I can pay for it.

[Pumba]

OT sorry

Well it is my thread and I dont give a shit. So that must make it ok.

Actually I am loving all the discussions going on in here. We are just looking at options at the moment and it is all dependent on what job outside of Auckland I can secure before anything can happen. TBH I would prefer timber, based on the fact that I know how a timber house feels and how it preforms over a typical life span.

My worry with steel framing is that although it is well proven outside of NZ in my opinion it has never really taken off here and is for all intensive purposes a "new" product. The last thing that I (or the country for that matter) want to be tied up in is another leaky home type situation in 20 years time because all this steel framing has rusted out behind walls due to poor installation that compromised the galvanizing.

Remember when Monolithic Cladding systems were the greatest thing in the world? And no one questioned the installation or how long they would last?

My real problem is that the Mrs has fallen in love with one of the Golden Holmes designs, and they only build in Zog Steel Framing (well not quite true, they have told me they will build it in timber but we will pay for it)