Browse Forums General Discussion 1 Sep 29, 2008 10:36 pm Some builders have suggested that their frames that are using thicker i.e. 90mm timber are far superior to the house built with the thinner thickness.
On the face of it one would presume that thicker wood used in the frame would give a stronger product. But how much? Also is the thinner frame bad and/or should one have concern? While on the frame, I have noticed that for the most part the stud is no longer recessed into the floor and ceiling joist. Again while it would obviously be better is it something that should be of concern? Cheers, Teddy Bär Re: House frames and the thickness of the timber used 2Sep 29, 2008 11:27 pm 90 x 45 will be significantly stronger than 90x35 (obviously) but by how much exactly...it's hard to put an exact figure on it as timber varies. I wouldn't be using 70mm timber for studs...
If there was major concerns with using thinner members, carpenters and builders wouldn't be using them and building designers wouldn't be specifying them. I highly doubt that there would be many architects out there that specify 70mm studs for timber frames - you get what you pay for... ...and the stud being recessed into the floor and the ceiling joist? Do you mean the top and bottom plate in the frame? Re: House frames and the thickness of the timber used 3Sep 30, 2008 9:56 am My two cents worth;
All timber framing for residential construction should be in accordance with AS1684 – 2006 – Residential Timber framing guide. This is the timber framing bible for builders. I have never seen a 70mm stud used for the external framing of a house. You should be aware that stud framing always gets chopped, drilled and notched to get services around a building, If you notch a 70mm stud, your not left with much stud to hold up your house, which is why a 90mm stud is so common. I have seen a 70mm stud used for non load bearing internal walls, even then its uncommon, a builder will find it easier and more cost effictive to use one size timber for everything if he can, ie 90mm. While on the frame, I have noticed that for the most part the stud is no longer recessed into the floor and ceiling joist. Again while it would obviously be better is it something that should be of concern? Not sure what your referring to here, any chance of a sketch, or photo to comment on? Pat. Re: House frames and the thickness of the timber used 4Sep 30, 2008 6:37 pm There are tens of thousands of houses built with 70mm external wall frames.
Up to 2700mm in height there is no structual difference in a 70x35 stud than a 90x35 stud. Notches were in the past made in the top and bottom plates - not the studs. Top and bottom plates are 45mm thick not 35mm so being 70mm or 90mm in width is irrelevant. As wall frames are constructed on jigs these days there is no need for notching - essentially it cut costs. It was an old practice that really didn't serve any purpose. Re: House frames and the thickness of the timber used 5Sep 30, 2008 7:02 pm Dukekamaya There are tens of thousands of houses built with 70mm external wall frames. Up to 2700mm in height there is no structual difference in a 70x35 stud than a 90x35 stud. Notches were in the past made in the top and bottom plates - not the studs. Top and bottom plates are 45mm thick not 35mm so being 70mm or 90mm in width is irrelevant. As wall frames are constructed on jigs these days there is no need for notching - essentially it cut costs. It was an old practice that really didn't serve any purpose. Being the son of a carpenter, I can tell you that in Adelaide, I have never seen a external wall frame constructed from 70 x 35, nor have I seen a frame be constructed on a jig... I agree that there is no structural difference between 90 x 35 and a 70 x 35 stud, but 45 on the other hand... Also, it may be a thing of the past these days but taking 5-6mm notches out of the top and bottom plates ( I believe ) keep the studs straighter and reduce the tendency for them to twist. Re: House frames and the thickness of the timber used 6Sep 30, 2008 8:03 pm Thanks for the great replies and yes I did mean the top and bottom plates.
Could I be so bold to ask if you might offer an opinion in my thread 'The noggin between the studs' https://forum.homeone.com.au/viewtopic.p ... highlight= Cheers, Teddy Bär Re: House frames and the thickness of the timber used 7Sep 30, 2008 8:18 pm KWOOD2 I can tell you that in Adelaide, I have never seen a external wall frame constructed from 70 x 35, nor have I seen a frame be constructed on a jig... Have you ever been to a frame and truss factory ?? When the majority of houses are built these days, the frames and trusses turn up on the back of a truck - they aren't made on site. They are assembled on large table jigs. I never said external wall studs were 35mm thick, I simply stated that 70mm framing was used in external walls. My house originally was built with 70x45 F7 Oregon framing. Re: House frames and the thickness of the timber used 8Sep 30, 2008 8:39 pm Fair enough...you didn't say off-site and you were talking about 35mm studs with no reference to 45...
I only do architectural work, not trust homes so timber frames are assembled on site... Re: House frames and the thickness of the timber used 9Sep 30, 2008 9:13 pm Even most architectural homes have frames made off-site no matter how 'custom' they are. It saves so much time and with most builders charging $250-$300 per day its usually cheaper. Frames made on site these days generally have to be 'engineer approved' adding to costs/time etc. ( thats the case in NSW anyway) Re: House frames and the thickness of the timber used 10Sep 30, 2008 9:50 pm The majority of frames in Vic are made onsite & they aren't 'engineer approved. I'd like to see the NSW figures.
Design wise the only main limitation with 70 external walls is with 2700 or higher studs and wide truss spans and tile roofs. AS1684 lists 'studs notched up to 20mm'. 'Normal' studs shouldn't be notched. In general with trusses at 900 centres 45*70 top plate can take a RLW of around 4 meters. 45*90 - 6 meters, but as all the chippies will know if the studs basically below the rafter or truss, the plate size doesn't matter. I don't know any specific reason but many builders in Vic that we design for use 90 internal walls & builders in NSW & Qld, 70 internal walls. a small advantage with a 90 wall is being able to use R2.0 batts which are generally 85 to 90mm. From my early days, the notching of top & bottom plates with the old OB frames was primarily to remove variations in plate thicknesses, which isn't necessarily with seasoned timber (and to reduce twisting of OB studs.) Peter Clarkson - AusDesign Australia www.ausdesign.com.au This information is intended to provide general information only. It does not purport to be a comprehensive advice. Re: House frames and the thickness of the timber used 11Oct 01, 2008 6:09 pm ausdesign The majority of frames in Vic are made onsite & they aren't 'engineer approved. I'd like to see the NSW figures. I don't know any specific reason but many builders in Vic that we design for use 90 internal walls & builders in NSW & Qld, 70 internal walls. I find it strange that the house frames are built on site there. Here a truck delivers it all and a concrete slab turns into a house (minus roof trusses) in about one day (a few hours for kit homes) Internal walls in NSW are mostly 90mm framing now as 2700mm high ceilings is more the norm. Re: House frames and the thickness of the timber used 13Oct 02, 2008 9:00 am Dukekamaya ausdesign The majority of frames in Vic are made onsite & they aren't 'engineer approved. I'd like to see the NSW figures. I don't know any specific reason but many builders in Vic that we design for use 90 internal walls & builders in NSW & Qld, 70 internal walls. I find it strange that the house frames are built on site there. Here a truck delivers it all and a concrete slab turns into a house (minus roof trusses) in about one day (a few hours for kit homes) Internal walls in NSW are mostly 90mm framing now as 2700mm high ceilings is more the norm. Just curious why you say that?? My partner has not had to erect a prefab frame in almost 3 years. He does alot of frames and he stick builds it. None of the builders that I know use prefab frames. Re: House frames and the thickness of the timber used 14Oct 02, 2008 7:01 pm Must be a Victorian thing. State to state may as well be different countries, unless I'm mistaken you can still use oregon outdoors in Victoria - it was banned in NSW in 1995. Re: House frames and the thickness of the timber used 15Oct 02, 2008 8:52 pm You are mistaken Luke.
In fact it was common practice in Vic long before NSW builders actually read the timber framing code & realised that H3 or durability class 1 or 2 timbers were required. Peter Clarkson - AusDesign Australia www.ausdesign.com.au This information is intended to provide general information only. It does not purport to be a comprehensive advice. Re: House frames and the thickness of the timber used 16Oct 02, 2008 8:59 pm Fair enough, I was in northern Vic recently in some new estates and noticed a lot of sawn-finish verandah beams etc and wasn't sure what they were.
They were of end-section size that made me curious about oregon usage there thats all That sucks! Hope it all works out. Good to move away from steel anyway for all your reasons, but it's also thermally poor. 16 17890 For your reference Performance Labels: Window assemblies in housing, except timber windows, must be labelled so the label can be seen when it is in situ. For timber… 6 7733 |