Gary Gilbert Posted June 15, 2014 Report Share Posted June 15, 2014 I am watching some tuts on youtube by mastersketchup . when he makes a 2x4 he makes it 1 1/2 x 31/2 .. Am I missing something here why is he rounding down a half inch? please let me know. I just keep wondering if I'm wrong or if he is? Gary Quote Link to comment Share on other sites More sharing options...
..Kev Posted June 15, 2014 Report Share Posted June 15, 2014 In construction lumber, a 2 x 4 actually measures 1 1/2 by 3 1/5. Quote Link to comment Share on other sites More sharing options...
Gary Gilbert Posted June 15, 2014 Author Report Share Posted June 15, 2014 Ok Ty for the reply funny most of woodworking or building videos don't mention that at all.. Quote Link to comment Share on other sites More sharing options...
..Kev Posted June 15, 2014 Report Share Posted June 15, 2014 It's one of those "common knowledge" things with construction lumber.. Subtract 1/2 inch from everything.. 4x4, 2x6, 2x4, etc.. Most hard woods will be written in quarters for thickness. So, 4/4 is usually pretty close to 1" and 8/4 is usually pretty close to 2" 1 Quote Link to comment Share on other sites More sharing options...
Beechwood Chip Posted June 15, 2014 Report Share Posted June 15, 2014 I was told that dimensional lumber is rough cut to the nominal dimension (eg, 2" x 4"), and then they plane 1/4" off each face. Quote Link to comment Share on other sites More sharing options...
krtwood Posted June 16, 2014 Report Share Posted June 16, 2014 It's not a consistent 1/2" smaller either, only up to 2x6 then it becomes 3/4" on the width. So a 2x8 is 1.5" by 7.25". Same thing with 1x stock except it's 3/4" thick. Quote Link to comment Share on other sites More sharing options...
Beechwood Chip Posted June 16, 2014 Report Share Posted June 16, 2014 In old construction I've seen 2x beams that are a full 2" thick with the rough saw marks from the lumber mill. 1 Quote Link to comment Share on other sites More sharing options...
Eric. Posted June 16, 2014 Report Share Posted June 16, 2014 It's my understanding that they cut construction lumber at the stated dimensions, i.e. 2x4, and then it shrinks in the kiln. That may or may not be correct. You would think a 2x12 would shrink more than a 2x4, so maybe it's wrong. There are several versions of sketchup...one is for woodworking and one or more of the others (can't remember what they call them) are more aimed at construction. If you're using the woodworking version and they have it programmed to shrink your proportions under the assumption that you're using construction lumber to build furniture, then someone needs to contact the dorks at gargle and explain to them how things work in the world in which men live. In the same vein, real men don't use sketchup...they doodle on a napkin. Quote Link to comment Share on other sites More sharing options...
DaveT Posted June 16, 2014 Report Share Posted June 16, 2014 In old construction I've seen 2x beams that are a full 2" thick with the rough saw marks from the lumber mill. I had to go crawling through some loft spaces in old houses to put network cables in (I was the only one thin enough to fit). Some of the roof beams were still round except where they needed to join another, and as for straight - not on your Nelly! Very close resemblance to the hind leg of mans best friend. Quote Link to comment Share on other sites More sharing options...
Byrdie Posted June 24, 2014 Report Share Posted June 24, 2014 I've lived in two different houses recently, the last one was a farm house built in the teens, the current one is half a building that was built in the 50s and the other half a structure that was moved in, where the floor joists/beams are basically logs that were flattened on one side and only squared on the sides where they were larger than a certain dimension. Also at the farm house was a barn that was at least as old as the house and most of the supporting structure had only been squared as much as necessary. I made some revisions to the barn and new lumber had to be bought oversize and cut to match existing studs, etc. Quote Link to comment Share on other sites More sharing options...
Shane Jimerfield Posted June 24, 2014 Report Share Posted June 24, 2014 Kiki, those are the rough sawn dimensions, aka nominal. They get reduced from the nominal dimensions to the actual by the planner. It's my understanding that they cut construction lumber at the stated dimensions, i.e. 2x4, and then it shrinks in the kiln. That may or may not be correct. You would think a 2x12 would shrink more than a 2x4, so maybe it's wrong. There are several versions of sketchup...one is for woodworking and one or more of the others (can't remember what they call them) are more aimed at construction. If you're using the woodworking version and they have it programmed to shrink your proportions under the assumption that you're using construction lumber to build furniture, then someone needs to contact the dorks at gargle and explain to them how things work in the world in which men live. In the same vein, real men don't use sketchup...they doodle on a napkin. Sent from my KFTHWI using Tapatalk HD Quote Link to comment Share on other sites More sharing options...
Trip Posted June 24, 2014 Report Share Posted June 24, 2014 The standards-change from nominal to dimensional occurred in the mid '60s... The change in standards simply formalized what was already occurring in several parts of the country... It took several years for the change-over as existing lumber stocks were depleted. The change-over to nominal from fully-dressed nominal occurred much earlier... Maybe Shannen can chime-in on this one... Quote Link to comment Share on other sites More sharing options...
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