Blueprints?
- Thread starter kg18
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southernboys
Senior Member
Re: Blueprints?
depends on your prints you shoul have a scale if not on elec prints check architectiual
depends on your prints you shoul have a scale if not on elec prints check architectiual
tx2step
Senior Member
- Location
- North Texas, DFW area
Re: Blueprints?
Celtic is right -- there is no "standard" scale for residential or for commercial or industrial. The scale is whatever the architect or owner chooses to use, trying to make the drawing fit on a page and still be legible.
Look for a scale listed on the drawing, and then double check it to verify it. Sometimes the scale they show is wrong.
If there is no scale listed, look for a room or part of the building that is dimensioned (i.e. from this point to that point is 49'-8").
Use a 3 sided (triangular) architectural scale (ruler) and see which of the 6 scales match that dimension.
Check several places if there are that many dimensioned.
If you know the outside dimension of the building is 50' X 50' -- see what scale on the 3 sided ruler gives you the correct measurement.
Don't get an architectural scale (which reads in scales like 1/4"= 1'-0", 1/8"= 1'-0") mixed up with an engineering scale (also a 3 sided triangular ruler but has scales of 1"=10', 1"=20', 1"=30', etc. Engineering scales are usually used for site plans)
Also, watch out for reduced drawings . These drawings look just like the full size drawings but have been shrunk. Sometimes they are marked "reduced" and sometimes they aren't.
Half size drawings are fairly common in commercial work -- I don't know about residential. But if you bid from a reduced drawing, all of you scaled measurements (conduit, wire, etc.) will be off by the amount of the reduction (unless you compensate for the reduction -- i.e. 1/4"= 1'-0" becomes 1/8"= 1'-0").
I've seen jobs landed that way -- the contractor didn't catch his mistake until it was too late. It's a good way to be very low on a bid.
If you use a scaled ruler on a dimensioned part of the building (on several dimensioned parts if possible) to verify the scale, you can catch reduced drawings even if they aren't marked.
[ April 14, 2005, 02:20 AM: Message edited by: tx2step ]
Celtic is right -- there is no "standard" scale for residential or for commercial or industrial. The scale is whatever the architect or owner chooses to use, trying to make the drawing fit on a page and still be legible.
Look for a scale listed on the drawing, and then double check it to verify it. Sometimes the scale they show is wrong.
If there is no scale listed, look for a room or part of the building that is dimensioned (i.e. from this point to that point is 49'-8").
Use a 3 sided (triangular) architectural scale (ruler) and see which of the 6 scales match that dimension.
Check several places if there are that many dimensioned.
If you know the outside dimension of the building is 50' X 50' -- see what scale on the 3 sided ruler gives you the correct measurement.
Don't get an architectural scale (which reads in scales like 1/4"= 1'-0", 1/8"= 1'-0") mixed up with an engineering scale (also a 3 sided triangular ruler but has scales of 1"=10', 1"=20', 1"=30', etc. Engineering scales are usually used for site plans)
Also, watch out for reduced drawings . These drawings look just like the full size drawings but have been shrunk. Sometimes they are marked "reduced" and sometimes they aren't.
Half size drawings are fairly common in commercial work -- I don't know about residential. But if you bid from a reduced drawing, all of you scaled measurements (conduit, wire, etc.) will be off by the amount of the reduction (unless you compensate for the reduction -- i.e. 1/4"= 1'-0" becomes 1/8"= 1'-0").
I've seen jobs landed that way -- the contractor didn't catch his mistake until it was too late. It's a good way to be very low on a bid.
If you use a scaled ruler on a dimensioned part of the building (on several dimensioned parts if possible) to verify the scale, you can catch reduced drawings even if they aren't marked.
[ April 14, 2005, 02:20 AM: Message edited by: tx2step ]
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: Blueprints?
Usually on residential it is 1/4 inch = 1 foot.Have yet to be handed a full set of prints that did not mark the scale.They try to get the thing on one page so some very large buildings must change the scale.First thing you must do before anything else is find that scale.Look for an easy measurement on it and check it,like 4foot 0 inches ,if its 1 inch then you know,if not find out why.
Usually on residential it is 1/4 inch = 1 foot.Have yet to be handed a full set of prints that did not mark the scale.They try to get the thing on one page so some very large buildings must change the scale.First thing you must do before anything else is find that scale.Look for an easy measurement on it and check it,like 4foot 0 inches ,if its 1 inch then you know,if not find out why.
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: Blueprints?
You also need to be careful to distinguish what I might call ?true half size? from a sheet that looks like it?s about half the size of a full sized sheet. For the sake of making easy copies, a drawing might be ?printed? onto a standard computer printer at 11x17, giving you what only looks about like half size, instead of being ?plotted? on a drafting plotter, giving you a true half size.
I like to be kind to my audience. So I insist that all my floor plans have not only a scale declared on the sheet, but also have a ?graphic scale.? That is an image of a ?ruler? that shows what distance on the page equates to what distance on the final, constructed building. If the drawing is reduced to any other size, the graphic scale is reduced along with it. You can always get an accurate estimate of the distances.
You also need to be careful to distinguish what I might call ?true half size? from a sheet that looks like it?s about half the size of a full sized sheet. For the sake of making easy copies, a drawing might be ?printed? onto a standard computer printer at 11x17, giving you what only looks about like half size, instead of being ?plotted? on a drafting plotter, giving you a true half size.
I like to be kind to my audience. So I insist that all my floor plans have not only a scale declared on the sheet, but also have a ?graphic scale.? That is an image of a ?ruler? that shows what distance on the page equates to what distance on the final, constructed building. If the drawing is reduced to any other size, the graphic scale is reduced along with it. You can always get an accurate estimate of the distances.
sandsnow
Senior Member
- Location
- Southern California
Re: Blueprints?
Why do you want to measure on the drawing?? as Charlie said scaling something off the drawing is for an ESTIMATION only.
Some things I've learned:
Written dimensions take priority
Never get locations or heights from an E sheet. Use the A sheets
For cabinets or other elevations, go to the a sheets or details.
Better yet, get the cabinet drawings or submittals from the superintendent.
When in doubt, write an RFI or get the superintendent to verify location in writing. A box half in and half out the tile looks stupid and costs your company money for your mistake.
Why do you want to measure on the drawing?? as Charlie said scaling something off the drawing is for an ESTIMATION only.
Some things I've learned:
Written dimensions take priority
Never get locations or heights from an E sheet. Use the A sheets
For cabinets or other elevations, go to the a sheets or details.
Better yet, get the cabinet drawings or submittals from the superintendent.
When in doubt, write an RFI or get the superintendent to verify location in writing. A box half in and half out the tile looks stupid and costs your company money for your mistake.
sandsnow
Senior Member
- Location
- Southern California
Re: Blueprints?
What's even more hokey is when the bottom of the box is just above the tile and the electrician has to trim the bottom of the plate off to fit above the tile. Now that could be considered a violation. 110.3(B)
If the top half of the box is above the tile and the bottom half in the tile, a box extension (cheater ring or arc shield) can be used to make it legal, but not pretty. The box or P-ring would be flush or set back from the drywall.Originally posted by celtic:
Isn't that a code violation?
What's even more hokey is when the bottom of the box is just above the tile and the electrician has to trim the bottom of the plate off to fit above the tile. Now that could be considered a violation. 110.3(B)
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Blueprints?
We had one the other day that the tile man got a little creative. After the house was trimmed out the home owner decided he wanted tile around the kitchen, The tile man cut plug and switch plates out of full pieces of tile that looked just like the rest And they look pretty darn good. But the inspector wanted to know if they were listed
We had one the other day that the tile man got a little creative. After the house was trimmed out the home owner decided he wanted tile around the kitchen, The tile man cut plug and switch plates out of full pieces of tile that looked just like the rest And they look pretty darn good. But the inspector wanted to know if they were listed
sandsnow
Senior Member
- Location
- Southern California
Re: Blueprints?
I can relate to that. I will spend hours trying to get something just so.Originally posted by hurk27:
We had one the other day that the tile man got a little creative. After the house was trimmed out the home owner decided he wanted tile around the kitchen, The tile man cut plug and switch plates out of full pieces of tile that looked just like the rest And they look pretty darn good. But the inspector wanted to know if they were listed
Re: Blueprints?
Lesson Learned.......
The electrical drawing most of the time only show what electrical requirement are needed. But when it comes to actually rough-in for it, you have to reference the elevational drawings for exact placement. If they would have view the elevational plans for the bathroom wall this mistake could have been avoided.
Boils down to experience!
Lesson Learned.......
The electrical drawing most of the time only show what electrical requirement are needed. But when it comes to actually rough-in for it, you have to reference the elevational drawings for exact placement. If they would have view the elevational plans for the bathroom wall this mistake could have been avoided.
Boils down to experience!
the High Wirey
New member
Re: Blueprints?
Steve66's answer is good.
Steve66's answer is good.
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