# Finding jousts and rafters



## besc (May 16, 2010)

I live where we install solar panels on old houses that were just thrown up in there day. The joists and studs distances vary wildly. You practically have to drill a search whole on some of these houses. Any ideas on how to accurately locate these items. I'll buy a stud finder that actually works if need be. Thanks. Mike.


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## MechanicalDVR (Dec 29, 2007)

I'd go for a 'deep scan' stud finder.


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## besc (May 16, 2010)

Could u give me more info please.


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## macmikeman (Jan 23, 2007)

Get inside the attic and carefully measure and map out the rafters. Or send in a carpenter to add blocking between them and use that instead of the rafter itself. 

1/2 of the pv companies that operated on Oahu during the boom are now gone and homeowners are furious at the leaking roof problems that have shown up.


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## joebanana (Dec 21, 2010)

The UBC states studs and rafters be on 16" centers.
That way 8' long sections of sheeting end up on a stud. Your tape measure has special marks on it every 16" to make it easier.


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## Majewski (Jan 8, 2016)

You gotta do a lot of trial and error since every structure can vary wildly but like Mike says, gotta get in there!


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## macmikeman (Jan 23, 2007)

joebanana said:


> The UBC states studs and rafters be on 16" centers.
> That way 8' long sections of sheeting end up on a stud. Your tape measure has special marks on it every 16" to make it easier.


Usually rafter tails spill out over the sides of the dwelling resulting in overhangs. Measuring these on both sides will usually get you good results. When its a neighborhood where all the houses look pretty much alike and you realize its a trac home development, you would be surprised at how many times the measurement doesn't fall on 16'' (usually more like 24'' actually). The kids they hire often get the x on the wrong side of the line, so one side is fine but by the time it gets to the other side of the house it is off 1-1/2'' from correct. 
Trac housing is rubbish.


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## splatz (May 23, 2015)

joebanana said:


> The UBC states studs and rafters be on 16" centers.
> That way 8' long sections of sheeting end up on a stud. Your tape measure has special marks on it every 16" to make it easier.


I think there are provisions for different spacings with different types of framing, I saw homes being built with 4x4 studs at 2' OC a couple years ago. 

The older homes, even very well built buildings, they did not necessarily use a 16" OC spacing.


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## macmikeman (Jan 23, 2007)

splatz said:


> I think there are provisions for different spacings with different types of framing, I saw homes being built with 4x4 studs at 2' OC a couple years ago.
> 
> The older homes, even very well built buildings, they did not necessarily use a 16" OC spacing.


Must be a snow load thing, but I never see truss on 16's. Always 24.


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## telsa (May 22, 2015)

Send a trooper into the target attic with NIB magnets// or target iron.

Magnetic fields will shoot right through the roof.

You should be ashamed that such an obvious play didn't pop right into your head.

BTW, the magnets// iron can be positioned from an extendible pole. 

LSD's Zip-It comes to mind.

BTW, I hate roof top solar.

As MacMike relates, you're SURE to ruin the roof.


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## telsa (May 22, 2015)

macmikeman said:


> Usually rafter tails spill out over the sides of the dwelling resulting in overhangs. Measuring these on both sides will usually get you good results. When its a neighborhood where all the houses look pretty much alike and you realize its a trac home development, you would be surprised at how many times the measurement doesn't fall on 16'' (usually more like 24'' actually).  The kids they hire often get the x on the wrong side of the line, so one side is fine but by the time it gets to the other side of the house it is off 1-1/2'' from correct.
> Trac housing is rubbish.


*BINGO.* :yes:


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## joebanana (Dec 21, 2010)

macmikeman said:


> Usually rafter tails spill out over the sides of the dwelling resulting in overhangs. Measuring these on both sides will usually get you good results. When its a neighborhood where all the houses look pretty much alike and you realize its a trac home development, you would be surprised at how many times the measurement doesn't fall on 16'' (usually more like 24'' actually).  The kids they hire often get the x on the wrong side of the line, so one side is fine but by the time it gets to the other side of the house it is off 1-1/2'' from correct.
> Trac housing is rubbish.


What kind of houses do you work on? I'm talking about houses built by professional licensed carpenter's, not Labor Ready/imported grunts. 
I'll bet the drywallers, and roofers just love doing the type of stuff you're talking about. All the tract homes I've done in Cali. are 16" centers. In Brentwood, and Beverly Hills, I have seen rough sawn 2" x 4"s that are actually 2 x 4, and on 16" centers. Those homes have rigid conduit in the walls. But...there are times when you have to tilt your head to get the proper perspective. :blink:


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## macmikeman (Jan 23, 2007)

joebanana said:


> What kind of houses do you work on? I'm talking about houses built by professional licensed carpenter's, not Labor Ready/imported grunts.
> I'll bet the drywallers, and roofers just love doing the type of stuff you're talking about. All the tract homes I've done in Cali. are 16" centers. In Brentwood, and Beverly Hills, I have seen rough sawn 2" x 4"s that are actually 2 x 4, and on 16" centers. Those homes have rigid conduit in the walls. But...there are times when you have to tilt your head to get the proper perspective. :blink:


Added note for effect. The trac housing jobs are staffed almost always by union companies 100%. Union Carpenters. 

Now, I wish I had that jew bagel breakfast Hax was telling me about.


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## frenchelectrican (Mar 15, 2007)

Most house I useally run into are set for 16 or 24 OC ( or 40 or 60 CM ) depending on location and style of roof and larger roofs intend to be more on 16 which it kinda norm unless you ran into big arse 2X8 or larger rafters that is kinda tossed up.


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## joebanana (Dec 21, 2010)

macmikeman said:


> Added note for effect. The trac housing jobs are staffed almost always by union companies 100%. Union Carpenters.
> 
> Now, I wish I had that jew bagel breakfast Hax was telling me about.


Tract housing is NEVER staffed with union anything. The builders can't afford union rates, and still be competitive. Commercial, yes, residential, nope. At least not here. Residential only pay's $10/hr. or a buck a hole for trim, tops.


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## telsa (May 22, 2015)

joebanana said:


> Tract housing is NEVER staffed with union anything. The builders can't afford union rates, and still be competitive. Commercial, yes, residential, nope. At least not here. Residential only pay's $10/hr. or a buck a hole for trim, tops.


Joe, tract builders can afford natives.

When ICE shows up, the 'talent' runs for the hills. That's not an exaggeration.

Even with that brutal wage suppression, home prices are in orbit, hereabouts.


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## Switched (Dec 23, 2012)

joebanana said:


> Tract housing is NEVER staffed with union anything. The builders can't afford union rates, and still be competitive. Commercial, yes, residential, nope. At least not here. Residential only pay's $10/hr. or a buck a hole for trim, tops.


I know plenty of EC's doing NC residential paying $40-$45 an hour for residential Jmen, but those are typically custom and spec. homes. I can only guess as to tracts.

From my experience, resi. framing runs in the 16-24" range, with some of the older single wall framed houses being 48" on center.


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## joebanana (Dec 21, 2010)

Switched said:


> I know plenty of EC's doing NC residential paying $40-$45 an hour for residential Jmen, but those are typically custom and spec. homes. I can only guess as to tracts.
> Where? Not in Cali. You'll never find a $40/hr. roper. Custom home builders use a Beverly Hills contractor, or someone with a new shiny truck, and they aint union. (I used to do a lot of work in the area).
> 
> From my experience, resi. framing runs in the 16-24" range, with some of the older single wall framed houses being 48" on center.


 I have never seen 4' on center framing, anywhere, but I'll take your word for it.


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## backstay (Feb 3, 2011)

Just saying:whistling2:


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## Switched (Dec 23, 2012)

joebanana said:


> I have never seen 4' on center framing, anywhere, but I'll take your word for it.


There was a style of framing and building back in the day.... They would frame out the house with minimal timber, typically 48" on center. Once they framed it up they would apply the interior wall, which was just the exterior wall. It consisted of 1x12's vertically installed. 

I can say these houses are scattered throughout the Bay Area and Monterey Bay as I have worked on a number of them.

The only type of framing I have never run into is Balloon Framing, I know it was wildly popular on the East Coast, but it didn't seem to make its way to the West.

Here is a good synopsis... https://en.wikipedia.org/wiki/American_historic_carpentry#Vertical_Plank_wall


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## MechanicalDVR (Dec 29, 2007)

joebanana said:


> The UBC states studs and rafters be on 16" centers.
> That way 8' long sections of sheeting end up on a stud. Your tape measure has special marks on it every 16" to make it easier.


There are millions of houses built before any UBCexisted.

UBC really doesn't apply to government build housing projects or engineered modular construction.

Rafters can be on 12", 16", or even 24" centers depending on roof decking.

Truss framing or prefab type framing is normally 24" centers.

If you don't want to or can't get into the attic, deep scan stud finder is best in combination with hammer tapping.


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## telsa (May 22, 2015)

joebanana said:


> I have never seen 4' on center framing, anywhere, but I'll take your word for it.


My sister's home uses 48" on center framing for its floor joists... ! 

Not kidding. :thumbsup:

The droop after forty-years was absurd. 

I had to remediate... plenty.


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## frenchelectrican (Mar 15, 2007)

Switched said:


> There was a style of framing and building back in the day.... They would frame out the house with minimal timber, typically 48" on center. Once they framed it up they would apply the interior wall, which was just the exterior wall. It consisted of 1x12's vertically installed.
> 
> I can say these houses are scattered throughout the Bay Area and Monterey Bay as I have worked on a number of them.
> 
> ...


I have ran into alot of balloon frames home even commercal buildings before .,, they are pretty easy to snake in the cables but the only drawbacks with most of the balloon frames is fireblocks that you will hit them about half way up it dont have specfic height but expect to hit them.


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## splatz (May 23, 2015)

You might not believe this but one of my industrial customers has 10' spacing between beams and NO floor joists. It's a turn of the century (20th) building. The beams and columns are made from 1'x1'x10' wood with steel brackets joining them. It's like a tinkertoy frame. 

The floors are 1x8 yellow pine, one layer going north-south, one layer going east-west, and one layer diagonal. 

The floors do have some spring and it's noisy the floor below if someone rolls a cart the floor above. 

There are joists or an extra beam here and there where there is or was something heavy but they are few and far between.


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## joebanana (Dec 21, 2010)

MechanicalDVR said:


> There are millions of houses built before any UBCexisted.
> 
> UBC really doesn't apply to government build housing projects or engineered modular construction.
> 
> ...


Apparently it's not the UBC any more, now it's the IBC.
I was just generalizing. The majority of modern stick frame residential dwellings are 16" o/c.
There are exceptions to every rule, otherwise, we wouldn't need them.
I was just tossing the dude a bone, since he sounded "unsure" of how to apply his craftsmanship to the project at hand.
Geeezee :001_huh:


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## joebanana (Dec 21, 2010)

telsa said:


> My sister's home uses 48" on center framing for its floor joists... !
> 
> Not kidding. :thumbsup:
> 
> ...


That's why they don't build them like that anymore. Is it a custom home? Imagine what a wall built on 4' centers would look like after 40 years. And floors don't have to handle snow load either. Maybe that's why they went to 16" centers, besides it dividing into 8' evenly.


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## wildleg (Apr 12, 2009)

besc said:


> I live where we install solar panels on old houses that were just thrown up in there day. The jousts and studs distances vary wildly. You practically have to drill a search whole on some of these houses. Any ideas on how to accurately locate these items. I'll buy a stud finder that actually works if need be. Thanks. Mike.


www.knightsofmiddleengland.com/jousting-displays/


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## joebanana (Dec 21, 2010)

wildleg said:


> www.knightsofmiddleengland.com/jousting-displays/


WTF? :blink:


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## MechanicalDVR (Dec 29, 2007)

joebanana said:


> Apparently it's not the UBC any more, now it's the IBC.
> I was just generalizing. The majority of modern stick frame residential dwellings are 16" o/c.
> There are exceptions to every rule, otherwise, we wouldn't need them.
> I was just tossing the dude a bone, since he sounded "unsure" of how to apply his craftsmanship to the project at hand.
> Geeezee :001_huh:


I've been involved in many different projects on houses over the years and have found the variances in framing centers very frustrating to say the least.

Wasn't trying to bust balls in the least.


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## A Little Short (Nov 11, 2010)

joebanana said:


> Apparently it's not the UBC any more, now it's the IBC.
> I was just generalizing. The majority of modern stick frame residential dwellings are 16" o/c.
> There are exceptions to every rule, otherwise, we wouldn't need them.
> I was just tossing the dude a bone, since he sounded "unsure" of how to apply his craftsmanship to the project at hand.
> Geeezee :001_huh:


The OP didn't say he didn't know the "standard", read what he said.
He said they are old houses vary from house to house.



besc said:


> I live where we install solar panels on old houses that were just thrown up in there day. *The joists and studs distances vary wildly.* You practically have to drill a search whole on some of these houses. Any ideas on how to accurately locate these items. I'll buy a stud finder that actually works if need be. Thanks. Mike.


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## joebanana (Dec 21, 2010)

MechanicalDVR said:


> I've been involved in many different projects on houses over the years and have found the variances in framing centers very frustrating to say the least.
> 
> Wasn't trying to bust balls in the least.


Oh yeah, I've had my share, but I have found ~16" o/c gets me in the ball park most of the time. I've got a super small drill bit, around a 1/32" that I use for probing drywall. I'll admit, I haven't done any residential for at least 20 years, but, I don't think it's changed that much. The thing that's changed the most is the NEC. My first code book was the 1975 edition, it was 5"x 7.5" x 1", and easy to understand.


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## joebanana (Dec 21, 2010)

A Little Short said:


> The OP didn't say he didn't know the "standard", read what he said.
> He said they are old houses vary from house to house.


That's what I gave him, was the "standard". I'm not familiar with "framing joists and studs with distances that Vary Wildly". 
I've always had pretty good luck with a tape measure, a chalk line, and the 16" rule. Once you find one the rest aren't that hard. Unless they "vary wildly", then I can't help. Yeah, I know, it's rare to find a tradesman that can read a tape measure these days but, it beats poking a bunch of holes in someones roof. And a stud finder on shake shingle, or Spanish tile roof, is a hit or miss venture, on a good day.


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## splatz (May 23, 2015)

Thinking about this some more - I see a lot of old framing methods around here. I have also read some of the old Audel's books and others about construction methods from 50-100 years ago. 

I don't remember how the tables were laid out back then but I wonder. Today's framing is almost all platform framing. The lumber is short, but you can get anything from 2x4's to 2x12's. There are lookup tables based on a few standard spacings, telling you how wide your rafters have to be. 

I don't remember seeing any huge lumber used for rafters in old houses, and certainly no trusses, usually you just see the old dimensional 2x4's. The lookup tables might have worked the other way around, there were only a couple sizes used, so you looked up your spacing based on the span and load. I see all kinds of odd rafter spacings around here, in houses from around the turn of the century. You'll see 19", 23", all odd stuff. 

Another thing with balloon framing. With this method it was no big deal to alter your stud spacing a bit to position doors and windows where you wanted them. (You can do all kinds of crazy things with balloon framing, it's no big deal to have the second story floors at two different levels.) The rafters might then be stacked on the studs, that is, they'd follow the stud spacing. 

Whatever the case - working from the attic is going to give your best results. Check the spacing up there, if it's regular then you're set once you find the first rafter. 

If the spacing is irregular it is going to be tough - best bet might be to tack up a piece of joint tape across the rafters, mark the rafter locations, and use that as a pattern to locate them on top.


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## sbrn33 (Mar 15, 2007)

joebanana said:


> The UBC states studs and rafters be on 16" centers.
> That way 8' long sections of sheeting end up on a stud. Your tape measure has special marks on it every 16" to make it easier.


Don't get all mad at us when you throw out something like this that is not even close to being right. 
16" is a standard but not a code in any way shape or form.


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## MechanicalDVR (Dec 29, 2007)

splatz said:


> Thinking about this some more - I see a lot of old framing methods around here. I have also read some of the old Audel's books and others about construction methods from 50-100 years ago.
> 
> I don't remember how the tables were laid out back then but I wonder. Today's framing is almost all platform framing. The lumber is short, but you can get anything from 2x4's to 2x12's. There are lookup tables based on a few standard spacings, telling you how wide your rafters have to be.
> 
> ...



I could be wrong but of all the houses I have ever seen framing standardization doesn't really seemed to have occurred until the 1940's when sub divisions and groups of houses were built.

Also kit homes like the ones Sears and Roebucks sold that had blueprints and cut sheets helped this all along.

When houses were framed without any regard to insulation or plywood sizing things were vastly different as to after those items were considered.

Varying lengths of tongue and groove or shiplap sheathing boards and roof decking made framing member spacing irrelevant and unimportant.


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## splatz (May 23, 2015)

MechanicalDVR said:


> I could be wrong but of all the houses I have ever seen framing standardization doesn't really seemed to have occurred until the 1940's when sub divisions and groups of houses were built.
> 
> Also kit homes like the ones Sears and Roebucks sold that had blueprints and cut sheets helped this all along.
> 
> ...


That's a real good point about the Craftsman houses and other kit houses. This was literally a do it yourself house out of a catalog, hard to imagine this now! I imagine a person building their own house from a kit might get the roof rafters a little irregular and say "close enough."


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## MechanicalDVR (Dec 29, 2007)

splatz said:


> That's a real good point about the Craftsman houses and other kit houses. This was literally a do it yourself house out of a catalog, hard to imagine this now! I imagine a person building their own house from a kit might get the roof rafters a little irregular and say "close enough."


Of all the kit homes I've seen they all seemed to have had very good 'instructions' and people followed them.

I can't recall the name brand of them but I've also seen homes from the early 50s that had the oldest form of residential trusses I've ever seen. 

They were between a wooden ribbon truss and a typical ladder truss, they were basically constructed of 2"x3"s and placed @ 24" on center with 3/8" plywood sheathing and 1/2" plyscore roof decking.


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## joebanana (Dec 21, 2010)

sbrn33 said:


> Don't get all mad at us when you throw out something like this that is not even close to being right.
> 16" is a standard but not a code in any way shape or form.


When did I say it was a code? What do YOU think the "C", in UBC stands for? "not even close to being right"? I'm closer than you are.


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## emtnut (Mar 1, 2015)

I've done work in a lot of old 'turn of the century' homes here. Most are balloon framed on 36" centers.

Where the door is, they'd move the 36" center to 40, 42 46 ... whatever they needed, and continued on at 36" from there.

The trusses are on the same 36" centers as well.
This is all rough saw mill 2" X 4". On either side were 1" X whatever inch barnboards on either side. Then they had 3/4" tongue and grove on top of that on both sides. Built like a brick sh!t house :thumbsup:

Walls are 9 1/2" thick. Most of these homes either had no insulation, or saw dust in the 2X4 opening :blink:


Good ol days when wood and nails must have been free :laughing:


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## wildleg (Apr 12, 2009)




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## splatz (May 23, 2015)

wildleg said:


>


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