# Attic Framing Confusion...



## Bob Mariani (Dec 1, 2008)

Just remove them. The carpenter just had extra wood left over. IGNORE THE FIRST STATEMENT.... Sounds like you have trusses. None of these can be removed or even cut. This attic is not designed to carry a live load. Attics are not built to be rooms without structural changes. What are the ceiling joist size, spacing and span? What are the header sizes over windows below this area? What roof type do you have?


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## MI-Roger (Aug 8, 2009)

*Call an architect.......*

A structural engineer could answer the roof framing question too, but converting an attic space into livable area may involve other itmes that an architect can best answer: means of egress, minimum allowable fenestration for natural light, etc.

I have seen photos of attics like you have described. Although simple removal may not be allowable, framing knee walls and a flat ceiling into the space between the rafters may provide the same reinforcement the angular braces are currently providing.

You will need plans to obtain the various building permits. May as well have an architect create them. The initial look-see may be free if the roof framing is indeed trusses which cannot be modified.


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## Gary in WA (Mar 11, 2009)

Ridge beam and main beam ----- sounds like stick framed roof. Does the ridge board run continuous to tie each rafter?

Be safe, Gary


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## vsheetz (Sep 28, 2008)

Got pictures?


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## Paulie (Nov 26, 2009)

Pictures would be great but there are a ton of issues with converting a attic space. Most of which a structural engineer would be needed to answer and sign off on before a permit would be issued. Some of which are #1.floor deflection and spanning. What is it going to be used for? A bedroom has a different load/span than just living space. #2.Egress. #3. Stairway and landings, it's a trouble spot with attic's. #4. Headroom, there are specific codes that need to be met for allowable ceiling height. #5. Insulation, if you do insulate to the new energy codes you will probably have to build down the roof rafters or if you get grandfathered in, one normally has to create pass by's to let the roof "breathe" to a ridge vent. #6. If you plan to hang drywall the extra load of the drywall has to be calculated in roof load. I guess I've gone on enough but you get the picture. :blink:


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## Yoyizit (Jul 11, 2008)

http://www.diydoctor.org.uk/project_images/roof_trusses/Trusses 1.jpg
All the truss members are subjected to bending or compressive forces, if it is designed correctly.


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## Jamison1114 (Dec 8, 2009)

These do not tie in each rafter, and some of the vertical 2x4's aren't even supporting wait. Some 2x4's are dangling from there nails on the Ridge Beam, not even supporting wait...really just dangling. Must be some sort of attic wind chime? lol. 

yoyizit... the trusses are shaped like the "Home Girder" style...minus the smaller vertical studs.

I'm wanting to use this as a storage area, maybe even an extra room if possible. If I were placing a room in the attic with about 8' of head room, this attic would be 11' x 40'. 

Here's a rough drawing I made...


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## Clutchcargo (Mar 31, 2007)

What is the lumber size of the rafter. It could be someone's attempt to stop a sagging ridge and rafters.
If the rafters are 2x4 then most likely it's a engineered truss.


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## Jamison1114 (Dec 8, 2009)

I'll climb up into my attic and find out the rafter size tonight. There's not a lot of light, but I'll also try to take a picture as well. I'm sure the rafters aren't 2x4's.


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## Daniel Holzman (Mar 10, 2009)

You can tell if it is an engineered truss by looking at the connections between the 2x4 elements. If it is engineered, you will find stitch plates with gang nails connecting the elements, if you find ordinary nails it is a stick built truss.

Regardless, you stated that you may want to use the space as a room, or possibly for storage. If only for storage, you may be able to use it as is, however if you want it to be habitable, see previous posts, you are going to need professional assistance of the type not generally available over the internet in a DIY forum, as previously noted in several posts. In any case, removal of the diagonal elements without a careful, thorough, professional analysis would be very bad idea, likely to lead to great grief and consternation.


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## Jamison1114 (Dec 8, 2009)

There are no stitch plates. This is a poorly done stick built construction. Like I said...most of these are dangling. You're probably right. I need to hire someone to come out. I'm afraid of what the price would be just to have it evaluated, let alone have someone redraw some plans. Any ideas as to what to expect on pricing?


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## Michael Thomas (Jan 27, 2008)

Around here - Chicago - the SE I recommend would typically charge around $350-400 for the site visit, and $500+ for the stamped plans if it's a simple fix.


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## ClemS (Dec 13, 2009)

they typically blocked up this way on long, undersized rafters. do not remove anything and have someone come out and look at it to evaluate.


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## pyper (Jul 1, 2009)

In my house the rafters are undersized. They're true dimension 2x4s with a 15' span (about 20 feet long). Those 2x4s that go up on an angle serve to cut the span. They didn't put one on every rafter, but there are various pieces nailed across the rafters that seem to effectively distribute the load. Well, that, and the tongue and groove decking.

Measure the span of your rafter, and look it up in a span chart. If your rafters are undersized for the span, then the 2x4's are there to prevent sag.


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## ClemS (Dec 13, 2009)

pyper said:


> In my house the rafters are undersized. They're true dimension 2x4s with a 15' span (about 20 feet long). Those 2x4s that go up on an angle serve to cut the span. They didn't put one on every rafter, but there are various pieces nailed across the rafters that seem to effectively distribute the load. Well, that, and the tongue and groove decking.
> 
> Measure the span of your rafter, and look it up in a span chart. If your rafters are undersized for the span, then the 2x4's are there to prevent sag.



being that your ceiling joists are also under-sized, the 2x4's aren't preventing much of anything. it's just the way these things were built, before building codes and span charts. oddly enough, some framers will still post their long rafters/hip/valleys down to practically nothing.

sometimes it's even called out on the drawings


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## pyper (Jul 1, 2009)

ClemS said:


> being that your ceiling joists are also under-sized, the 2x4's aren't preventing much of anything. it's just the way these things were built, before building codes and span charts.


Not true -- the 2x4's come down on a load bearing wall (where the joists are tied together).

If they did come down on under-sized joists mid-span they would be pretty pointless.


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## ClemS (Dec 13, 2009)

pyper said:


> Not true -- the 2x4's come down on a load bearing wall (where the joists are tied together).
> 
> If they did come down on under-sized joists mid-span they would be pretty pointless.


you lucked out on that one :thumbsup: most of the time these struts just land in the middle of nowhere. is there a center girder in your house?


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## pyper (Jul 1, 2009)

ClemS said:


> you lucked out on that one :thumbsup: most of the time these struts just land in the middle of nowhere. is there a center girder in your house?


My house is build "beam on pier." 

There's a 12x14 grid of brick piers with 6x8 oak beams connecting them. The center wall is on a beam, just like the end beams. I calculated that each beam can carry about 10,000 lbs.


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## ClemS (Dec 13, 2009)

pyper said:


> My house is build "beam on pier."
> 
> There's a 12x14 grid of brick piers with 6x8 oak beams connecting them. The center wall is on a beam, just like the end beams. I calculated that each beam can carry about 10,000 lbs.


sounds like a solid SOB :thumbsup:


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## Gary in WA (Mar 11, 2009)

Pyper, you have purlins and struts, to shorten the span of the rafter to use smaller material: second page, middle picture: http://books.google.com/books?id=1f...sult&resnum=1#v=onepage&q=collar ties&f=false

The O.P. drew a horizontal member tying and supporting the struts, which sounds like there is no bearing wall directly below the ridge board. I agree, have a Structural Engineer look at it for plan of attack. 
Be safe, Gary


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## pyper (Jul 1, 2009)

GBR in WA said:


> Pyper, you have purlins and struts, to shorten the span of the rafter to use smaller material: second page, middle picture: http://books.google.com/books?id=1f...sult&resnum=1#v=onepage&q=collar ties&f=false
> 
> The O.P. drew a horizontal member tying and supporting the struts, which sounds like there is no bearing wall directly below the ridge board. I agree, have a Structural Engineer look at it for plan of attack.
> Be safe, Gary



The top of a bearing wall _is_ a horizontal member. I wouldn't want to read too much into a rough sketch.

Not that it matters to the OP, but I don't have purlins -- just struts and collar ties. There are assorted horizontal members tied on diagonals across the bottoms of the joists. I really think it's the roof decking that distributes the load.

Regardless of what's going on, the only rule we had when we did the recent work was "no cutting into the stuff in the attic." :thumbsup:

I'm definitely not endorsing the construction method used in my house, but it seems to have held up. I had also considered going in and beefing it up with actual purlins and more struts, but then I decided not to, on the basis that there didn't seem to be any problem and I definitely don't want to create one.


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## Gary in WA (Mar 11, 2009)

Pyper, I, too, have found many older roofs systems with struts tied to purlins, struts tied to rafters and 6’ non-continuous nailers going perpendicular to the rafters. As you mentioned in your post: “various pieces nailed across the rafters that seem to effectively distribute the load.” Sometimes these nailers will have two struts (each end), and sometimes, only one for a 6’ long nailer. I wonder if these were used to support the installer as he was up there, and later, after sheathing, removed the nailer that tied them (the shorter nailers together for the proper layout) together. Interestingly, I find mostly 12’ long 1x6 or 1x8 boards on roofs, maybe to make it easier for the carpenter and his apprentice to install them without moving much. Yet they had access to 1st growth lumber in long lengths, like rafters. Perhaps I misunderstood you; I apologize if I offended you. 
A lot of the time there is not a bearing wall close below (2-4’), so the struts land on a strongback or single board on edge. This is what I understood the drawing to be. A picture is worth…….
Be safe, Gary


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## pyper (Jul 1, 2009)

Perhaps I misunderstood you; I apologize if I offended you. 


[/QUOTE]

No offense taken Gary. I think the best we can say is in the old days each carpenter probably had his own ideas about how to frame a building, and some of them were better than others. 

It would be great if we had a photo instead of a sketch.

In my house the "assorted nailers" seem to be diagonal braces that keep the rafters from racking. They're mainly 2x2, and pretty long. They go at any odd angle (probably depending on the length at hand).

I know that the wood used to frame my house is a lot stronger than modern wood -- some of the studs are so hard a screw will break off if you don't drill a pilot hole.


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