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What is this called?


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David,

What do you mean by "this"? Is it the vertical or horizontal member, since I assume you don't mean the rafter.

I would call the one running at 90 degrees to the rafters a "purlin", which needs to have the vertical ones "kicked off" to a bearing wall or some such. Then I could call the assembly a "braced purlin".

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Originally posted by Focal Point

I ran into this yesterday, I was not sure what the technical name for it is, so I called a framer buddy of mine. He said it's called a "stiffback"

Is that correct? is their a different name for it?

The proper term is "purlin."

- Jim Katen, Oregon

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In this case you could call it a purloined purlin. Or a purlin that was used to purloin the homeowner. In any case it is not a stiffback, but is being used as one because it is fastened on it's short side and not secured at the ends to a bearing point.

I'll bet that really clears things up for you!

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Hi,

Tom and I must be about the same age. Coming up, I was taught that a purlin was a member attached perpendicular to studs on the outside of the framing structure to which board-on-batten, batten-on-board, diagonal, drop, V-groove, T & G, or panel siding was attached. When used in roofs, they were on the outside of the rafters or trusses and were used to support metal roofing. On timber-frame structures the same thing.

In this case, it looks like the idea was to try and distribute the load between rafters, sort of a like a strongback does on a ceiling, but it doesn't look like it would be very effective for that. I see those a lot around here in older homes, but they are usually propped with struts that bear on top of wall plates below.

David,

If you pass your cursor over "resources" on the menu bar above it will produce a drop-down menu. Choose "Downloads" and then scroll down to FM 5-426, the Army basic carpentry manual. It was written by old-time carpenters and is a great resource. Look to the roofing section - page 7-11 - for an old time definition of purlin. It's over 250 pages though, so you'll need to have a pretty fast printer and lots of paper and toner if you want to print it out. Of course, you could always save it to your hard-drive and not waste the paper.

ONE TEAM - ONE FIGHT!!!

Mike

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Hi,

Yeah, it's sistered, so isn't the one directly behind it. That's common as fleas on an old mongrel around here in most of these old homes with the 25ft. long 2 by 4 rafters that are sagging like Aunt Millie's you know whats.

ONE TEAM - ONE FIGHT!!!

Mike

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Yes, they sistered about 10 of the rafters. Although you cannot see it the Purlin or stiffback whichever you prefer. is an L shape My framer buddy said since it's a L shape it's a Stiffback. Regardless of the name it’s basically worthless. It looks like monkeys scabbed this thing together and is not supported in any way.

Mike I downloaded that file you were telling me about a couple of weeks ago. I just haven’t had the time to poke my way thru it yet.

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...I was taught that a purlin was a member attached perpendicular to studs on the outside of the framing structure to which board-on-batten...

Up until the end of the first quarter of the 20th century, purlins referred to large structural members that are perpindicular to roof rafters. They can be below the rafters, like in most 18th century homes built by German settlers. They can be the beams that connect the large timber rafters that are common in early timber framed New England homes.

In the last 80 years, we Americans have corrupted the word to mean the boards installed across the top of the rafters for nailing shingles, slates or metal panels.

"Battenning" or "Battens" was the original term for those spaced boards.

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Slight thread drift......

We know what purlins are, but has anyone else ever heard the term "girtlin" (sp?) applied to a horizontal board on the outside of a vertical studwall used to hold siding?

I think it could be colloquial...

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Hi Kurt,

It might be colloquial. Girts are what one calls the horizontal members that connect adjacent bents in a timber-frame structure just below where the principal rafter and principal post meet. Then there are bent girts, which are at the same level but span the same bent. Purlins do exactly the same thing between bents but below the girt on the walls and above the girt on the roof. Today, most folks that aren't acquainted with traditional timber frame construction but are in construction would probably refer to the girt in a timber frame as either a top plate or a purlin, thus "girtlin."

My best guess.

ONE TEAM - ONE FIGHT!!!

Mike

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