Rafter to Ridge connection

[rskinner (Robert Skinner, TREC #7081)]

Is there a distance/offset on either side of the ridge beam that rafters are allowed to be connected to ridge.
Typically rafters are adjacent to each other at the ridge beam.:roll:

[dduffy (Dale Duffy)]

**
They should be adjacent to each other.

R802.3 Framing details.
**Rafters shall be framed to ridge
board or to each other with a gusset plate as a tie. Ridge board
shall be at least 1-inch (25 mm) nominal thickness and not less
in depth than the cut end of the rafter. At all valleys and hips
there shall be a valley or hip rafter not less than 2-inch (51 mm)
nominal thickness and not less in depth than the cut end of the
rafter. Hip and valley rafters shall be supported at the ridge by a
brace to a bearing partition or be designed to carry and distribute
the specific load at that point. Where the roof pitch is less
than three units vertical in 12 units horizontal (25-percent
slope), structural members that support rafters and ceiling
joists, such as ridge beams, hips and valleys, shall be designed
as beams.

[rskinner (Robert Skinner, TREC #7081)]

I couldn’t find it in THE BOOK either. Today they were offset about 8 inches on either side.
Thanks for the response Dale.

[escanlan (Emmanuel Scanlan, TREC# 7593)]

2003 IBC:

2308.10.4 Ceiling joist and rafter framing.
Rafters shall be framed directly opposite each other at the ridge. There shall be a ridge board at least 1-inch (25 mm) nominal thickness at ridges and not less in depth than the cut end of the rafter. At valleys and hips, there shall be a single valley or hip rafter not less than 2-inch (51 mm) nominal thickness and not less in depth than the cut end of the rafter.

Don’t know why the IRC did not choose to use an exact extraction from existing codes.

[dduffy (Dale Duffy)]

@escanlan

2003 IBC:

Don’t know why the IRC did not choose to use an exact extraction from existing codes.

Then you wouldn’t have to buy both books… …wouldn’t want that now.

[escanlan (Emmanuel Scanlan, TREC# 7593)]

Dale,

Agreed!! If interested you can obtain an IRC membership and get a good discount on the entire, various code series including ANSI specs. But have you seen even the discounted price?

There was a lawsuit not long ago against a Texas resident who posted the entire code volumes on a WEB site. It sparked a big debate on having to even pay for on-line access to code manuals.

By the way did you see this one?

www.nfpa.org/newsReleaseDetails.asp?categoryID=488&itemID=29739

Would be nice if they could just all get along! But this is just another display that Codes have just turned into another money making business!!

[ccbrands1]

Just to add.

Want to put some thoughts to rest for myself.

Please correct anything that is incorrect or add:

1. A ridge board is not usually designed to carry any load, just something for rafters to attatch to. - except for in valleys ( not technically a ridge board )

2. Rafters connected to a ridge board rely on being directly accross from one another to help support the ridge of the roof.

3. Rafters that are offset from one another can cause undo stress on the ridge board itself being that there is no rafter opposite it.

[rrichards2]

@ccbrands1

Just to add.

Want to put some thoughts to rest for myself.

Please correct anything that is incorrect or add:

1. A ridge board is not usually designed to carry any load, just something for rafters to attatch to. - except for in valleys ( not technically a ridge board )

True

2. Rafters connected to a ridge board rely on being directly accross from one another to help support the ridge of the roof.

…to help counter the force being applied by the opposing rafter.

3. Rafters that are offset from one another can cause undo stress on the ridge board itself being that there is no rafter opposite it.

True

[dhelm (David E. Helm)]

@ccbrands1

Just to add.

Want to put some thoughts to rest for myself.

Please correct anything that is incorrect or add:

1. A ridge board is not usually designed to carry any load, just something for rafters to attatch to. - except for in valleys ( not technically a ridge board )

2. Rafters connected to a ridge board rely on being directly accross from one another to help support the ridge of the roof.

3. Rafters that are offset from one another can cause undo stress on the ridge board itself being that there is no rafter opposite it.

Yes true, unless plan requires structural ridge (eg when a large dormer is installed)

[roconnor (Robert J. OConnor)]

The IRC has no specific provisions for alignment of rafters when a ridge board is used, and I think that is reasonable given the relatively light lateral loads against a ridge board on typical house framing.

The IBC (applies to large multifamily and commercial) is more restrictive than the IRC as the loads are expected to possibly be higher than typical residential framing.

IMO it’s no big deal if there is a offset between rafters on either side of a ridge board for typical residential framing.

JMO & 2-nickels …

[escanlan (Emmanuel Scanlan, TREC# 7593)]

Robert you are absolutely correct (see below)! Thank you for pointing that out.

IBC:

101.2 Scope.
The provisions of this code shall apply to the construction, alteration, movement, enlargement, replacement, repair, equipment, use and occupancy, location, maintenance, removal and demolition of every building or structure or any appurtenances connected or attached to such buildings or structures.
Exceptions:
**1. Detached one- and two-family dwellings and multiple single-family dwellings (town houses) not more than three stories above grade plane in height with a separate means of egress and their accessory structures shall comply with the International Residential Code.
**2. Existing buildings undergoing repair, alterations or additions and change of occupancy shall be permitted to comply with the International Existing Building Code.

[rrichards2]

@roconnor

The IRC has no specific provisions for alignment of rafters when a ridge board is used, and I think that is reasonable given the relatively light lateral loads against a ridge board on typical house framing.

The IBC (applies to large multifamily and commercial) is more restrictive than the IRC as the loads are expected to possibly be higher than typical residential framing.

IMO it’s no big deal if there is a offset between rafters on either side of a ridge board for typical residential framing.

JMO & 2-nickels …

You are right Robert. The offset is not a big deal from a structural perspective and there may not be any code reference for it. However, good framing practices would have them directly opposed. This is the way I was taught by several Master Carpenters over the years. We all know that building code sets only a minimum standard. I certainly would not
buy a house that was built to minimum code standards.

Here I am in my younger days.

[ckratzer (Cy Kratzer)]

Ever try putting collar ties on rafters that aren’t adjacent to each other?
It looks/is 2nd rate and the fasteners don’t penetrate fully when every thing is angled to everything else.
I personally think if the house isn’t stacked from joist to rafter it’s not much of a house.
But that’s just me.

[dduffy (Dale Duffy)]

@rrichards2

You are right Robert. The offset is not a big deal from a structural perspective and there may not be any code reference for it. However, good framing practices would have them directly opposed. This is the way I was taught by several Master Carpenters over the years. We all know that building code sets only a minimum standard. I certainly would not
buy a house that was built to minimum code standards.

Exactly

[dduffy (Dale Duffy)]

@ckratzer

Ever try putting collar ties on rafters that aren’t adjacent to each other?
It looks/is 2nd rate and the fasteners don’t penetrate fully when every thing is angled to everything else.
I personally think if the house isn’t stacked from joist to rafter it’s not much of a house.
But that’s just me.

Ditto Ditto

[roconnor (Robert J. OConnor)]

@ckratzer

Ever try putting collar ties on rafters that aren’t adjacent to each other?

You actually don’t need collar ties (different from “rafter ties”) if you use metal straps to the ridge board. That is becoming pretty common around my neck of the woods with all the metal hurricane strapping that has to be installed anyway. So the old “collar ties” used to hold rafters against the ridge board is going the way of the dodo bird …

I agree it’s better practice to line up rafters. But what are ya gonna recommend? Correction by a framing contractor, or evaluation by an SE? In my mind the bottom line wearing my HI hat is that would be a non-issue that wouldn’t even get a comment as long as the rafter ends appeared to be adequately connected.

JMO & 2-nickels …

[rrichards2]

@roconnor

You actually don’t need collar ties (different from “rafter ties”) if you use metal straps to the ridge board. That is becoming pretty common around my neck of the woods with all the metal hurricane strapping that has to be installed anyway. So the old “collar ties” used to hold rafters against the ridge board is going the way of the dodo bird …

I agree it’s better practice to line up rafters. But what are ya gonna recommend? Correction by a framing contractor, or evaluation by an SE? In my mind the bottom line wearing my HI hat is that would be a non-issue that wouldn’t even get a comment as long as the rafter ends appeared to be adequately connected.

JMO & 2-nickels …

Ditto.

[lewens (Larry Ewens, C.M.R.I.C.)]

The sad thing about all this is that most of the new framing crews out there today would read this thread at not have a clue as to what was being discussed. That picture Roy posted brings back memories. That was when “carpenters” new what they were doing. I would hazard a guess that 90% of the so called carpenters out there today would not now how to read a rafter table and don’t even realize that a rafter square is a tool and not something with which to open a beer after work. I must admit that after using a rafter square all day long it does make a good tool to open that long awaited beer.
Larry