On Wed, 22 Dec 2004 09:00:56 -0800, "Roger Shoaf"
wrote:


jim wrote in message ...

To be honest, I haven't seen too many roof rafters of any size fail
tho I have seen some. Usually other factors contribute to this. But
lets face it, usually roof rafters don't fail as evidenced by the
older houses. I say "usually" not never.


I have 6 rental houses all built by the same guy. From the birds mouth to
the ridge they are a little over 10 feet and all of the 2X4 rafters have at
least 3/4" sag in the middle. They had no cross bracing or trussing of any
sort. I just rebuilt one of the roofs but this time I used steel rods to
jack the sag out of the roof. 1 down 5 to go.

The sag was not a failure per se. They were still supporting the sheeting
and were probably to code, but the sag made the roof look like hell.

Conversely, my residence built around the same time was built by a real
carpenter and the roof is nice and flat as he took the time and lumber to
build it right.


Normally you won't see 2x4s as rafters unless in small enclosures.
As you pointed out, your 2x4s may not fail for strength by code but
may or may not meet the code for deflection. Just for others benefit,
usually 2 criteria are involved in designing a structure.... strength
and deflection. They are independent of each other and specified by
code.

I too own other houses but haven't noted any roof problems when I
owner financed them to others. None of them had 2x4's as rafters.
Now if it happens it's their worry grin.