Quote:
[/COLOR]As heero_yuy said, you only have to tap them with a hammer to hear them "ping" as they are under a large load.
Collar ties often cross from purlin to purlin when the purlin braces are not diagonal but vertical.
In some loft conversions, the purlins are replaced by steel girders, a major expense of the job, but they allow the removal of ties and braces.
|
Those purlin bracing is what i am proposing to do in my loft, they distribute any weight along the joists which is effectively what the joist is doing now in the center.
I find it odd there's only one 4x2 joist between the purlins. It doesn't appear to be doing anything significant that couldn't be worked around by distributing the weight down and across the joists, it would basically be the same and evenly distributed.
my Dad seems to thing they could have just put that there to hold the purlins in place while they cemented them in, he doesnt think its anything major.
I asked in the forum incase anyone is a structural engineer, or a builder, that could confirm my theory.