Tiled Roofs like Sahara Desert

[rod1949]

I bussed it to work this morning and as we're traversing the back streets of suburbia I couldn't help but notice tiled roofs on lots of older (20-30yrs)houses are up and down like the Sahara Desert. I guess its from the bending, twisting and ageing of the timbers used, and a potential problem/s that the owners are probably oblivious too.

[DvdHntr]

Timber isn't supposed to last forever but 20-30 year old roofs, if they were designed properly should still be pretty good. I don't know much about the design methods back then but I guess they didn't take the creep of the timber into account as much as they should or at all.

[Tools]

Or from DIYers removing load bearing walls and props.........

Tools

[Barry_White]

Or builders using crapiata roof trusses.

[ausdesign]

Nah. I reckon it's the creep.

[OLDPHART]

Unseasoned timber more likely

[echnidna]

nope, not built straight originally if a stick roof or the trusses were too light or installed outa whack.

usta see it a lot on brand new estates with stick roofs

[pawnhead]

I've seen a lot of old roofs where the members are way over spanned.
I framed up for a huge slate roof once and it had to be spot on. Slate really shows up any irregularities in the flatness of the roof plane.

My next door neighbour has just built a new house and there's a twist in the roof of at least six inches.

[Andy Mac]

Unseasoned timber more likely

My folk's house on the farm in WA was built in the mid 70's, with a Jarrah frame, and it developed a huge droop along the main ridge. I worked as a carpenter's off-sider a bit later, and a lot of that framing timber was used green, unseasoned (sap squirting out stuff), with the advantage of being able to sink a nail into it, back in the days before nail guns ...intentionally I don't know. Anyway the house had a tile roof which added weight to what was possibly a supple frame, but should a trussed roof balance out such stresses, I have no idea?

Cheers,