Crown of the Corrugation

Couldn,t get you guru , pls xplain in detail .

Thks for your prompt response ,

How does it affect structurally if bolting arrangements is carried out on the valley.

Regards

Earnest.

Is the original poster missing a card from his pack?

That's an interesting possibility.

Speaking from a strictly structural standpoint, disregarding leakage, attaching the roof by screwing into the valley instead of the crown would probably yield a physically stronger structure.

But that structure would be much more prone to leaking and subsequent water damage, as PWSlack has said.

So, it might make for a slightly stronger roof, but don't do it.

In most pre-engineered steel buildings I have seen, the advice so far is correct... for the roof.

Most PEB I have seen fasten the vertical panels thru the panel valleys into the girts. In addition, most PEB buildings I have seen use a standing seam roof in lieu if the corrugated panels. This is a custom that can change with locale, and may not be applicable to our original poster.

Reference is also made to an applicable code. What code?

I know i dont need to post this, cause its been answered, but think about the correlation between gravity, water, and the shape of the roofing iron. Wheres the water gonna go? In the lowest part, and in turn, most likely into your roof space, thats why they are on the top and not in the recess. There is no technical advantage (its common sense), but there is a practical advatage. As the last poster said, most times they are screwed in the recess when attaching the iron to a vertical surface (eg the walls of a shed etc). Dont think about it to much, its just a roof, its there to act as a barrier between you and the forces of nature, so just go with what works, and screw them in the crowns on your roof.

You have a real problem, called common sense.

On either case: regarding leakage and structural standpoint, which of the following case is impresive, check it out yourself...

If i have understood you well i think this is straight forward,during storm water always runs on the troughts,on the crowns structure facilitates water to drain onto the troughts and so if there is the gap btn roofing material and bolting/nail as it is mostly the case..(in this case fastening agent) water dont get enough time to penetrate between the gapes(bear in mind roofing fastening agents eg nails,bolts ets they are always fastened with wider caps)....contraly to that at normal circumstances,your roof will be prone to leakage..

If you're bolting it on, you can't get your spanners in the valley

CNC

There are quite normal tools around that will allow it to be tightened adequately.......it does not always have to be wrenches/spanners.....Buy a socket set!!

........though one could use a socket set.

'........though one could use a socket set.'

'There are quite normal tools around that will allow it to be tightened adequately.......it does not always have to be wrenches/spanners.....Buy a socket set!!

__________________
"Six months ago I could not spell 'Engineer', now I are one!"'

OK PW and Andy. I was joking I do like a witty comment but I don't like to see threads hijacked by irrelevance.

Hey, you started that!!!

All good common sense answers.

Something else to think about -- a disadvantage to fastening to the crown is the corrugation will grow in width as the fastener is tighten.

There many ways to fasten a corrugated deck to a structure that can not be done on the crown. Powder actuated fasteners are designed to be fasten to the low side. The (never on any of my projects) awful puddle welds are another.

I have not read this code, but does it only apply to the fastening of the corrugation to the structure or does this also include fastening of insulation and cover boards to the corrugation?

what code and line number are you referencing?

Its Indian Standard BIS 12093...

Regards

Earnest.

I use corrugated "plastic" panels on my dog kennel roof and fastened them in the valleys with supplied screws that have rubber washers under the screw head. Yes they attach with a screw gun and a small socket. The reason I used the valley is to allow the use of a "snow rake" to remove snow in the winter. If the screws were on top, the rake would catch on them. As it is I have no leaks from the screw attachments...only from where I accidentally punched a hole with the roof rake! The "normal" recommended procedure is to attach to the crown, as stated elsewhere.

When using mechanical fasteners on corrugated sheet you will get less leaking of moisture by going through the crown.