Roof Flashing

[danho]

Hey guys,

Getting ready to install some 3' wide Delta Rib metal roofing on my new pole barn and was wondering your thoughts on drip edge or flashing along the edges. Standard roof with 2 gables and 2 eaves with no other areas of concern and also no sheathing just the purlins.
If it serves a purpose I'm all about it, otherwise I personally am trying to see the benefit.

 

[danho]

Bump.

 

[rburke65]

danho, did the seller of the metal roofing offer the trim pieces to finish the roofing project? I have installed a simple metal roof on my pole barn and purchased the metal from a local lumberbyard. The manufacturer had a catalog with every conceivable trim piece you would ever need.

 

[danho]

They have all the trim and flashing available at the manufacturer and in talking to them, some people put drip edge on and some don't. Just trying to see if there is a reason for either.

 

[rburke65]

I always thought the purpose of the drip edge was to prevent water from being wicked back up into the roof decking .... Assuring that the water/rain would drip off and away and possibly into a rain gutter. Hey....Google it!

 

[danho]

Hey....Google it!

Been done, that's the reason for the question. I do not have roof decking/sheathing, only purlins and was wondering what people on here have done.

Thanks for the reply though.

 

[Doug B]

I would go with this type of rake trim. Let the metal hang over the eaves edge by 2"

 

[danho]

Thanks for the reply Doug, but therein lies my question. On a building without roof decking, is that rake trim and drip edge flashing actually needed or is it for aesthetics only? I mean, I can overhang the metal roofing itself by 2" on the gable and eaves.

 

[jack stand]

Besides adding "watertightness" It also adds strength to the edge, being continuous with the additional bends. This will help keep your metal where you want it in high winds. The edges are a vulnerable area. Also, unless your lucky, most roof's will not end (the last panel) even. That is it might be 27" at the top, and 28" at the bottom, and as luck has it, this is usually "over" a big rib. You can hide some of these issues with gable edge trim. At the soffit or eave (where the gutter might be), I don't think a drip edge is really necessary if you leave a generous 2"+ overhang.

 

[Doug B]

Thanks for the reply Doug, but therein lies my question. On a building without roof decking, is that rake trim and drip edge flashing actually needed or is it for aesthetics only? I mean, I can overhang the metal roofing itself by 2" on the gable and eaves.

Not needed. Letting the metal overhang the rakes and eaves by 2" should work.

 

[why worry]

Being a sheet metal worker who has fixed leaks for years on improperly installed roofs. I would most definitely install the eave flashing with closure and rake flashings that were shown in DougB's post. The reason for them is to prevent wind driven rain from wicking back up and into the building. You would be surprised how often it happens.

Why Worry

 

[plow]

Sorry for the hijack, but is there a tutorial for skinning the entire building from stsrt to finish?

 

[rburke65]

Have you tried YouTube for metal roofing? If I can do it you can do it. Start with the drip edge, then the metal sheets. You will have a ridge cap and then your rake trim. I don't think there is much more.

 

[Catadj78]

I don't know why you would not want to install it? Looks much nicer and it isn't that expensive at all

 

[plow]

Have you tried YouTube for metal roofing? If I can do it you can do it. Start with the drip edge, then the metal sheets. You will have a ridge cap and then your rake trim. I don't think there is much more.

No, but I will. Thanks.