when is a drip edge required? We are building a home but have not included gutters at this point. Should our builder still apply the drip edge or other type "flashing"
I've never seen a roof without drip edge. It protects the edge of the shingles, and carries the water away from the trim. On our house, they didn't install it correctly- they butted it instead of overlapping, and everywhere it butted, the wood underneath had rotted. I can't imagine what would would happen if you didn't have any.
The point of the drip edge is to protect the edge of the roof's underlayment from moisture, and to do the final guide of rainwater from shingle into gutter. And as flgargoyle pointed out, if it isn't installed properly, it's a quick way to rot.
The point of gutters is the collect the rain which has fallen on the roof, and carry the water away from the house foundation. Dispersement methods (instead of gutters) guide the rainwater onto an angled ledge and encourage it to spray outwards, away from the house foundation. Unguttered roofs quickly develop a trench-like water line in the soil directly below the roof's edge, which can pound plants to mush while guiding the water *toward* the foundation -- a big no-no both because you don't want damp basements and because the mass of water can eventually de-stabilize the foundation, leading to cracks or worse.
Keep in mind that even in a light rainfall, a smallish roof can quickly collect several hundred gallons of water. You really don't want that water saturating the soil beside your house.
The purpose of a drip edge is to make water drip downward instead of being drawn back up under the edge. It should be at the eave where WR Grace Ice & Water Shield (no substitutions) self-adhering flashing overlaps it and at the rake (sloping edge) where it overlaps the underlayment.
A drip edge is normally entirely independent of the gutter system although it is possible to create a gutter where the back face continues up under the roofing in place of the drip edge but it is expensive.
It is always good to get details of these conditions to avoid misunderstandings. In a cold climate, if you plan to add gutters later, make sure the eave facia board is tall enough so that the gutter can be set below the projected line of the roof plane so ice won't destroy the gutter.
If you intend to hang a half-round gutter, size it larger than a box (K) type gutter and make sure the roof edge projects enough so there is room for the suspended gutter. If you know you will install gutters later install the hangers rods now so they will be under the shingles and over the flashing and drip edge.
The 'dispersment methods' Meldy referred to: How effective are they?
I've never seen them used.
I've only seen the diverters used on one house, a 2-story on a slope, standard shingled roof, on a wooded lot. Please note that my locale is subject to severe wind & rain storms. According to the owner, they worked fine in normal rains sending the roof water outwards in a spray, but severe rain would instigate a sheet of precipitation that closely resembled a waterfall. The owner decided he wasn't happy having the water spray blown back onto the house sides which seemed to happen whenever there were winds along with the rain, and eventually (I think about 2 years later) replaced them with standard gutters. I don't remember that there were any other negative comments, so this is not a negative recommendation... just be careful to suit the style of diverter to your climate. Personally, I'd rather be positive that the water was taken away from the foundation area, and that means using gutters sized to fit the potential rainfall.
Thanks, meldy, for the explanation. It's so hard getting gutters that are 24' off the ground cleaned. I didn't want to miss any good alternatives! Sounds like this is not one. Every rain would be a waterfall!
There are various shields (mostly either net-type or an overlapping design) sold with the promise to keep leaves and other debris out of the gutters. I have not heard or experienced 100% satisfaction with any of them. OTOH, the dis-satisfaction seems to occur in direct relation to the number and types of trees in the area, lol.
I have no personal experience with the overlapping sort, but those who like them love them, and those who don't, don't. Since my area often has truly heavy rains, and a neighbor noticed that really heavy rain had a tendency to shoot *over* his catchment gutter instead of the water curling down into the gutter, I didn't even consider putting the overlap-type on. I do think that they would be okay in areas not prone to tropical storms, but they just aren't quite right for my locale. My experience is with both plastic and aluminum mesh-types, and I prefer the very fine-meshed plastic. My present house is surrounded by pin oaks, maples, pines, hickory and several other types of oak. The first three listed are the prime offenders for producing gutter blockages. Oh yeah, that they are. Anyway, I have the gutters checked once a year (I'm too old for playing on the roof) and since installing the fine mesh covers, have not had any difficulties with leaves, pine needles, maple spinners or other stuff blocking them. The coarse-mesh plastic was not sufficient to stop pine needles, maple spinners, or the oak bloom. The aluminum had mesh that was a bit too coarse and several sections were damaged by branches during one the storms. The fine-mesh has been up for several (8?) years, and has done just fine, apparently just flexing when a branch hits.
It's worth saying that even the plastic mesh guards are not cheap, and the cost is in addition to the gutters, so the total can be quite a bill. However, it sure beats being at the top of a 40-foot ladder scooping out gunk every couple weeks all autumn.