The edges of your roof are not just there to carry rainwater and melt from your doors and windows. Although this can be just as important as having decent eaves troughs and downspouts to convey the moisture further away safely.
The overhangs are also your primary line of defence preventing wind blowing back under your eaves, and forcing moisture into your roof itself. This may in turn help manage positive and negative pressures during wind storms.
However, those elements also require protection from bad weather too. Today we consider strengthening those defences. This is particularly important in high wind areas where storm damage may occur.
How Drip Edge Flashing Is a Critical Key
Drip edge flashing is there to prevent capillary action drawing water behind fascias towards rafter ends. This is particularly important if the boards are made from wood. Our image shows the two types we may use in tandem, depending on the design of the edges of your roof.
The Building America Solution Centre suggests the following for roof edges in sloping roof assemblies for residential construction in high wind areas.
1… Compliant metal drip edges at eaves and gables or rakes.
2… These should extend a half inch beyond roof sheathing.
3… They should be firmly fastened over secure underlayment.
4… Flashing cement should be applied over their upper edges.
Other Factors to Consider When Installing Your Roof Edges
The extent of the overhang is important too. You want sufficient coverage over your foundations, and immediate surroundings. However, you can also have ‘too much of a good thing’. That’s because the depth of the overhang affects the power of upward and downward wind pressure.
And finally, for now let’s not forget correct alignment of eaves troughs and eaves. If the roof stops short, moisture can pass behind the fascias and undo the benefits of your drip edges. There’s more to roofs than some service providers may consider important.
It could be worth your while to speak to Valiant first if you in live in Calgary and surrounds. We’ll include a free roof inspection when we quote for your asphalt roof repairs, replacement, or a new rain management system.
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