When Dropped Mitre Corners Count

You are highly unlikely to find much on this topic when you search on the internet. Notwithstanding this, there are times when dropped mitre corners are the only way to avoid annoying drips and leaks.

A mitre is a corner gutter section where two gutter lengths join at a nominal right angle. We say ‘nominal’ because there is no such thing as a perfectly square house.

Most times we can correct these imperfections with a push, a shove and a good dollop of sealant, although there are times when dropped mitre corners really are the only way to go.

Why Mitres May Drip Water At Corners

However, before embarking on this time-consuming alternative, it may pay you to investigate why your eaves troughs are leaking. This could be for some reason other than horizontal misalignment at an outer or inner corner. Here are a few places to start looking for the cause:

  • Begin by viewing the corner from below to spot which mitre, and which end of it is leaking. Tell-tale signs may include persistent dripping after rain or snowfall, and also an accumulation of green mildew or mould.
  • However, if the gutter is well-aligned and the joints are clear, then there’s a possibility the gutter is blocked. Or perhaps, a down pipe nearby is clogged with debris. Either of these can cause the eaves trough system to overflow.

Poorly Installed Eaves Trough Systems

Water can flow at a surprisingly high rate during heavy rains. Mitre gutter corners interrupt this flow, as they cause it to change direction. Therefore, it is essential to ensure that the width of the gutters, and the diameter of the down pipes are both able to cope with heavy rain.

If this is not the case, or the gutter pitch is incorrect or inconsistent, then the water may dam at the corners, and lap over the mitres.

A skilled gutter installer knows how to correct an incorrectly pitched run of gutter. However, they should not do this if the gutter lengths are horizontally mis-aligned at this point.

when dropped mitre cornersDropped Mitre Corners For Misaligned Gutters

Please take a second look at that picture directly above from another of our projects. Notice how the two gutter runs come together at different heights, because of inconsistent architectural design.

We use this fairly extreme example of when dropped mitre corners are essential to illustrate a point. However, in many other cases you’ll hardly notice how we correct horizontally misaligned gutter mitres on our Valiant Exteriors jobs.

More Information

Installing a Gutter From a MEWP

Gutter End Caps For Imperfect Roofs

Correctly Aligned Gutter Corner © Valiant Exteriors