To ensure everything fits together neatly, our cast iron rainwater system uses internal and external pieces to couple the gutters to the fittings.  Deciding whether something is internal or external can be confusing so we have put together the graphics below to help you.

On symmetrical cast iron gutters such as the common half round you simply turn the gutter angle around to suit internal or external corners on the roof.  With the cast iron ogee gutters where the profile is asymmetrical, you need to order the correct type of angle – internal or external.

With ogee stop ends, because of the profile of the gutter they are handed – either right hand or left hand.  Stop ends are always handed when looking from the front.  Stand in front of the gutter and you will require an external stop end to cap off the end to the right, and an internal stop end to cap off the left hand end.  This also applies to the drop end outlets.