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Commercial sealing lugs are not always of sufficient length to guarantee a foolproof anchoring of door or window frames.
To improve the fixing, make elements by welding perpendicular to a length of angle a flat iron ending in "tail of carp" (the end is split and flared). Then screw these elements into the outer rebate of the jambs of your opening.
Provide at least four fixings per window and six per door, to be fixed facing the hinges.

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