Door Bolts & Security Chains
To add additional security to most household external doors it is advisable to add extra door bolts. These can be in the form of either surface door bolts (barrel bolts) or mortice door bolts, commonly called ‘Chubb’ bolts or mortice star bolts, since they use a star shaped splined key to operate them.
External Door Attachments
Door bolts of one type or another will always be needed on a pair of external doors which are being fitted with a mortice lock, typically a pair of French doors. The bolts are required to keep the first or slave door fixed shut for the main door to close and lock onto. Without bolts the lock would be superfluous, as the doors could just be pushed open.
When fitting pairs of external doors it is common to use flush bolts. These are partially concealed bolts and flush to the door surface, thus securing the slave door. Usually these bolts are hidden in the joining rebate of the two doors. Hiding the bolts in this way is more secure as the slave door can not be opened until the main door has been unlocked.
Straight Bolt Systems
Normally straight door bolts are used on the opening face of the door and cranked door bolts are used on the closing face. However, there are many straight bolt systems available with a variety of keeps which will operate on both sides. Please ensure you select the correct type of bolt for your application. If you have any doubts please contact customer services for advice.
Door chains, which are now an NHBC requirement on new homes, come in several designs. As the name suggests, they restrict the door from opening when the chain is engaged. Mostly they are fitted to the main entrance door of a dwelling.