Lateral restraint in old buildings

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Many older buildings were constructed of thick stonework and lime mortar. This lime mortar is relatively weak and would have been used primarily for bedding as opposed to bonding of the stone.

Lateral restraint was provided by the floor joists, roof and internal spine walls; the floor joists were normally built into the walls but the mortar would break down over time and the restraining abilities would be reduced. In some buildings, you might see restraint provided by buttresses. In modern construction, ceiling joists are mechanically fixed to the walls with galvanised steel joist hangers which provides greater stiffness to the building.

Cracking or bulging walls are the main sign of lateral restraint failure and this property in North Cork was suffering from serious vertical cracking along both gables. The opening up of previous repairs suggested that damage was progressive with movement being compounded at one gable where the stairway was located.

Unfortunately for Substruck, this cracking was not foundation movement related. Remediation should primarily focus on the root cause as well as the effects. There are several solutions to arrest the movement; a more traditional approach would be tie bars with pattress plates installed to both elevations to provide enough restraint. These ties may be installed parallel to the floor joists at first floor level.

If you have concerns about any type of cracking, please drop us an email with some photos on