Mortar is the sacrificial layer of any roof or chimney. It is meant to fail before the tiles or bricks do, protecting the expensive materials by giving up first. That is fine — until the mortar has failed to the point where tiles are moving, water is entering the joint, and the fabric of the roof is exposed.
White Horse Roofing carries out repointing to ridges, hips, verges, chimneys and stonework across Oxfordshire, Berkshire and the Cotswolds. Every job is specified with the correct mortar for the age and construction of the roof — lime where required, cement where appropriate — and finished with a written workmanship guarantee.
Who it's for
Homeowners with visibly crumbling mortar along ridges and verges, mortar falling out of a chimney stack, or open joints in stone or brickwork. Owners of period properties where hard cement mortar has been used incorrectly and is causing tiles or bricks to crack. Buyers whose survey has flagged mortar failure.
When it's needed
As soon as mortar is visibly falling out of joints, ridges are moving under foot, or vertical rust stains appear below any brick or stone joint. Repointing done early prevents the tile or brick behind it from failing next — and it is always cheaper than the repair after the failure.
Why professional
Mortar choice is technical. Cement mortar on lime-built heritage properties causes the underlying tiles or bricks to crack as they can no longer move naturally. Lime mortar on modern cement-built roofs is over-specified and expensive. Getting the mix wrong accelerates the very failure you are trying to prevent — a common outcome of DIY and unqualified work.
