How to repoint ridge tiles

Inspired by a practical UK roofing guide. This walk-through draws on the video "Repointing Ridge Tiles with Flexim Roofing Putty", filmed on a real UK job in Nottinghamshire. It covers both cost and method, and the comparison between flexible putty and traditional mortar is genuinely useful if you are deciding which route to take. Worth watching before you order materials.

1. Inspect the ridge from ground level first

Use binoculars from the ground before you go anywhere near a ladder. You are looking for missing mortar, cracked pointing, or any ridge tile that has shifted out of line. A tile that has moved even a centimetre can let driven rain under the edge.

If more than a third of the ridge needs attention, it is often more efficient to lift and re-bed all the tiles in one go rather than patch-repoint in sections. That said, if it is just a couple of joints, targeted repointing is fine.

2. Set up safe access

A ridge job means working at height. Use a proper roof ladder that hooks over the ridge rather than leaning against tiles - ordinary ladders damage clay or concrete tiles. Make sure someone knows you are up there and have a mobile in your pocket.

Do not go up in wet or windy conditions. The ridge is the highest point of the roof and the most exposed. There is no heroics prize for working in the rain.

3. Rake out the old mortar

Use a cold chisel and club hammer to carefully break away the old bedding mortar from around and beneath each ridge tile you are repointing. Work methodically from one end of the ridge to the other. Old mortar often has gaps already, which makes it easier - it can sometimes be lifted off in sections.

Brush off all debris with a stiff brush. The surface needs to be clean and dust-free for either mortar or flexible putty to bond properly. Any loose bits of old pointing left in place will undermine the new work.

4. Choose your pointing material

Traditional sand-and-cement mortar (typically a 3:1 mix with a plasticiser) is cheaper but rigid. It cracks over time as the roof moves with temperature and wind. That is why it keeps needing doing every decade or so.

Flexible roofing putty products have become very popular in the UK trade. They stay pliable once cured, which means they can accommodate movement without cracking. The material costs more per job, but the result typically lasts significantly longer. For most domestic properties, flexible putty is now the better long-term choice.

5. Apply the new bedding and repoint

If using flexible putty, apply it into the joint and along the bedding with a pointing trowel or squeezable applicator gun. Work it firmly into all voids under the tile edges and along each side joint. Smooth off with the trowel for a neat, slightly recessed finish that sheds water cleanly.

If using mortar, dampen the surface first so the dry tile does not suck moisture out of the fresh mix too quickly. Press the mortar firmly into the joint and tool it to a slight angle so it directs water away from the tile edge rather than holding it.

6. Check mechanically fixed tiles

Modern Building Regulations and good practice guidance recommend that ridge tiles are mechanically fixed - nailed through into the tile batten or rafter - as well as bedded. If your tiles are just sitting in mortar with no nail or clip, it is worth fitting stainless steel ridge tile clips at the same time as repointing. They are cheap and they stop tiles lifting in high wind.

Leave the new pointing to cure for at least 24–48 hours before heavy rain. If it rains shortly after, cover the ridge loosely with a sheet if you can. Not always practical, but worth doing when possible.

When to call a handyman

Repointing ridge tiles is a reasonable DIY job if you are confident at height and comfortable on a roof ladder. But if the ridge line is long, the tiles are coming away, or you are not sure what is underneath, it is safer and more cost-effective to have a professional handle it. Richard can assess the ridge from ground level first and advise honestly on what is needed.