Tiled roofs have ridge capping.
These are the upside down Vee shaped elements at the top (ridge) and sloping side edges (hips) of your tiled roof.
These images show various stages of removing the old bedding and installing a new bed…
The ridge capping is held in position on a ‘bed’ of cement mortar. This is the bedding part.
Then when the bedding has set, a thin layer of pointing is applied over the exposed edge of the bedding. This is the pointing part.
More on Bedding and Pointing?
The series of You tube videos below provides a more thorough look at what bedding and pointing is all about:
Firstly, the ridge capping is held down and supported by a “BED” of (sand and cement based) mortar. Unfortunately, the bedding will crack as it naturally shrinks and it does not bind the ridge capping very well. Also, the colour of the bedding does not blend in with the colour of the roof tiles or the ridges. And this is where the pointing comes in…
In the (not too distant) past, the pointing was just a thin layer of oxide coloured sand/cement. The ‘cement’ pointing was put together relying on the skill of the roofer and the thin layer had a good chance of sticking onto the bedding without cracking.
With age and movement on the roof, the bedding (and attached pointing) would start to crack – and the ridge capping will then start to dislodge itself and sometimes slide off the roof. This is when the roof has to be “repointed” – to maintain the ridge security. Usually, only the very loose bedding is removed and fresh bedding installed locally to support the ridge capping. Then the rest of the existing (sometimes cracked) bedding is prepared to receive the new pointing.
Sometimes, when a main (horizontal) ridge has been laid without weep holes, A re-point will involve removing all the ridges and the old bedding.
This is to allow for the ridges to be freshly bedded to allow for weep holes to be correctly installed.
The video below shows the preparation work required just prior to the repointing process:
Once the old bedding has been prepared, it is repointed with flexible pointing. There are many brands of flexible pointing available nowadays – and we have used many of them. Nowadays, we have gone back to the original “FLEXIPOINT” – it just seems to work a bit better for us…
An old You tube video that I made a few years ago shows how the pointing is applied:
Flexible pointing is leaps and bounds ahead of the oxide cement pointing that exists on all old roofs. It sticks a lot better, has some flexibility against cracking – and is actually designed to be an alternative to mechanical anchoring of ridge capping onto the roof. It is pretty strong stuff that is very difficult to remove.
…But preparation is still the key – since even the stickiest compound will not stick to an un-prepared surface. Then it is in how the pointing is applied. The combination of the two will determine how effective (and the life) of the repointing job.
You can also see my blog post on ridge capping repair work and my youtube video below for a bit more information on ridge capping repair work:
Another video on re-pointing below.
Shows what your ridge capping should look like after they have been prepared for re-pointing, then re-pointed with “Flexipoint”: