Ridge Tile help

[zappastix]

Hi

One Redland "half round ridge tile" on a gable garage has been blown down
(it's the first one - the others look okay).

And a number of same style ridge tiles on some of the 'hips' on the property have come loose
and fallen down resting on the Roman interlocking tiles.

On the hips where the ridge tiles have fallen away I can see a "gap" running all the way up.

The gap is direct centre where the ridge tiles would sit.

The ridge tiles and the roof tiles and Redland cast concrete.

None of the tiles/ridge tiles are mechanically fixed.

Of course I'll remove the old bed to make a fresh start.


I have a few questions.

Should I fill in this gap with the same mix that I'll use to fix new ridge tiles in place?

Or is this gap some sort of ventilation - and should it be left open?

I know this seems to be an old chestnut - but what mix should I use?

So you know the property is very close to the English Channel and subject to very strong gales
through the winter.

Should I use a mix of soft builders sand AND sharp sand?

The ratio of what you'd use for this 'exposed' location would be helpful.

Also, what about Liquid Mortar Plasticiser YES/NO?

I can't remember the name but what about an additive to help set the mix of a bit quicker as I'll be doing this now in the cold.

So ratios please;

Cement / Builders Sand OR Cement / Builders Sand + Sharp Sand

And if recommended can I mix Liquid Mortar Plasticiser WITH "rapid additive" or can you only
use one or the other?

Just thought one other question - do I fill the HALF ROUND with mix OR do I set the ridges tiles
on bed leaving a space between ridge tiles and just point them?

To me it seems like it would be a lot stronger packing the mix in the 1/2 round hole - this is my first time so I have no idea.

Many thanks in advance.


Stephen

 

[mfarrow]

There are some good articles and advice out there. Mix should be 3:1 with perhaps one of the sand parts being sharp.

Best not to add any unnecessary additives. SBR would work well as an adhesion aid but be warned it can reduce workability time.

I wouldn't add anything to speed things up.

 

[tony1851]

1:3 cement: sharp sand is the usually-specified mix for ridge/hip tiles, but it is not easy to work unless a
plasticiser is added.

As mfarrow, suggest substitute some builder's sand with the sharp stuff.

If you add a plasticiser, that will reduce the amount of water needed, which helps in cold conditions.

When I re-did our hip/ridge tiles years ago, I packed the whole void with mortar, and none has moved
despite the gales.